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1.  Gait adaptations in low back pain patients with lumbar disc herniation: trunk coordination and arm swing 
European Spine Journal  2010;20(3):491-499.
Patients with chronic non-specific low back pain (LBP) walk with more synchronous (in-phase) horizontal pelvis and thorax rotations than controls. Low thorax–pelvis relative phase in these patients appears to result from in-phase motion of the thorax with the legs, which was hypothesized to affect arm swing. In the present study, gait kinematics were compared between LBP patients with lumbar disc herniation and healthy controls during treadmill walking at different speeds and with different step lengths. Movements of legs, arms, and trunk were recorded. The patients walked with larger pelvis rotations than healthy controls, and with lower relative phase between pelvis and thorax horizontal rotations, specifically when taking large steps. They did so by rotating the thorax more in-phase with the pendular movements of the legs, thereby limiting the amplitudes of spine rotation. In the patients, arm swing was out-of phase with the leg, as in controls. Consequently, the phase relationship between thorax rotations and arm swing was altered in the patients.
PMCID: PMC3048239  PMID: 21181483
Gait coordination; Trunk movements; Relative phase; Low back pain; Arm swing
2.  Improving prehospital trauma management for skiers and snowboarders - need for on-slope triage? 
Injuries from skiing and snowboarding became a major challenge for emergency care providers in Switzerland. In the alpine setting, early assessment of injury and health status is essential for the initiation of adequate means of care and transport. Nevertheless, validated standardized protocols for on-slope triage are missing. This article can assist in understanding the characteristics of injured winter sportsmen and exigencies for future on-slope triage protocols.
Six-year review of trauma cases in a tertiary trauma centre. Consecutive inclusion of all injured skiers and snowboarders aged >15 (total sample) years with predefined, severe injury to the head, spine, chest, pelvis or abdomen (study sample) presenting at or being transferred to the study hospital. Descriptive analysis of age, gender and injury pattern.
Amongst 729 subjects (total sample) injured from skiing or snowboarding, 401 (55%, 54% of skiers and 58% of snowboarders) suffered from isolated limb injury. Amongst the remaining 328 subjects (study sample), the majority (78%) presented with monotrauma. In the study sample, injury to the head (52%) and spine (43%) was more frequent than injury to the chest (21%), pelvis (8%), and abdomen (5%). The three most frequent injury combinations were head/spine (10% of study sample), head/thorax (9%), and spine/thorax (6%). Fisher's exact test demonstrated an association for injury combinations of head/thorax (p < 0.001), head/abdomen (p = 0.019), and thorax/abdomen (p < 0.001).
The data presented and the findings from previous investigations indicate the need for development of dedicated on-slope triage protocols. Future research must address the validity and practicality of diagnostic on-slope tests for rapid decision making by both professional and lay first responders. Thus, large-scale and detailed injury surveillance is the future research priority.
PMCID: PMC3098779  PMID: 21521524
skiing; snowboarding; triage; prehospital care; injury
3.  Anterior thoracic posture increases thoracolumbar disc loading 
European Spine Journal  2004;14(3):234-242.
In the absence of external forces, the largest contributor to intervertebral disc (IVD) loads and stresses is trunk muscular activity. The relationship between trunk posture, spine geometry, extensor muscle activity, and the loads and stresses acting on the IVD is not well understood. The objective of this study was to characterize changes in thoracolumbar disc loads and extensor muscle forces following anterior translation of the thoracic spine in the upright posture. Vertebral body geometries (C2 to S1) and the location of the femoral head and acetabulum centroids were obtained by digitizing lateral, full-spine radiographs of 13 men and five women volunteers without previous history of back pain. Two standing, lateral, full-spine radiographic views were obtained for each subject: a neutral-posture lateral radiograph and a radiograph during anterior translation of the thorax relative to the pelvis (while keeping T1 aligned over T12). Extensor muscle loads, and compression and shear stresses acting on the IVDs, were calculated for each posture using a previously validated biomechanical model. Comparing vertebral centroids for the neutral posture to the anterior posture, subjects were able to anterior translate +101.5 mm±33.0 mm (C7–hip axis), +81.5 mm±39.2 mm (C7–S1) (vertebral centroid of C7 compared with a vertical line through the vertebral centroid of S1), and +58.9 mm±19.1 mm (T12–S1). In the anterior translated posture, disc loads and stresses were significantly increased for all levels below T9. Increases in IVD compressive loads and shear loads, and the corresponding stresses, were most marked at the L5–S1 level and L3–L4 level, respectively. The extensor muscle loads required to maintain static equilibrium in the upright posture increased from 147.2 N (mean, neutral posture) to 667.1 N (mean, translated posture) at L5–S1. Compressive loads on the anterior and posterior L5–S1 disc nearly doubled in the anterior translated posture. Anterior translation of the thorax resulted in significantly increased loads and stresses acting on the thoracolumbar spine. This posture is common in lumbar spinal disorders and could contribute to lumbar disc pathologies, progression of L5–S1 spondylolisthesis deformities, and poor outcomes after lumbar spine surgery. In conclusion, anterior trunk translation in the standing subject increases extensor muscle activity and loads and stresses acting on the intervertebral disc in the lower thoracic and lumbar regions.
PMCID: PMC3476747  PMID: 15168237
Posture; Sagittal alignment; Intervertebral disc; Biomechanics; Spinal load
4.  Effect of Trunk Sagittal Attitude on Shoulder, Thorax and Pelvis Three-Dimensional Kinematics in Able-Bodied Subjects during Gait 
PLoS ONE  2013;8(10):e77168.
It has been shown that an original attitude in forward or backward inclination of the trunk is maintained at gait initiation and during locomotion, and that this affects lower limb loading patterns. However, no studies have shown the extent to which shoulder, thorax and pelvis three-dimensional kinematics are modified during gait due to this sagittal inclination attitude. Thirty young healthy volunteers were analyzed during level walking with video-based motion analysis. Reflecting markers were mounted on anatomical landmarks to form a two-marker shoulder line segment, and a four-marker thorax and pelvis segments. Absolute and relative spatial rotations were calculated, for a total of 11 degrees of freedom. The subjects were divided into two groups of 15 according to the median of mean thorax inclination angle over the gait cycle. Preliminary MANOVA analysis assessed whether gender was an independent variable. Then two-factor nested ANOVA was used to test the possible effect of thorax inclination on body segments, planes of motion and gait periods, separately. There was no significant difference in all anthropometric and spatio-temporal parameters between the two groups, except for subject mass. The three-dimensional kinematics of the thorax and pelvis were not affected by gender. Nested ANOVA revealed group effect in all segment rotations apart those at the pelvis, in the sagittal and frontal planes, and at the push-off. Attitudes in sagittal thorax inclination altered trunk segments kinematics during gait. Subjects with a backward thorax showed less thorax-to-pelvis motion, but more shoulder-to-thorax and thorax-to-laboratory motion, less motion in flexion/extension and in lateral bending, and also less motion during push-off. This contributes to the understanding of forward propulsion and sideways load transfer mechanisms, fundamental for the maintenance of balance and the risk of falling.
PMCID: PMC3812214  PMID: 24204763
5.  Reliability and validity of spinal coordination patterns during treadmill walking in persons with thoracic spine pain – a preliminary study 
Persons with low back pain fail to show the same transition as healthy individuals from in-phase to anti-phase rotation of the thorax and pelvis as walking speed increases. The purpose of this study was to determine if the relative phase of the thorax and pelvis during walking was a reliable (within day test-retest) and valid measure for persons with thoracic pain.
The time series motion of the spine over C7, T8 and sacrum were measured at five treadmill walking speeds (0.67, 0.89, 1.12, 1.34, 1.56 m/s) in 19 persons with thoracic spine pain and 19 healthy control subjects. After a 20 minute rest, all tests were repeated. The average relative phases of the transverse plane rotation between C7-T8, C7-sacrum and T8-sacrum during a one-minute walk were calculated. The standard error of measurement (SEM) and the intra-class correlation coefficient (ICC) were used to estimate test-retest reliability. Three-way repeated measures analyses of variance were performed to determine the influence of group, walking speed and session on the relative phases.
The minimum transverse plane motion amplitudes, across all participants and speeds, for the C7-T8, C7-sacrum, and T8-sacrum were 2.9, 5.1 and 2.8 degrees, respectively. The C7-T8 relative phase changed little with speed. The C7-sacrum and T8-sacrum relative phases showed increases as subjects walked faster, but both groups had similar patterns of change. Only the C7-T8 relative phase at 0.67 and 0.89 m/s exhibited good reliability (ICC > 0.80, SEM 4.2-5.7, no significant time effects) for both groups. The C7-T8 and T8-sacrum relative phases demonstrated significant group by speed effects.
The C7-T8 relative phase showed reasonable reliability and some discrimination between groups, but changes in response to walking speed were small. The T8-sacrum relative phase showed some discriminative ability, but reliability was not adequate.
PMCID: PMC4029448  PMID: 24321275
Thoracic spine pain; Gait; Spinal coordination; Reliability; Validity
6.  Investigation of the usability of conebeam CT data sets for dose calculation 
To investigate the feasibility and accuracy of dose calculation in cone beam CT (CBCT) data sets.
Kilovoltage CBCT images were acquired with the Elekta XVI system, CT studies generated with a conventional multi-slice CT scanner (Siemens Somatom Sensation Open) served as reference images. Material specific volumes of interest (VOI) were defined for commercial CT Phantoms (CATPhan® and Gammex RMI®) and CT values were evaluated in CT and CBCT images. For CBCT imaging, the influence of image acquisition parameters such as tube voltage, with or without filter (F1 or F0) and collimation on the CT values was investigated. CBCT images of 33 patients (pelvis n = 11, thorax n = 11, head n = 11) were compared with corresponding planning CT studies. Dose distributions for three different treatment plans were calculated in CT and CBCT images and differences were evaluated. Four different correction strategies to match CT values (HU) and density (D) in CBCT images were analysed: standard CT HU-D table without adjustment for CBCT; phantom based HU-D tables; patient group based HU-D tables (pelvis, thorax, head); and patient specific HU-D tables.
CT values in the CBCT images of the CATPhan® were highly variable depending on the image acquisition parameters: a mean difference of 564 HU ± 377 HU was calculated between CT values determined from the planning CT and CBCT images. Hence, two protocols were selected for CBCT imaging in the further part of the study and HU-D tables were always specific for these protocols (pelvis and thorax with M20F1 filter, 120 kV; head S10F0 no filter, 100 kV). For dose calculation in real patient CBCT images, the largest differences between CT and CBCT were observed for the standard CT HU-D table: differences were 8.0% ± 5.7%, 10.9% ± 6.8% and 14.5% ± 10.4% respectively for pelvis, thorax and head patients using clinical treatment plans. The use of patient and group based HU-D tables resulted in small dose differences between planning CT and CBCT: 0.9% ± 0.9%, 1.8% ± 1.6%, 1.5% ± 2.5% for pelvis, thorax and head patients, respectively. The application of the phantom based HU-D table was acceptable for the head patients but larger deviations were determined for the pelvis and thorax patient populations.
The generation of three HU-D tables specific for the anatomical regions pelvis, thorax and head and specific for the corresponding CBCT image acquisition parameters resulted in accurate dose calculation in CBCT images. Once these HU-D tables are created, direct dose calculation on CBCT datasets is possible without the need of a reference CT images for pixel value calibration.
PMCID: PMC2648965  PMID: 19087250
7.  Gait in Pregnancy-related Pelvic girdle Pain: amplitudes, timing, and coordination of horizontal trunk rotations 
European Spine Journal  2008;17(9):1160-1169.
Walking is impaired in Pregnancy-related Pelvic girdle Pain (PPP). Walking velocity is reduced, and in postpartum PPP relative phase between horizontal pelvis and thorax rotations was found to be lower at higher velocities, and rotational amplitudes tended to be larger. While attempting to confirm these findings for PPP during pregnancy, we wanted to identify underlying mechanisms. We compared gait kinematics of 12 healthy pregnant women and 12 pregnant women with PPP, focusing on the amplitudes of transverse segmental rotations, the timing and relative phase of these rotations, and the amplitude of spinal rotations. In PPP during pregnancy walking velocity was lower than in controls, and negatively correlated with fear of movement. While patients’ rotational amplitudes were larger, with large inter-individual differences, spinal rotations did not differ between groups. In the patients, peak thorax rotation occurred earlier in the stride cycle at higher velocities, and relative phase was lower. The earlier results on postpartum PPP were confirmed for PPP during pregnancy. Spinal rotations remained unaffected, while at higher velocities the peak of thorax rotations occurred earlier in the stride cycle. The latter change may serve to avoid excessive spine rotations caused by the larger segmental rotations.
PMCID: PMC2527418  PMID: 18661160
Pregnancy-related Pelvic girdle Pain; Gait kinematics; Transverse rotation; Trunk coordination; Relative phase
8.  Lumbar Corsets Can Decrease Lumbar Motion in Golf Swing 
Swinging a golf club includes the rotation and extension of the lumbar spine. Golf-related low back pain has been associated with degeneration of the lumbar facet and intervertebral discs, and with spondylolysis. Reflective markers were placed directly onto the skin of 11young male amateur golfers without a previous history of back pain. Using a VICON system (Oxford Metrics, U.K.), full golf swings were monitored without a corset (WOC), with a soft corset (SC), and with a hard corset (HC), with each subject taking 3 swings. Changes in the angle between the pelvis and the thorax (maximum range of motion and angular velocity) in 3 dimensions (lumbar rotation, flexion-extension, and lateral tilt) were analyzed, as was rotation of the hip joint. Peak changes in lumbar extension and rotation occurred just after impact with the ball. The extension angle of the lumbar spine at finish was significantly lower under SC (38°) or HC (28°) than under WOC (44°) conditions (p < 0.05). The maximum angular velocity after impact was significantly smaller under HC (94°/sec) than under SC (177°/sec) and WOC (191° /sec) conditions, as were the lumbar rotation angles at top and finish. In contrast, right hip rotation angles at top showed a compensatory increase under HC conditions. Wearing a lumbar corset while swinging a golf club can effectively decrease lumbar extension and rotation angles from impact until the end of the swing. These effects were significantly enhanced while wearing an HC.
Key pointsRotational and extension forces on the lumbar spine may cause golf-related low back painWearing lumbar corsets during a golf swing can effectively decrease lumbar extension and rotation angles and angular velocity.Wearing lumbar corsets increased the rotational motion of the hip joint while reducing the rotation of the lumbar spine.
PMCID: PMC3761778  PMID: 24149729
Golf; back pain; motion analysis; orthosis; corset
9.  Biomechanical analysis of the spino-pelvic organization and adaptation in pathology 
European Spine Journal  2011;20(Suppl 5):609-618.
Standing in an erect position is a human property. The pelvis anatomy and position, defined by the pelvis incidence, interact with the spinal organization in shape and position to regulate the sagittal balance between both the spine and pelvis. Sagittal balance of the human body may be defined by a setting of different parameters such as (a) pelvic parameters: pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS); (b) C7 positioning: spino-pelvic angle (SSA) and C7 plumb line; (c) shape of the spine: lumbar lordosis.
Biomechanical adaptation of the spine in pathology
In case of pathological kyphosis, different mechanical compensations may be activated. When the spine remains flexible, the hyperextension of the spine below or above compensates the kyphosis. When the spine is rigid, the only way is rotating backward the pelvis (retroversion). This mechanism is limited by the value of PI. Hip extension is a limitation factor of big retroversion when PI is high. Flexion of the knees may occur when hip extension is overpassed. The quantity of global kyphosis may be calculated by the SSA. The more SSA decreases, the more the severity of kyphosis increases. We used Roussouly’s classification of lumbar lordosis into four types to define the shape of the spine. The forces acting on a spinal unit are combined in a contact force (CF). CF is the addition of gravity and muscle forces. In case of unbalance, CF is tremendously increased. Distribution of CF depends on the vertebral plate orientation. In an average tilt (45°), the two resultants, parallel to the plate (sliding force) or perpendicular (pressure), are equivalent. If the tilt increases, the sliding force is predominant. On the contrary, with a horizontal plate, the pressure increases. Importance of curvature is another factor of CF distribution. In a flat or kyphosis spine, CF acts more on the vertebral bodies and disc. In the case of important extension curvature, it is on the posterior elements that CF acts more. According to the shape of the spine, we may expect different degenerative evolution: (a) Type 1 is a long thoraco-lumbar kyphosis and a short hyperlordosis: discopathies in the TL area and arthritis of the posterior facets in the distal lumbar spine. In younger patients, L4 S1 hyperextension may induce a nutcracker L5 spondylolysis. (b) Type 2 is a flat lordosis: Stress is at its maximum on the discs with a high risk of early disc herniation than later with multilevel discopathies. (c) Type 3 has an average shape without characteristics for a specific degeneration of the spine. (d) Type 4 is a long and curved lumbar spine: this is the spine for L5 isthmic lysis by shear forces. When the patient keeps the lordosis curvature, a posterior arthritis may occur and later a degenerative L4 L5 spondylolisthesis. Older patients may lose the lordosis curvature, SSA decreases and pelvis tilt increases. A widely retroverted pelvis with a high pelvic incidence is certainly a previous Type 4 and a restoration of a big lordosis is needed in case of arthrodesis.
The genuine shape of the spine is probably one of the main mechanical factors of degenerative evolution. This shape is oriented by a shape pelvis parameter, the pelvis incidence. In case of pathology, this constant parameter is the only signature to determine the original spine shape we have to restore the balance of the patient.
PMCID: PMC3175914  PMID: 21809016
Lumbar lordosis; Spino-sacral angle; Thoracic kyphosis; Pelvic incidence; Pelvic tilt; Sacral slope; Sagittal balance; Pathological balance
10.  Effects of chronic low back pain on trunk coordination and back muscle activity during walking: changes in motor control 
European Spine Journal  2005;15(1):23-40.
Low back pain (LBP) is often accompanied by changes in gait, such as a decreased (preferred) walking velocity. Previous studies have shown that LBP diminishes the normal velocity-induced transverse counter-rotation between thorax and pelvis, and that it globally affects mean erector spinae (ES) activity. The exact nature and causation of these effects, however, are not well understood. The aim of the present study was to examine in detail the effect of walking velocity on global trunk coordination and ES activity as well as their variability to gain further insights into the effects of non-specific LBP on gait. The study included 19 individuals with non-specific LBP and 14 healthy controls. Gait kinematics and ES activity were recorded during treadmill walking at (1) a self-selected (comfortable) velocity, and (2) sequentially increased velocities from 1.4 up to maximally 7.0 km/h. Pain intensity, fear of movement and disability were measured before the experiment. The angular movements of thorax, lumbar and pelvis were recorded in three dimensions. ES activity was recorded with pairs of surface electrodes. Trunk–pelvis coordination and mean amplitude of ES activity were analyzed. In addition, invariant and variant properties of trunk kinematics and ES activity were studied using principal component analysis (PCA). Comfortable walking velocity was significantly lower in the LBP participants. In the transverse plane, the normal velocity-induced change in pelvis–thorax coordination from more in-phase to more antiphase was diminished in the LBP participants, while lumbar and pelvis rotations were more in-phase compared to the control group. In the frontal plane, intersegmental timing was more variable in the LBP than in the control participants, with additional irregular movements of the thorax. Rotational amplitudes were not significantly different between the LBP and control participants. In the LBP participants, the pattern of ES activity was affected in terms of increased (residual) variability, timing deficits, amplitude modifications and frequency changes. The gait of the LBP participants was characterized by a more rigid and less variable kinematic coordination in the transverse plane, and a less tight and more variable coordination in the frontal plane, accompanied by poorly coordinated activity of the lumbar ES. Pain intensity, fear of movement and disability were all unrelated to the observed changes in coordination, suggesting that the observed changes in trunk coordination and ES activity were a direct consequence of LBP per se. Clinically, the results imply that conservative therapy should consider gait training as well as exercises aimed at improving both intersegmental and muscle coordination.
PMCID: PMC3454567  PMID: 15864670
Chronic low back pain; Walking; Trunk coordination; Muscle coordination; Variability
11.  Conservative chiropractic management of urinary incontinence using applied kinesiology: a retrospective case-series report 
The purpose of this case series is to describe the chiropractic management of 21 patients with daily stress and occasional total urinary incontinence (UI).
Clinical Features
Twenty-one case files of patients 13 to 90 years of age with UI from a chiropractic clinic were reviewed. The patients had a 4-month to 49-year history of UI and associated muscle dysfunction and low back and/or pelvic pain. Eighteen wore an incontinence pad throughout the day and night at the time of their appointments because of unpredictable UI.
Intervention and Outcome
Patients were evaluated for muscle impairments in the lumbar spine, pelvis, and pelvic floor and low back and/or hip pain. Positive manual muscle test results of the pelvis, lumbar spine muscles, and pelvic floor muscles were the most common findings. Lumbosacral dysfunction was found in 13 of the cases with pain provocation tests (applied kinesiology sensorimotor challenge); in 8 cases, this sensorimotor challenge was absent. Chiropractic manipulative therapy and soft tissue treatment addressed the soft tissue and articular dysfunctions. Chiropractic manipulative therapy involved high-velocity, low-amplitude manipulation; Cox flexion distraction manipulation; and/or use of a percussion instrument for the treatment of myofascial trigger points. Urinary incontinence symptoms resolved in 10 patients, considerably improved in 7 cases, and slightly improved in 4 cases. Periodic follow-up examinations for the past 6 years, and no less than 2 years, indicate that for each participant in this case-series report, the improvements of UI remained stable.
The patients reported in this retrospective case series showed improvement in UI symptoms that persisted over time.
PMCID: PMC3315873  PMID: 22942842
Urinary incontinence; Pelvic floor; Manipulation, Chiropractic; Kinesiology, applied
12.  Development of upper body coordination during sitting in typically developing infants 
Pediatric research  2009;65(5):553-558.
Pediatric Research Articles Ahead of Print
contains articles in unedited manuscript form that have been peer-reviewed and accepted for publication. As a service to our readers, we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting and review of the resulting proof before it is published in its final definitive form. Please note that during the production process errors may be discovered, which could affect the content, and all legal disclaimers that apply to the journal pertain.
Our goal was to determine how the actions of the thorax and the pelvis are organized and coordinated to achieve independent sitting posture in typically developing infants. The participants were ten typically developing infants that were evaluated longitudinally from first onset of sitting until sitting independence. Each infant underwent nine testing sessions. The first session included motor evaluation with the Peabody test. The other eight sessions occurred over a period of four months where sitting behavior was evaluated by angular kinematics of the thorax and the pelvis. A physical therapist evaluated sitting behavior in each session and categorized it according to five stages. The phasing relationship of the thorax and the pelvis was calculated and evaluated longitudinally using a one-way ANOVA. With development, the infants progressed from an in-phase (moving in the same direction) to an out-of-phase (moving in an opposite direction) coordinative relationship between the thorax and the pelvis segments. This change was significant for both the sagittal and frontal planes of motion. Clinically, this relationship is important because it provides a method to quantify infant sitting postural development, and can be used to assess efficacy of early interventions for pediatric populations with developmental motor delays.
PMCID: PMC2713810  PMID: 19190546
13.  The Impact of Chiropractic Manipulative Therapy on Chronic Recurrent Lateral Ankle Sprain Syndrome in Two Young Athletes 
Journal of Chiropractic Medicine  2004;3(4):153-159.
To describe two cases of abrupt resolution of chronic, recurrent, inversion sprain to ankles in young recreational athletes.
Clinical Features
A 13-year-old, female, avid recreational soccer player with ankles that would spontaneously invert during various inconsistent points in the weight bearing gait cycle, sometimes with acute pain or sprain to the ankle. No intervention was attempted prior to her entry to the chiropractic office. A 17-year-old male avid skate- boarder and snowboarder whose left ankle routinely “gave out” into inversion upon mundane weight bearing activity, usually with pain and with dependence on wearing an ankle support when skateboarding to lessen ankle pain. The patient had used an ankle support prior to seeking chiropractic care.
Intervention and Outcome
High velocity, low amplitude chiropractic manipulative therapy applied to the spine, pelvis and extremity joints was the primary intervention in both cases, with particular focus on the ankle. Other procedures used included taping and orthotics, but not before the manipulation effect was noted.
High velocity, low amplitude chiropractic manipulative therapy to the spine, pelvis, and extremities, particularly at the ankle, should be considered when managing young recreational athletes with functional chronic, recurrent, ankle inversion sprains.
PMCID: PMC2647025  PMID: 19674638
Ankle Injuries; Sprains and Strains; Joint Instability; Chiropractic Manipulation; Lower Extremity
14.  Evolution of thorax architecture in ant castes highlights trade-off between flight and ground behaviors 
eLife  2014;3:e01539.
The concerted evolution of morphological and behavioral specializations has compelling examples in ant castes. Unique to ants is a marked divergence between winged queens and wingless workers, but morphological specializations for behaviors on the ground have been overlooked. We analyzed thorax morphology of queens and workers in species from 21 of the 25 ant subfamilies. We uncovered unique skeletomuscular modifications in workers that presumably increase power and flexibility of head–thorax articulation, emphasizing that workers are not simply wingless versions of queens. We also identified two distinct types of queens and showed repeated evolutionary associations with strategies of colony foundation. Solitary founding queens that hunt have a more worker-like thorax. Our results reveal that ants invest in the relative size of thorax segments according to their tasks. Versatility of head movements allows for better manipulation of food and objects, which arguably contributed to the ants’ ecological and evolutionary success.
eLife digest
The size and shape of an animal, known as its morphology, often reflect the actions it can perform. A grasshopper’s long legs, for example, are well suited to hopping, whilst the streamlined body of a dolphin helps swimming through water. These specialized features result from the interplay between morphology and behavior during evolution. A change in morphology can make new behaviors possible, which can then expose the animal to new environments and selective pressures that, in turn, can lead to further changes in morphology.
The interplay between morphology and behavior is particularly interesting in social insects such as ants. Queens and workers within an ant colony have a similar set of genes, but they have dramatically different morphologies and very different roles within the colony. Queens are responsible for reproduction, and are larger and have wings, which allow them to fly and establish a new colony away from where they were born. Workers are smaller and lack wings, and they devote themselves to building the nest, feeding the young larvae and protecting the colony. This marked morphological divergence, unique to ants, has fascinated researchers for more than a century. However, most studies have focused on the presence or absence of wings and have overlooked the interactions between morphology and the actions performed on the ground.
Like all insects, an ant’s body is divided into three parts: the head, the thorax (to which the legs and wings are attached), and the abdomen. Now, Keller et al. have examined the shape of the thorax in many species of ants and found that workers are not just smaller wingless versions of queens: rather, the architecture of their thorax is unique among species of flying insects. The front end of the worker thorax is greatly enlarged and is filled by strong neck muscles that power the head and its jaws, and allow workers to hunt and carry prey many times their own weight.
Keller et al. also identified two distinct types of queens and went on to show that these two shapes evolved in association with the two types of strategy that lone queens use to found new colonies. In species where queens convert their own wing muscles into the food for the first generation of workers, the wing muscles are much enlarged and the neck segment is extremely reduced. In species where queens hunt to feed the new colony, the wing and neck muscles are more balanced in size. As such, for those ant species where very little is known about how new colonies are founded, Keller et al. show that we can use the shape of the queen’s thorax to help predict this behavior.
Taken together, the results of Keller et al. show that female ants invest in the relative size of the different segments of the thorax in a way that reflects their behavior as adults. These adaptations partly explain why ants have been so extraordinarily successful in nature, and underscore the importance of carefully analyzing an organism’s form to fully understand its biology.
PMCID: PMC3881093  PMID: 24399458
ants; Formicidae; social insects; Other
15.  Helmet Fit and Cervical Spine Motion in Collegiate Men's Lacrosse Athletes Secured to a Spine Board 
Journal of Athletic Training  2010;45(3):215-221.
Proper management of cervical spine injuries in men's lacrosse players depends in part upon the ability of the helmet to immobilize the head.
To determine if properly and improperly fitted lacrosse helmets provide adequate stabilization of the head in the spine-boarded athlete.
Crossover study.
Sports medicine research laboratory.
Patients or Other Participants:
Eighteen healthy collegiate men's lacrosse players.
Participants were asked to move their heads through 3 planes of motion after being secured to a spine board under 3 helmet conditions.
Main Outcome Measure(s):
Change in range of motion in the cervical spine was calculated for the sagittal, frontal, and transverse planes for both head-to-thorax and helmet-to-thorax range of motion in all 3 helmet conditions (properly fitted, improperly fitted, and no helmet).
Head-to-thorax range of motion with the properly fitted and improperly fitted helmets was greater than in the no-helmet condition (P < .0001). In the sagittal plane, range of motion was greater with the improperly fitted helmet than with the properly fitted helmet. No difference was observed in helmet-to-thorax range of motion between properly and improperly fitted helmet conditions. Head-to-thorax range of motion was greater than helmet-to-thorax range of motion in all 3 planes (P < .0001).
Cervical spine motion was minimized the most in the no-helmet condition, indicating that in lacrosse players, unlike football players, the helmet may need to be removed before stabilization.
PMCID: PMC2865958  PMID: 20446833
stabilization; emergency management; protective equipment
16.  Protective and risk factors in amateur equestrians and description of injury patterns: A retrospective data analysis and a case - control survey 
In Switzerland there are about 150,000 equestrians. Horse related injuries, including head and spinal injuries, are frequently treated at our level I trauma centre.
To analyse injury patterns, protective factors, and risk factors related to horse riding, and to define groups of safer riders and those at greater risk
We present a retrospective and a case-control survey at conducted a tertiary trauma centre in Bern, Switzerland.
Injured equestrians from July 2000 - June 2006 were retrospectively classified by injury pattern and neurological symptoms. Injured equestrians from July-December 2008 were prospectively collected using a questionnaire with 17 variables. The same questionnaire was applied in non-injured controls. Multiple logistic regression was performed, and combined risk factors were calculated using inference trees.
Retrospective survey
A total of 528 injuries occured in 365 patients. The injury pattern revealed as follows: extremities (32%: upper 17%, lower 15%), head (24%), spine (14%), thorax (9%), face (9%), pelvis (7%) and abdomen (2%). Two injuries were fatal. One case resulted in quadriplegia, one in paraplegia.
Case-control survey
61 patients and 102 controls (patients: 72% female, 28% male; controls: 63% female, 37% male) were included. Falls were most frequent (65%), followed by horse kicks (19%) and horse bites (2%). Variables statistically significant for the controls were: Older age (p = 0.015), male gender (p = 0.04) and holding a diploma in horse riding (p = 0.004). Inference trees revealed typical groups less and more likely to suffer injury.
Experience with riding and having passed a diploma in horse riding seem to be protective factors. Educational levels and injury risk should be graded within an educational level-injury risk index.
PMCID: PMC3042925  PMID: 21294862
17.  Establishment of CT diagnostic reference levels in Ireland 
The British Journal of Radiology  2012;85(1018):1390-1397.
To propose Irish CT diagnostic reference levels (DRLs) by collecting radiation doses for the most commonly performed CT examinations.
A pilot study investigated the most frequent CT examinations. 40 CT sites were then asked to complete a survey booklet to allow the recording of CT parameters for each of 9 CT examinations during a 12-week period. Dose data [CT volume index (CTDIvol) and dose–length product (DLP)] on a minimum of 10 average-sized patients in each category were recorded to calculate a mean site CTDIvol and DLP value. The rounded 75th percentile was used to calculate a DRL for each site and the country by compiling all results. Results are compared with international DRL data.
Data were collected for 3305 patients. 30 sites responded with data for 34 scanners, representing 54% of the national total. All equipment had multislice capability (2–128 slices). DRLs are proposed using CTDIvol (mGy) and DLP (mGy cm) for CT head (66/58 and 940, respectively), sinuses (16 and 210, respectively), cervical spine (19 and 420, respectively), thorax (9/11 and 390, respectively), high resolution CT (7 and 280, respectively), CT pulmonary angiography (13 and 430, respectively), multiphase abdomen (13 and 1120, respectively), routine abdomen/pelvis (12 and 600, respectively) and trunk examinations (10/12 and 850, respectively). These values are lower than current DRLs and comparable to other international studies. Wide variations in mean doses are noted across sites.
Baseline figures for Irish CT DRLs are provided on the most frequently performed CT examinations. The variations in dose between CT departments as well as between identical scanners suggest a large potential for optimisation of examinations.
PMCID: PMC3474022  PMID: 22595497
18.  Primary Reasons for Osteopathic Consultation: A Prospective Survey in Quebec 
PLoS ONE  2014;9(9):e106259.
Osteopathy is an increasingly popular health care modality to address pain and function in the musculoskeletal system, organs and the head region, as well as functional somatic syndromes. Although osteopathy is recommended principally in guidelines for management of back pain, osteopaths' scope of practice is wide, albeit poorly defined. In order to understand better the practice of osteopathy, this study aimed to investigate the most common reasons for osteopathic consultations in clinical settings in Quebec.
A prospective survey of members of the Registre des ostéopathes du Québec was conducted to examine demographics in osteopathic practices, as well as patients' primary reasons for consultations over a two-week period. The questionnaire was devised following a literature review and refined and verified with two stages of expert input.
277 osteopaths (60.1% response rate) responded to the survey notice. 14,002 patients' primary reasons for consultations were reported in completed questionnaires and returned by practicing osteopaths. Musculoskeletal pain located in the spine, thorax, pelvis and limbs was the most common reason for consultations (61.9%), with females consulting most commonly for cervical pain and males for lumbar pain. Perinatal and paediatric (11.8%), head (9.1%), visceral (5.0%) and general concerns (4.8%) were the other most common reasons for consultations. Preventive care represented the remaining 0.3%.
The nature of primary reasons for osteopathic consultations, coupled with documented satisfaction of patients with this approach, suggest a future for multidisciplinary collaborative health care including osteopathy. Results of this survey may contribute to informing physicians and others pending regulation of Quebec osteopaths, and also provide direction for future clinical research and guidelines development.
PMCID: PMC4153609  PMID: 25184204
19.  Analysis of squat and stoop dynamic liftings: muscle forces and internal spinal loads 
European Spine Journal  2006;16(5):687-699.
Despite the well-recognized role of lifting in back injuries, the relative biomechanical merits of squat versus stoop lifting remain controversial. In vivo kinematics measurements and model studies are combined to estimate trunk muscle forces and internal spinal loads under dynamic squat and stoop lifts with and without load in hands. Measurements were performed on healthy subjects to collect segmental rotations during lifts needed as input data in subsequent model studies. The model accounted for nonlinear properties of the ligamentous spine, wrapping of thoracic extensor muscles to take curved paths in flexion and trunk dynamic characteristics (inertia and damping) while subject to measured kinematics and gravity/external loads. A dynamic kinematics-driven approach was employed accounting for the spinal synergy by simultaneous consideration of passive structures and muscle forces under given posture and loads. Results satisfied kinematics and dynamic equilibrium conditions at all levels and directions. Net moments, muscle forces at different levels, passive (muscle or ligamentous) forces and internal compression/shear forces were larger in stoop lifts than in squat ones. These were due to significantly larger thorax, lumbar and pelvis rotations in stoop lifts. For the relatively slow lifting tasks performed in this study with the lowering and lifting phases each lasting ∼2 s, the effect of inertia and damping was not, in general, important. Moreover, posterior shift in the position of the external load in stoop lift reaching the same lever arm with respect to the S1 as that in squat lift did not influence the conclusion of this study on the merits of squat lifts over stoop ones. Results, for the tasks considered, advocate squat lifting over stoop lifting as the technique of choice in reducing net moments, muscle forces and internal spinal loads (i.e., moment, compression and shear force).
PMCID: PMC2213554  PMID: 17103232
Muscle force; Finite element; Dynamic; Kinematics; Lifting technique
20.  Thorax, pelvis and hip pattern in the frontal plane during walking in unilateral transtibial amputees: biomechanical analysis 
Lower limb amputees exhibit postural control deficits during standing which can affect their walking ability.
The primary purpose of the present study was to analyze the thorax, pelvis, and hip kinematics and the hip internal moment in the frontal plane during gait in subjects with Unilateral Transtibial Amputation (UTA).
The participants included 25 people with UTA and 25 non-amputees as control subjects. Gait analysis was performed using the Vicon(r) Motion System. We analyzed the motion of the thorax, pelvis, and hip (kinematics) as well as the hip internal moment in the frontal plane.
The second peak of the hip abductor moment was significantly lower on the prosthetic side than on the sound side (p=.01) and the control side (right: p=.01; left: p=.01). During middle stance, the opposite side of the pelvis was higher on the prosthetic side compared to the control side (right: p=.01: left: p=.01).
The joint internal moment at the hip in the frontal plane was lower on the prosthetic side than on the sound side or the control side. Thorax and pelvis kinematics were altered during the stance phase on the prosthetic side, presumably because there are mechanisms which affect postural control during walking.
PMCID: PMC4183500  PMID: 25003278
unilateral transtibial amputation; physical therapy; joint moments; frontal plane; kinematics; pelvis motion
21.  Spinal and sacroiliac assessment and treatment techniques used by osteopathic physicians in the United States 
Osteopathic manipulative medicine texts and educators advocate a range of approaches for physical assessment and treatment, but little is known about their use by osteopathic physicians in the United States.
A web-based survey using a 5-point Likert scale was developed and e-mailed to 777 practicing osteopathic physician members of the American Academy of Osteopathy. Responses in the "frequently" and "always" categories were combined for reporting purposes. Friedman tests were used to analyze the reported usage of each item. The effect of gender was analyzed using Mann-Whitney tests.
One hundred seventy-one osteopathic physicians completed the survey (22%). For the assessment of spinal somatic dysfunction, paraspinal tissue texture (98%), transverse process asymmetry (89%), and tenderness (85%) were most commonly reported. Myofascial release (78%), soft tissue technique (77%), and patient self-stretches (71%) were most commonly used for treatment of the spine. For assessment of pelvic landmark asymmetry, the anterior superior iliac spine (ASIS, 87%), sacral base (82%), posterior superior iliac spine (81%), sacral sulci (78%), iliac crests (77%), and inferior lateral angle of the sacrum (74%) were commonly palpated. For assessment of sacroiliac joint motion, ASIS compression (68%) was most commonly used. Sacroiliac pain provocation tests were also employed although their use was less common than asymmetry or motion tests. Muscle energy (70%), myofascial release (67%), patient self-stretches (66%), osteopathy in the cranial field (59%), muscle strengthening exercises (58%), soft tissue technique (58%), and articulatory technique (53%) were most commonly used for treatment of the pelvis and sacroiliac. The effect of gender was significant for many of the treatment procedures, with females using more soft tissue and muscle energy and males more high-velocity techniques. The majority of respondents document the types of osteopathic manipulative techniques used (83%), document somatic dysfunction with Fryette nomenclature (64%), and bill for osteopathic manipulative treatment (92%).
Respondents reported the use of a broad range of assessment and treatment approaches. Results suggest a higher use of myofascial release and cranial technique and lower use of high-velocity techniques in this group of physicians compared to previous studies.
PMCID: PMC2676310  PMID: 19366458
22.  Reliability of Bony Anatomic Landmark Asymmetry Assessment in the Lumbopelvic Region: Application to Osteopathic Medical Education 
The objective of this review is to establish the current state of knowledge on the reliability of clinical assessment of asymmetry in the lumbar spine and pelvis. To search the literature, the authors consulted the databases of MEDLINE, CINAHL, AMED, MANTIS, Academic Search Complete, and Web of Knowledge using different combinations of the following keywords: palpation, asymmetry, inter- or intraex-aminer reliability, tissue texture, assessment, and anatomic landmark. Of the 23 studies identified, 14 did not meet the inclusion criteria and were excluded. The quality and methods of studies investigating the reliability of bony anatomic landmark asymmetry assessment are variable. The κ statistic ranges without training for interexaminer reliability were as follows: anterior superior iliac spine (ASIS), −0.01 to 0.19; posterior superior iliac spine (PSIS), 0.04 to 0.15; inferior lateral angle, transverse plane (ILA-A/P), −0.03 to 0.11; inferior lateral angles, coronal plane (ILA-S/I), −0.01 to 0.08; sacral sulcus (SS), −0.4 to 0.37; lumbar spine transverse processes L1 through L5, 0.04 to 0.17. The corresponding ranges for intraexaminer reliability were higher for all associated landmarks: ASIS, 0.19 to 0.4; PSIS, 0.13 to 0.49; ILA-A/P, 0.1 to 0.2; ILA-S/I, 0.03 to 0.21; SS, 0.24 to 0.28; lumbar spine transverse processes L1 through L5, not applicable. Further research is needed to better understand the reliability of asymmetry assessment methods in manipulative medicine.
PMCID: PMC3124075  PMID: 21135198
23.  Intracerebral bullet removal through an endoscopic transnasal craniectomy 
In the past decade, the endoscopic transnasal technique has been broadly applied as a feasible and less invasive approach to the skull base. The adaptability of the endoscopic technique allows a case-specific approach in order to minimize both endonasal and cranio-cerebral manipulation; therefore it can be also used in patients complaining exceptional skull base lesions and in weak patients. The objective of this paper is to present the first case of intracerebral bullet removal using a pure endoscopic transnasal route through a custom made unilateral craniectomy.
Case Description:
A 59-year-old patient was admitted to the emergency department after a gunshot injury to the head, thorax, abdomen, and pelvis. Admission Glasgow Coma Scale was 7. Brain computed tomography (CT) scan highlighted a right occipital hole defect due to perforative impact, intracerebral dislocations of bone fragments, right intracerebral and subdural hematoma, and midline shift to the left side; the bullet was localized in the right frontal lobe and its tip was in contact with the ethmoid roof.
The patient underwent emergency decompressive craniectomy and evacuation of the subdural hematoma and abdominal explorative laparotomy, ileum resection, and gastrorrhaphy. After 1 month, the patient underwent endoscopic transnasal removal of the bullet and skull base reconstruction due to cerebrospinal fluid infection. The postoperative course was uneventful and he has done well in follow-up with no evidence of cerebrospinal fluid leak and preservation of olfaction.
The adaptability of the endoscopic transnasal technique offers patients complaining exceptional skull base lesions a case-specific strategy minimizing morbidity and postoperative stay.
PMCID: PMC3551493  PMID: 23372971
Bullet removal; endoscopic; intracerebral; transnasal
24.  Precision of estimates of local stability of repetitive trunk movements 
European Spine Journal  2013;22(12):2678-2685.
Local dynamic stability of trunk movements quantified by means of the maximum Lyapunov exponent (λmax) can provide information on trunk motor control and might offer a measure of trunk control in low-back pain patients. It is unknown how many repetitions are necessary to obtain sufficiently precise estimates of λmax and whether fatigue effects on λmax can be avoided while increasing the number of repetitions.
Ten healthy subjects performed 100 repetitions of trunk movements in flexion, of trunk rotation and of a task combining these movement directions. λmax was calculated from thorax, pelvis and trunk (thorax relative to pelvis) kinematics. Data series were analyzed using a bootstrap procedure; ICC and coefficient of variation were used to quantify precision as a function of the number of cycles analyzed. ANOVA was used to compare movement tasks and to test for effects of time.
Trunk local stability reached acceptable precision level after 30 repetitions. λmax was higher (indicating lower stability) in flexion, compared to rotation and combined tasks. There was no time effect (fatigue). λmax of trunk movement was lower and less variable than that of thorax and pelvis movements.
The data provided allow for an informed choice of the number of repetitions in assessing local dynamic stability of trunk movements, weighting the gain in precision against the increase in measurement effort. Within the 100 repetitions tested, fatigue did not affect results. We suggest that increased stability during asymmetric movement may be explained by higher co-activation of trunk muscles.
PMCID: PMC3843800  PMID: 23653131
Trunk; Spinal stability; Lyapunov exponent; Statistical precision
25.  Effects of attention on the control of locomotion in individuals with chronic low back pain 
People who suffer from low back pain (LBP) exhibit an abnormal gait pattern, characterized by shorter stride length, greater step width, and an impaired thorax-pelvis coordination which may undermine functional walking. As a result, gait in LBP may require stronger cognitive regulation compared to pain free subjects thereby affecting the degree of automaticity of gait control. Conversely, because chronic pain has a strong attentional component, diverting attention away from the pain might facilitate a more efficient walking pattern.
Twelve individuals with LBP and fourteen controls participated. Subjects walked on a treadmill at comfortable speed, under varying conditions of attentional load: (a) no secondary task, (b) naming the colors of squares on a screen, (c) naming the colors of color words ("color Stroop task"), and (d) naming the colors of words depicting motor activities. Markers were attached to the thorax, pelvis and feet. Motion was recorded using a three-camera SIMI system with a sample frequency of 100 Hz. To examine the effects of health status and attention on gait, mean and variability of stride parameters were calculated. The coordination between thoracic and pelvic rotations was quantified through the mean and variability of the relative phase between those oscillations.
LBP sufferers had a lower walking speed, and consequently a smaller stride length and lower mean thorax-pelvis relative phase. Stride length variability was significantly lower in the LBP group but no significant effect of attention was observed. In both groups gait adaptations were found under performance of an attention demanding task, but significantly more so in individuals with LBP as indicated by an interaction effect on relative phase variability.
Gait in LBP sufferers was characterized by less variable upper body movements. The diminished flexibility in trunk coordination was aggravated under the influence of an attention demanding task. This provides further evidence that individuals with LBP tighten their gait control, and this suggests a stronger cognitive regulation of gait coordination in LBP. These changes in gait coordination reduce the capability to deal with unexpected perturbations, and are therefore maladaptive.
PMCID: PMC2387160  PMID: 18439264

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