Over years it has been increasingly concerned with how upper extremity musculoskeletal disorders (UEMSDs) are attributed to psychosocial job stressors. A review study was conducted to examine associations between UEMSDs and psychosocial work factors, and to recommend what to consider for the associations. For studies in which the job demand-control-support (DCS) model or its variables were specifically employed, published papers were selected and reviewed. A number of studies have reported relationships between UEMSDs symptoms and psychosocial exposure variables. For example, the findings are: higher numbness in the upper extremity was significantly attributed to by less decision latitude at work; work demands were significantly associated with neck and shoulder symptoms while control over time was associated with neck symptoms; and the combination of high psychosocial demands and low decision latitude was a significant predictor for shoulder and neck pain in a female working population. Sources of bias, such as interaction or study design, were discussed. UEMSDs were shown to be associated with psychosocial work factors in various studies where the job DCS model was addressed. Nonetheless, this review suggests that further studies should be conducted to much more clarify the association between UEMSDs and psychosocial factors.
Upper extremity musculoskeletal disorders; Psychosocial work factors; Job DCS model
Previous work has shown an association between restricted wrist range of motion (ROM) and upper extremity musculoskeletal disorders in computer users. We compared the prevalence of MRI-identified wrist abnormalities and wrist ROM between asymptomatic and symptomatic computer users.
MR images at 1.5 T of both wrists were obtained from 10 asymptomatic controls (8 F, 2 M) and 14 computer users (10 F, 4 M) with chronic wrist pain (10 bilateral; 4 right-side). Maximum wrist range of motion in flexion and radioulnar deviation was measured with an electrogoniometer.
Extraosseous ganglia were identified in 66.6% of asymptomatic wrists and in 75% of symptomatic wrists. Intraosseous ganglia were identified in 45.8% of asymptomatic wrists and in 75% of symptomatic wrists, and were significantly (p < .05) larger in the symptomatic wrists. Distal ECU tendon instability was identified in 58.4% of both asymptomatic and symptomatic wrists. Dominant wrist flexion was significantly greater in the asymptomatic group (68.8 ± 6.7 deg.) compared to the symptomatic group (60.7 ± 7.3 deg.), p < .01. There was no significant correlation between wrist flexion and intraosseous ganglion burden (p = .09)
This appears to be the first MRI study of wrist abnormalities in computer users.
This study demonstrates that a variety of wrist abnormalities are common in computer users and that only intraosseous ganglia prevalence and size differed between asymptomatic and symptomatic wrists. Flexion was restricted in the dominant wrist of the symptomatic group, but the correlation between wrist flexion and intraosseous ganglion burden did not reach significance. Flexion restriction may be an indicator of increased joint loading, and identifying the cause may help to guide preventive and therapeutic interventions.
A longitudinal cohort of automobile manufacturing workers (n = 1214) was examined for: 1) prevalence and persistence of specific upper extremity musculoskeletal disorders (UEMSDs) such as lateral epicondylitis and de Quervain's disease, and non-specific disorders (NSDs) defined in symptomatic individuals without any specific disorder, and 2) disorder prognoses based on symptom characteristics and other factors.
Eight specific disorders were identified through case definitions based on upper extremity physical examinations and symptom surveys administered on three occasions over six years.
At baseline, 41% of the cohort reported upper extremity symptoms; 18% (n = 214) of these had NSDs. In each survey, tendon-related conditions accounted for over half of the specific morbidity. Twenty-five percent had UEMSDs in multiple anatomical sites, and most with hand/wrist disorders had two or more hand/wrist UEMSDs. Persistence for all specific disorders decreased with length of follow-up. Specific UEMSDs were characterized by greater pain severity and functional impairment, and more lost work days than NSDs.
Upper extremity symptoms and diagnoses vary over time. NSDs may be the early stages of conditions that will eventually become more specific. NSDs and overlapping specific UEMSDs should be taken into account in UEMSD classification.
To examine the hypothesis that forearm pain with palpation tenderness in computer users is associated with increased extensor muscle fatigue.
Eighteen persons with pain and moderate to severe palpation tenderness in the extensor muscle group of the right forearm and twenty gender and age matched referents without such complaints were enrolled from the Danish NUDATA study of neck and upper extremity disorders among technical assistants and machine technicians. Fatigue of the right forearm extensor muscles was assessed by muscle twitch forces in response to low frequency (2 Hz) percutaneous electrical stimulation. Twitch forces were measured before, immediately after and 15 minutes into recovery of an extensor isometric wrist extension for ten minutes at 15 % Maximal Voluntary Contraction (MVC).
The average MVC wrist extension force and baseline stimulated twitch forces were equal in the case and the referent group. After the fatiguing contraction, a decrease in muscle average twitch force was seen in both groups, but the decrease was largest in the referent group: 27% (95% CI 17–37) versus 9% (95% CI -2 to 20). This difference in twitch force response was not explained by differences in the MVC or body mass index.
Computer users with forearm pain and moderate to severe palpation tenderness had diminished forearm extensor muscle fatigue response. Additional studies are necessary to determine whether this result reflects an adaptive response to exposure without any pathophysiological significance, or represents a part of a causal pathway leading to pain.
Obstetrical brachial plexus paralysis (OBPP) is a complex, multifaceted disorder with potentially disabling sequalae. Although the shoulder is the most frequently affected joint, the forearm, wrist, and hand may also display diabling deformities. In sequalae involving the forearm, the most frequent deformity is supination contractures followed by pronation contractures. Treatment of OBPP has recently focused on early microsurgical repair; nonetheless, palliative surgery still plays a critical role in the overall reconstructive planning in order to diminish the sequalae of OBPP and improve function of the upper extremity. The preferred palliative surgical proceures for the forearm and hand include flexor or extensor tendon transfers, free muscle transfers, opponensplasty, and bone fusion. The most commonly restored functions are elbow flexion and extension, finger flexion and extension, and, in some cases, shoulder abduction and intrinsic substitution.
Obstetrical paralysis; supination deformity; ulnar deviation; wrist drop
The study aimed to assess the relative importance of personal and occupational risk factors for upper-extremity musculoskeletal disorders (UEMSDs) in the working population.
A total of 3,710 workers (58% of men) participating in a surveillance program of MSDs in a French region in 2002–2005 were included. UEMSDs were diagnosed by 83 trained occupational physicians performing a standardized physical examination. Personal factors and work exposure were assessed by a self-administered questionnaire. Statistical associations between MSDs, personal and occupational factors were analyzed using logistic regression modeling.
A total of 472 workers suffered from at least one UEMSD. The risk of UEMSDs increased with age for both genders (P<0.001) (O.R. up to 4.9 in men and 5.0 and in women) and in cases of prior history of UEMSDs (OR 3.1 and 5.0, P<0.001). In men, UEMSDs were associated with obesity (OR 2.2, P=0.014), high level of physical demand (OR 2.0, P<0.001), high repetitiveness of the task (OR 1.5, P=0.027), postures with the arms at or above shoulder level (OR 1.7, P=0.009) or with full elbow flexion (OR 1.6, P=0.006), and high psychological demand (O.R. 1.5, P=0.005). In women, UEMSDs were associated with diabetes mellitus (O.R. 4.9, P=0.001), postures with extreme wrist bending (OR 2.0, P<0.001), use of vibrating hand tools (O.R. 2.2, P=0.025) and low level of decision authority (OR 1.4, P=0.042).
The study showed that personal and work-related physical and psychosocial factors were strongly associated with clinically-diagnosed UEMSDs.
Musculoskeletal disorders; upper extremity; risk factors; personal factors; physical exposure; psychosocial factors; work; Adult; Employment; Female; Humans; Male; Middle Aged; Musculoskeletal Diseases; diagnosis; epidemiology; etiology; Occupational Diseases; diagnosis; epidemiology; etiology; Risk Factors; Safety Management; Upper Extremity; pathology; physiopathology
Few prospective studies have evaluated outcomes of workers with self-reported symptoms of upper extremity musculoskeletal disorders (UEMSD). Our objective was to study the three-year outcomes of workers with self-reported symptoms, with or without a positive physical examination.
In 1993–1994, 598 subjects highly exposed to repetitive work filled out a Nordic-style questionnaire. They underwent a standardised physical examination at that time and again in 1996–1997 by the same occupational physician. The three-year outcomes (based on physical examination) of workers with a self-administered questionnaire positive at baseline for UEMSD, with or without a positive physical examination, were studied.
The three-year incidence rate was 44.1%, with one third of these incident cases who had self-reported symptoms in 1993–1994. Workers with a positive questionnaire had a significantly higher risk of UEMSD at physical examination three year later (80.1% UEMSD cases with positive questionnaires n=354, versus 44.2% cases without positive questionnaires n=69, p<0.0001). Moreover, workers with positive questionnaires but without UEMSD diagnosed in 1993–1994 (n=177) had also a significantly higher risk of UEMSD at physical examination three years later (60.5% cases with positive questionnaires n=26, versus 38.8% cases without positive questionnaires n=52, p=0.01). Results were similar when gender and age were taken into account.
Workers highly exposed to repetitive movements had a high risk of developing UEMSD and should be followed closely in surveillance programmes. Workers with self-reported symptoms without UEMSD diagnosed in physical examination represented only one third of new cases three years later. However, their risk to develop UEMSD was significantly increased, compared with those without symptoms.
This review examines the evidence for an association between computer work and neck and upper extremity disorders (except carpal tunnel syndrome).
A systematic critical review of studies of computer work and musculoskeletal disorders verified by a physical examination was performed.
A total of 22 studies (26 articles) fulfilled the inclusion criteria. Results show limited evidence for a causal relationship between computer work per se, computer mouse and keyboard time related to a diagnosis of wrist tendonitis, and for an association between computer mouse time and forearm disorders. Limited evidence was also found for a causal relationship between computer work per se and computer mouse time related to tension neck syndrome, but the evidence for keyboard time was insufficient. Insufficient evidence was found for an association between other musculoskeletal diagnoses of the neck and upper extremities, including shoulder tendonitis and epicondylitis, and any aspect of computer work.
There is limited epidemiological evidence for an association between aspects of computer work and some of the clinical diagnoses studied. None of the evidence was considered as moderate or strong and there is a need for more and better documentation.
Hammering is a functional task in which the wrist generally follows a path of motion from a position of combined radial deviation and extension to combined ulnar deviation and flexion, colloquially referred to as a dart thrower's motion (DTM). The purpose of this study was to measure wrist and forearm motion and scaphoid and lunate kinematics during a simulated hammering task. We hypothesized that the wrist follows an oblique path from radial extension to ulnar flexion and that there would be minimal radiocarpal motion during the hammering task.
13 healthy volunteers consented to have their wrist and distal forearm imaged with computed tomography at five positions in a simulated hammering task. The kinematics of the carpus and distal radial ulnar joint were calculated using established markerless bone registration methods. The path of wrist motion was described relative to the sagittal plane. Forearm rotation and radioscaphoid and radiolunate motion were computed as a function wrist position.
All volunteers performed the simulated hammering task using a path of wrist motion from radial extension to ulnar flexion that was oriented an average 41 ± 3° from the sagittal plane. These paths did not pass through the anatomic neutral wrist position; rather they passed through the neutral hammering position, which was offset by 36° ± 8° in extension. Rotations of the scaphoid and lunate were not minimal but averaged 40% and 41% respectively of total wrist motion. The range of forearm pronosupination during the task averaged 12 ± 8°.
The simulated hammering task was performed using a wrist motion that followed an oblique path, from radial extension to ulnar flexion. Scaphoid and lunate rotations were significantly reduced, but not minimized, when compared with rotations during pure wrist flexion/extension. This is likely due to the fact that an extended wrist position was maintained throughout the entire task studied.
Carpal; Kinematics; Hammering; Scaphoid; Lunate
Aspects of afferent inputs, generally termed proprioception, are being increasingly studied. Extraneous factors such as cutaneous inputs can dramatically interfere while trying to design studies in order to determine the participation of the different structures involved in proprioception in the wrist position sense. We tried to determine validity and repeatability of a new wrist joint position measurement device using methodology designed to minimize extraneous factors and isolate muscle and joint inputs.
In order to test the reliability of the system, eighty young-adult subjects without musculoskeletal or neurologic impairments affecting the right upper extremity were tested using a custom made motion tracking system. Testing consisted of two conditions: active reproduction of active placement and passive reproduction of passive placement. Subjects performed two repetitions of each target position (10, 20, and 30° of flexion and extension) presented in a random order. Test- retest reliability was then tested.
The average constant error in the passive condition was -0.7° ± 4.7° as compared to the active condition at 3.7° ± 5.1°. Average absolute error in the passive condition was 4.9° ± 2.9° compared to the active condition in which absolute error was 5.9° ± 3.5°.
Test-retest repeatability in both conditions was less than the 5° magnitude typical of clinical goniometry. Errors in the active condition (less than 2°) were slightly smaller than the passive condition, and the passive condition was also associated with poorer consistency between apparatus sensors and skin sensors.
The current system for measurement of wrist joint proprioception allows the researcher to decrease extraneous influences that may affect joint position sense awareness, and will help in future study aiming to determine precisely the role of the different structure involved in proprioception.
OBJECTIVE: To evaluate the association between upper extremity soft tissue disorders and exposure to preventable ergonomic stressors in vehicle manufacturing operations. METHODS: A cross sectional study was conducted in one vehicle stamping plant and one engine assembly plant. A standardised physical examination of the upper extremities was performed on all subjects. An interviewer administered questionnaire obtained data on demographics, work history, musculoskeletal symptoms, non-occupational covariates, and psycho-physical (relative intensity) ratings of ergonomic stressors. The primary exposure score was computed by summing the responses to the psychophysical exposure items. Multivariate regression analysis was used to model the prevalence of disorders of the shoulders or upper arms, wrists or hands, and all upper extremity regions (each defined both by symptoms and by physical examination plus symptoms) as a function of exposure quartile. RESULTS: A total of 1315 workers (85% of the target population) was examined. The prevalence of symptom disorders was 22% for the wrists or hands and 15% for the shoulders or upper arms; cases defined on the basis of a physical examination were about 80% as frequent. Disorders of the upper extremities, shoulders, and wrists or hands all increased markedly with exposure score, after adjustment for plant, acute injury, sex, body mass index, systemic disease, and seniority. CONCLUSIONS: Musculoskeletal disorders of the upper extremities were strongly associated with exposure to combined ergonomic stressors. The exposure- response trend was very similar for symptom cases and for physical examination cases. It is important to evaluate all dimensions of ergonomic exposure in epidemiological studies, as exposures often occur in combination in actual workplaces.
There is increasing attention to medical problems of musicians. Many studies find a high prevalence of work-related musculoskeletal disorders in musicians, ranging from 73.4% to 87.7%, and string players have the highest prevalence of musculoskeletal problems. This paper examines the various positions and movements of the upper extremities in string players: 1) basic postures for holding instruments, 2) movements of left upper extremity: fingering, forearm posture, high position and vibrato, 3) movements of right upper extremity: bowing, bow angles, pizzicato and other bowing techniques. These isotonic and isometric movements can lead to musculoskeletal problems in musicians. We reviewed orthopedic disorders that are specific to string players: overuse syndrome, muscle-tendon syndrome, focal dystonia, hypermobility syndrome, and compressive neuropathy. Symptoms, interrelationships with musical performances, diagnosis and treatment of these problems were then discussed.
Upper extremities; String players; Musculoskeletal problems
To summarize systematic reviews that 1) assessed the evidence for causal relationships between computer work and the occurrence of carpal tunnel syndrome (CTS) or upper extremity musculoskeletal disorders (UEMSDs), or 2) reported on intervention studies among computer users/or office workers.
PubMed, Embase, CINAHL and Web of Science were searched for reviews published between 1999 and 2010. Additional publications were provided by content area experts. The primary author extracted all data using a purpose-built form, while two of the authors evaluated the quality of the reviews using recommended standard criteria from AMSTAR; disagreements were resolved by discussion. The quality of evidence syntheses in the included reviews was assessed qualitatively for each outcome and for the interventions.
Altogether, 1,349 review titles were identified, 47 reviews were retrieved for full text relevance assessment, and 17 reviews were finally included as being relevant and of sufficient quality. The degrees of focus and rigorousness of these 17 reviews were highly variable. Three reviews on risk factors for carpal tunnel syndrome were rated moderate to high quality, 8 reviews on risk factors for UEMSDs ranged from low to moderate/high quality, and 6 reviews on intervention studies were of moderate to high quality. The quality of the evidence for computer use as a risk factor for CTS was insufficient, while the evidence for computer use and UEMSDs was moderate regarding pain complaints and limited for specific musculoskeletal disorders. From the reviews on intervention studies no strong evidence based recommendations could be given.
Computer use is associated with pain complaints, but it is still not very clear if this association is causal. The evidence for specific disorders or diseases is limited. No effective interventions have yet been documented.
Static trunk flexion working postures and disturbed trunk muscle reflexes are related to increased risk of low-back pain. Animal studies conclude that these factors may be related; passive tissue strain in spinal ligaments causes subsequent short-term changes in reflex. Although studies have documented changes in the myoelectric onset angle of flexion-relaxation following prolonged static flexion and cyclic flexion we could find no published evidence related to the human reflex response of the trunk extensor muscles following a period of static flexion-relaxation loading.
Eighteen subjects maintained static lumbar flexion for 15 min. Paraspinal muscle reflexes were elicited both before and after the flexion-relaxation protocol using pseudorandom stochastic force disturbances while recording EMG. Reflex gain was computed from the peak value of the impulse response function relating input force perturbation to EMG response using time-domain deconvolution analyses.
Reflexes showed a trend toward increased gain after the period of flexion-relaxation (P < 0.055) and were increased with trunk extension exertion (P < 0.021). Significant gender differences in reflex gain were observed (P < 0.01).
Occupational activities requiring extended periods of trunk flexion contribute to changes in reflex behavior of the paraspinal muscles. Results suggest potential mechanisms by which flexed posture work may contribute to low-back pain. Significant gender differences indicate risk analyses should consider personal factors when considering neuromuscular behavior.
Low-back; Reflex; Flexion-relaxation
Proprioception of hand orientation (orientation production using the hand) is compared with manual matching of visual orientation (visual surface matching using the hand) in two experiments. In Experiment 1, using self-selected arm postures, the proportions of wrist and elbow flexion spontaneously used to orient the pitch of the hand (20% and 80% respectively) are relatively similar across both manual matching tasks and manual orientation production tasks for most participants. Proprioceptive error closely matched perceptual biases previously reported for visual orientation perception, suggesting calibration of proprioception to visual biases. A minority of participants, who attempted to use primarily wrist flexion while holding the forearm horizontal, performed poorly at the manual matching task, consistent with proprioceptive error caused by biomechanical constraints of their self-selected posture. In Experiment 2, postural choices were constrained to primarily wrist or elbow flexion without imposing biomechanical constraints (using a raised forearm). Identical relative offsets were found between the two constraint groups in manual matching and manual orientation production. The results support two claims: (1) manual orientation matching to visual surfaces is based on manual proprioception and (2) calibration between visual and proprioceptive experiences guarantees relatively accurate manual matching for surfaces within reach despite systematic visual biases in perceived surface orientation.
Slant perception; proprioception; action measure; perceptual bias; inter-sensory calibration
Wrist distraction is a common treatment maneuver used clinically for the reduction of distal radial fractures and mid-carpal dislocations. Wrist distraction is also required during wrist arthroscopy to access the radiocarpal joint and has been used as a test for scapholunate ligament injury. However, the effect of a distraction load on the normal wrist has not been well studied. The purpose of this study was to measure the 3-D conformational changes of the carpal bones in the normal wrist as a result of a static distractive load.
The dominant wrists of 14 healthy volunteers were scanned using computed tomography at rest and during application of 98N of distraction. Load was applied using finger traps and volunteers were encouraged to relax their forearm muscles and to allow distraction of the wrist. The motions of the bones in the wrist were tracked between the unloaded and loaded trial using markerless bone registration. The average displacement vector of each bone was calculated relative to the radius as well as the interbone distances for 20 bone-bone interactions. Joint separation was estimated at the radiocarpal, midcarpal and carpal-metacarpal joints in the direction of loading using the radius, lunate, capitate and 3rd metacarpal.
With loading, the distance between the radius and 3rd metacarpal increased an average of 3.3±3.1mm in the direction of loading. This separation was primarily located in the axial direction at the radiocarpal (1.0±1.0mm) and midcarpal (2.0±1.7mm) joints. There were minimal changes in the transverse direction within the distal row, although the proximal row narrowed by 0.98±0.7mm. Distraction between the radius and scaphoid (2.5±2.2mm) was 2.4 times greater than between the radius and lunate (1.0±1.0mm).
Carpal distraction has a significant effect on the conformation of the carpus, especially at the radiocarpal and midcarpal joints. In the normal wrist, external traction causes twice as much distraction at the lunocapitate joint than at the radiolunate joint.
Carpal; Kinematics; Distraction; Scaphoid; Lunate
A patient affected by thoracic outlet syndrome, with an
involvement of the left lower primary trunk due to a rudimentary
cervical rib, developed a severe hand dystonia on the same side. The
dystonic posture was characterised by a flexion of the wrist with the
fingers curled into the palm. Polygraphic recordings performed on the left flexor digitorum superficialis (FDS4) and extensor digitorum superficialis (EDC4) muscles, during a repetitive tapping task of the
fourth digit, showed a loss of well formed bursts without a clear
silent period along with long duration bursts of cocontraction in
antagonistic muscles. The study of reciprocal inhibition between forearm flexor and extensor muscles showed a reduced amount of inhibition in both the disynaptic and the later presynaptic phase of
inhibition. The patient underwent an operation with resection of the
cervical rib. Twelve hours after the operation the patient experienced
a significant improvement of the hand dystonia; the distonia had
disappeared completely by two months with a progressive normalisation
of reciprocal inhibition.
This report describes the case management of musculoskeletal disorders for an employee in a college work environment using both chiropractic care and applied ergonomics.
A 54-year-old male office worker presented with decreased motor function in both wrists; intermittent moderate-to-severe headaches; and pain or discomfort in the neck, both shoulders, left hand and wrist, and lumbosacral region resulting from injuries sustained during recreational soccer and from excessive forces and awkward postures when interacting with his home and office computer workstations.
Intervention and Results
Ergonomic training, surveillance, retrofitted equipment with new furniture, and an emphasis on adopting healthy work-style behaviors were applied in combination with regular chiropractic care. Baseline ergonomic job task analysis identified risk factors and delineated appropriate control measures to improve the subject's interface with his office workstation. Serial reevaluations at 3-month, 1-year, and 2-year periods recorded changes to the participant's pain, discomfort, and work-style behaviors. At end of study and relative to baseline, pain scale improved from 4/10 to 2/10; general disability improved from 4 to 0; and hand grip strength (pounds) increased from 20 to 105 (left) and 45 to 100 (right). Healthy work habits and postures adopted in the 3-month to 1-year period regressed to baseline exposures for 3 of 6 risk priorities identified in the ergonomic job task analysis.
The patient responded positively to the intervention of chiropractic care and applied ergonomics.
Human engineering; Chiropractic; Musculoskeletal pain; Posture
The aim of this paper is to investigate mechanical functioning of a single skeletal muscle, active within a group of (previously) synergistic muscles. For this purpose, we assessed wrist angle-active moment characteristics exerted by a group of wrist flexion muscles in the rat for three conditions: (i) after resection of the upper arm skin; (ii) after subsequent distal tenotomy of flexor carpi ulnaris muscle (FCU); and (iii) after subsequent freeing of FCU distal tendon and muscle belly from surrounding tissues (MT dissection). Measurements were performed for a control group and for an experimental group after recovery (5 weeks) from tendon transfer of FCU to extensor carpi radialis (ECR) insertion. To assess if FCU tenotomy and MT dissection affects FCU contributions to wrist moments exclusively or also those of neighboring wrist flexion muscles, these data were compared to wrist angle-moment characteristics of selectively activated FCU. FCU tenotomy and MT dissection decreased wrist moments of the control group at all wrist angles tested, including also angles for which no or minimal wrist moments were measured when activating FCU exclusively. For the tendon transfer group, wrist flexion moment increased after FCU tenotomy, but to a greater extent than can be expected based on wrist extension moments exerted by selectively excited transferred FCU. We conclude that dissection of a single muscle in any surgical treatment does not only affect mechanical characteristics of the target muscle, but also those of other muscles within the same compartment. Our results demonstrate also that even after agonistic-to-antagonistic tendon transfer, mechanical interactions with previously synergistic muscles do remain present.
Carpal bones show hysteresis that is dependent on the direction of wrist motion during a continuous active loading protocol. We describe an accurate methodology for analyzing the hysteresis effect and we apply this model to analyze the effect of sequential ligament sectioning on scapholunate instability.
In 8 fresh cadaver forearms scaphoid, lunate, and third metacarpal motions were recorded while each wrist was moved in continuous cycles of active motion in flexion–extension and radioulnar deviation. Motions were analyzed for the intact state and after sequential sectioning of the scapholunate interosseous, scaphotrapezium, and radioscapho-capitate ligaments. Carpal motion was curve-fitted with respect to the third metacarpal motion using optimization criteria. The area between the 2 curves that represents opposite directions of wrist motion was measured to give the total hysteresis area. Repeated-measures analysis of variance was used to determine significance.
In the flexion–extension trials the scaphoid and lunate total hysteresis area was significantly greater than the intact state only after all 3 ligaments were sectioned. In the radioulnar deviation trials the scaphoid total hysteresis area was significantly greater than the intact after just scapholunate interosseous ligament sectioning; however, the lunate total hysteresis area decreased with additional sequential sectionings in 4 of the 8 specimens as compared with the intact state. These 4 specimens started with a significantly greater intact total hysteresis area than the other 4 specimens.
The computation of the total hysteresis area from the hysteresis effect was found to be a sensitive technique to determine the subtle onset of abnormal carpal motion. By using this technique in a ligament sectioning study significant increases in the total hysteresis area were seen after just scapholunate interosseous ligament sectioning during wrist radioulnar deviation. This subtle change may signify the onset of dynamic scapholunate instability. The total hysteresis area of the lunate in a subset of lax specimens did not increase after ligament sectioning. This divergent behavior may explain why some patients with scapholunate instability do not develop dorsal intercalated segmental instability.
Carpal motion; hysteresis; neutral zone; scapholunate instability
Breast-cancer-related lymphedema affects ∼25% of breast cancer (BC) survivors and may impact use of the upper limb during activity. The purpose of this study is to compare upper extremity (UE) impairment and activity between women with and without lymphedema after BC treatment.
144 women post BC treatment completed demographic, symptom, and Disability of Arm-Shoulder-Hand (DASH) questionnaires. Objective measures included Purdue pegboard, finger-tapper, Semmes-Weinstein monofilaments, vibration perception threshold, strength, range of motion (ROM), and volume.
Women with lymphedema had more lymph nodes removed (p < .001), more UE symptoms (p < .001), higher BMI (p = .041), and higher DASH scores (greater limitation) (p < .001). For all participants there was less strength (elbow flexion, wrist flexion, grip), less shoulder ROM, and decreased sensation at the medial upper arm (p < .05) in the affected UE. These differences were greater in women with lymphedema, particularly in shoulder abduction ROM (p < .05). Women with lymphedema had bilaterally less elbow flexion strength and shoulder ROM (p < .05). Past diagnosis of lymphedema, grip strength, shoulder abduction ROM, and number of comorbidities contributed to the variance in DASH scores (R2 of 0.463, p < .001).
Implications for cancer survivors
UE impairments are found in women following treatment for BC. Women with lymphedema have greater UE impairment and limitation in activities than women without. Many of these impairments are amenable to prevention measures or treatment, so early detection by health care providers is essential.
Lymphedema; Breast cancer; Movement; Impairment; Upper extremity
To test whether the phantom limb awareness could be altered by observing mirror reflection-induced visual feedback (MVF) in unilateral forearm amputees.
Ten unilateral forearm amputees were asked to perform bilateral (intact and phantom) synchronous wrist motions with and without MVF. During wrist motion, electromyographic activities in the extensor digitorum longus (EDL) and flexor carpi radialis muscles (FCR) were recorded with bipolar electrodes. Degree of wrist range of motion (ROM) was also recorded by electrogoniometry attached to the wrist joint of intact side. Subjects were asked to answer the degree of attainment of phantom limb motion using a visual analog scale (VAS: ranging from 0 (hard) to 10 (easy)).
VAS and ROM were significantly increased by utilizing MVF, and the extent of an enhancement of the VAS and wrist ROM was positively correlated (r = 0.72, p<0.05). Although FCR EMG activity also showed significant enhancement by MVF, this was not correlated with the changes of VAS and ROM. Interestingly, while we found negative correlation between EDL EMG activity and wrist ROM, MVF generally affected to be increasing both EDL EMG and ROM.
Although there was larger extent of variability in the effect of MVF on phantom limb awareness, MVF has a potential to enhance phantom limb awareness, in case those who has a difficulty for the phantom limb motion. The present result suggests that the motor command to the missing limb can be re-activated by an appropriate therapeutic strategy such as mirror therapy.
In tennis, injuries to the elbow and wrist occur secondary to the repetitive nature of play and are seen at increasingly young ages. Isokinetic testing can be used to determine muscular strength levels, but dominant/non‐dominant and agonist/antagonist relations are needed for meaningful interpretation of the results.
To determine whether there are laterality differences in wrist extension/flexion (E/F) and forearm supination/pronation (S/P) strength in elite female tennis players.
32 elite female tennis players (age 12 to 16 years) with no history of upper extremity injury underwent bilateral isokinetic testing using a Cybex 6000 dynamometer. Peak torque and single repetition work values for wrist E/F and forearm S/P were measured at speeds of 90°/s and 210°/s, with random determination of the starting extremity. Repeated measures analysis of variance was used to determine differences between extremities for peak torque and single repetition work values.
Significantly greater (p<0.01) dominant arm wrist E/F and forearm pronation strength was measured at both testing speeds. Significantly less (p<0.01) dominant side forearm supination strength was measured at both testing speeds.
Greater dominant arm wrist E/F and forearm pronation strength is common and normal in young elite level female tennis players. These strength relations indicate sport specific muscular adaptations in the dominant tennis playing extremity. The results of this study can guide clinicians who work with young athletes from this population. Restoring greater dominant side wrist and forearm strength is indicated after an injury to the dominant upper extremity in such players.
strength testing; wrist; forearm; tennis
To identify the risk of hand‐wrist disorders related to repetitive movements, use of hand force and wrist position in repetitive monotonous work.
Using questionnaires and physical examinations, the prevalence and incidence of hand‐wrist pain and possible extensor tendonitis (wrist pain and palpation tenderness) were determined in 3123 employees in 19 industrial settings. With the use of questionnaires and video recordings of homogenous work tasks number of wrist movements, hand force requirements and wrist position were analysed as risk factors for hand‐wrist disorders, controlling for potential personal and psychosocial confounders. All participants were re‐examined three times during a follow‐up period of three years.
Force but not repetition and position was related to hand‐wrist pain and possible tendonitis in the baseline analyses showing an exposure‐response pattern. Odds ratios for the risk of hand pain was 1.7 (95% CI 1.3 to 2.2) and for possible tendonitis 1.9 (95% CI 1.1 to 3.3). There was no significant interaction between the ergonomic factors. In the follow‐up analyses force remained a risk factor for hand pain (OR 1.4, 95% CI 1.1 to 1.8) and for possible tendonitis (OR 2.9, 95% CI 1.3 to 6.8). Repetition was also a risk factor for the onset of hand‐wrist pain (OR 1.6, 95% CI 1.2 to 2.3).
Increasing levels of force were associated with prevalent and incident hand‐wrist pain and possible extensor tendonitis. The results for repetition were less consistent. Working with the hand in a non‐neutral position could not be identified as a risk factor.
Loss of elbow flexion due to traumatic palsy of the brachial plexus represents a major functional handicap.
Then, the first goal in the treatment of the flail arm is to restore the elbow flexion by primary direct nerve surgery or secondary reconstructive surgery.
There are various methods to restore elbow flexion which are well documented in the medical literature but the most known and used is Steindler flexorplasty.
This review is intended to detail the author's experience with Steindler flexorplasty to restore elbow flexion in patients with brachial plexus palsy C5-C6-C7 where wrist extensors are paralyzed or weakened.
We conducted a retrospective follow-up study of 12 patients with absent or extremely weak elbow flexion (motor grade 2 or less), wrist/finger extensor and triceps palsy associated; who had undergone surgical reconstruction of the flail upper limb by tendon transfer (Steindler flexorplasty) and wrist arthrodesis to restore elbow flexion. The aetiology of elbow weakness was in all patients brachial plexus palsy (C5-C6-C7 deficit). Data were collected from medical records and from the information obtained during follow-up visits.
Age, sex, preoperative strength (rated on a 0 to 5 scale for the flexors of the elbow, wrist flexors, pronator and triceps), previous surgery, length of follow-up, other associated operative procedures, results and complications were recorded.
The results are the follows: Eleven patients were found to have very good or good function of the transferred muscles. One patient had mild active flexion of the elbow despite the reconstructive procedure.
There were no major intraoperative complications. Two patients experienced transient, intermittent nocturnal ulnar paresthesias postoperatively. In both patients these symptoms subsided without further surgery.
Our study suggests that in patients with C5-C6-C7 palsy where the wrist and finger extensors are paralyzed or weaked, the flexor-pronators muscles of the forearm are strong but the triceps is not available for transfer; Steindler flexorplasty to restore elbow flexion should be complemented with wrist arthrodesis.