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1.  Quadriceps arthrogenic muscle inhibition: the effects of experimental knee joint effusion on motor cortex excitability 
Marked weakness of the quadriceps muscles is typically observed following injury, surgery or pathology affecting the knee joint. This is partly due to ongoing neural inhibition that prevents the central nervous system from fully activating the quadriceps, a process known as arthrogenic muscle inhibition (AMI). This study aimed to further investigate the mechanisms underlying AMI by exploring the effects of experimental knee joint effusion on quadriceps corticomotor and intracortical excitability.
Seventeen healthy volunteers participated in this study. Transcranial magnetic stimulation was used to measure quadriceps motor evoked potential area, short-interval intracortical inhibition, intracortical facilitation and cortical silent period duration before and after experimental knee joint effusion. Joint effusion was induced by the intraarticular infusion of dextrose saline into the knee.
There was a significant increase in quadriceps motor evoked potential area following joint infusion, both at rest (P = 0.01) and during voluntary muscle contraction (P = 0.02). Cortical silent period duration was significantly reduced following joint infusion (P = 0.02). There were no changes in short interval intracortical inhibition or intracortical facilitation over time (all P > 0.05).
The results of this study provide no evidence for a supraspinal contribution to quadriceps AMI. Paradoxically, but consistent with previous observations in patients with chronic knee joint pathology, quadriceps corticomotor excitability increased after experimental knee joint effusion. The increase in quadriceps corticomotor excitability may be at least partly mediated by a decrease in gamma-aminobutyric acid (GABA)-ergic inhibition within the motor cortex.
PMCID: PMC4271337  PMID: 25497133
2.  Diagnostic accuracy of clinical examination features for identifying large rotator cuff tears in primary health care 
Rotator cuff tears are a common and disabling complaint. The early diagnosis of medium and large size rotator cuff tears can enhance the prognosis of the patient. The aim of this study was to identify clinical features with the strongest ability to accurately predict the presence of a medium, large or multitendon (MLM) rotator cuff tear in a primary care cohort.
Participants were consecutively recruited from primary health care practices (n = 203). All participants underwent a standardized history and physical examination, followed by a standardized X-ray series and diagnostic ultrasound scan. Clinical features associated with the presence of a MLM rotator cuff tear were identified (P<0.200), a logistic multiple regression model was derived for identifying a MLM rotator cuff tear and thereafter diagnostic accuracy was calculated.
A MLM rotator cuff tear was identified in 24 participants (11.8%). Constant pain and a painful arc in abduction were the strongest predictors of a MLM tear (adjusted odds ratio 3.04 and 13.97 respectively). Combinations of ten history and physical examination variables demonstrated highest levels of sensitivity when five or fewer were positive [100%, 95% confidence interval (CI): 0.86–1.00; negative likelihood ratio: 0.00, 95% CI: 0.00–0.28], and highest specificity when eight or more were positive (0.91, 95% CI: 0.86–0.95; positive likelihood ratio 4.66, 95% CI: 2.34–8.74).
Combinations of patient history and physical examination findings were able to accurately detect the presence of a MLM rotator cuff tear. These findings may aid the primary care clinician in more efficient and accurate identification of rotator cuff tears that may require further investigation or orthopedic consultation.
PMCID: PMC3744848  PMID: 24421626
Sensitivity; Specificity; Physical examination; Primary health care; Rotator cuff
3.  The effects of commercially available footwear on foot pain and disability in people with gout: a pilot study 
There is limited evidence on non-pharmacological interventions for gout. The aim of the study was to determine whether a footwear intervention can reduce foot pain and musculoskeletal disability in people with gout.
Thirty-six people with gout participated in a prospective intervention study over 8 weeks. Participants selected one of 4 pairs of shoes and thereafter wore the shoes for 8 weeks. The primary outcome was foot pain using a 100 mm visual analogue scale. Secondary outcomes related to function and disability were also analysed.
The Cardio Zip shoe was selected by 58% of participants. Compared with baseline, overall scores for all shoes at 8-weeks demonstrated a decrease in foot pain (p = 0.03), general pain (p = 0.012), Health Assessment Questionnaire (HAQ)-II (p = 0.016) and Leeds Foot Impact Scale (LFIS) impairment subscale (p = 0.03). No significant differences were observed in other patient reported outcomes including patient global assessment, LFIS activity subscale, and Lower Limb Task Questionnaire subscales (all p > 0.10). We observed significant improvements between baseline measurements using the participants’ own shoes and the Cardio Zip for foot pain (p = 0.002), general pain (p = 0.001), HAQ-II (p = 0.002) and LFIS impairment subscale (p = 0.004) after 8 weeks. The other three shoes did not improve pain or disability.
Footwear with good cushioning, and motion control may reduce foot pain and disability in people with gout.
PMCID: PMC3848939  PMID: 24063678
Gout; Pain; Foot; Disability; Joint; Footwear; Comfort
4.  Shoulder pain in primary care: diagnostic accuracy of clinical examination tests for non-traumatic acromioclavicular joint pain 
Despite numerous methodological flaws in previous study designs and the lack of validation in primary care populations, clinical tests for identifying acromioclavicular joint (ACJ) pain are widely utilised without concern for such issues. The aim of this study was to estimate the diagnostic accuracy of traditional ACJ tests and to compare their accuracy with other clinical examination features for identifying a predominant ACJ pain source in a primary care cohort.
Consecutive patients with shoulder pain were recruited prospectively from primary health care clinics. Following a standardised clinical examination and diagnostic injection into the subacromial bursa, all participants received a fluoroscopically guided diagnostic block of 1% lidocaine hydrochloride (XylocaineTM) into the ACJ. Diagnostic accuracy statistics including sensitivity, specificity, predictive values, positive and negative likelihood ratios (LR+ and LR-) were calculated for traditional ACJ tests (Active Compression/O’Brien’s test, cross-body adduction, localised ACJ tenderness and Hawkins-Kennedy test), and for individual and combinations of clinical examination variables that were associated with a positive anaesthetic response (PAR) (P≤0.05) defined as 80% or more reduction in post-injection pain intensity during provocative clinical tests.
Twenty two of 153 participants (14%) reported an 80% PAR. None of the traditional ACJ tests were associated with an 80% PAR (P<0.05) and combinations of traditional tests were not able to discriminate between a PAR and a negative anaesthetic response (AUC 0.507; 95% CI: 0.366, 0.647; P>0.05). Five clinical examination variables (repetitive mechanism of pain onset, no referred pain below the elbow, thickened or swollen ACJ, no symptom provocation during passive glenohumeral abduction and external rotation) were associated with an 80% PAR (P<0.05) and demonstrated an ability to accurately discriminate between an PAR and NAR (AUC 0.791; 95% CI 0.702, 0.880; P<0.001). Less than two positive clinical features resulted in 96% sensitivity (95% CI 0.78, 0.99) and a LR- 0.09 (95% CI 0.02, 0.41) and four positive clinical features resulted in 95% specificity (95% CI 0.90, 0.98) and a LR+ of 4.98 (95% CI 1.69, 13.84).
In this cohort of primary care patients with predominantly subacute or chronic ACJ pain of non-traumatic onset, traditional ACJ tests were of limited diagnostic value. Combinations of other history and physical examination findings were able to more accurately identify injection-confirmed ACJ pain in this cohort.
PMCID: PMC3646690  PMID: 23634871
Sensitivity; Specificity; Shoulder pain; Acromioclavicular joint; Physical examination; Patient history; Local anaesthetic; Primary health care
5.  Influence of stimulation location and posture on the reliability and comfort of the nociceptive flexion reflex 
The lower limb nociceptive flexion reflex (NFR) is commonly used to assess the function of the nociceptive system. Currently, there is a lack of standardized stimulation procedures to determine the NFR threshold, making comparisons of thresholds across studies difficult.
To assess and compare the within- and between-session reliability of NFR threshold when elicited from two common stimulation locations: the medial arch of the foot (while standing) and the sural nerve (while seated).
A staircase procedure was used to determine NFR threshold in 20 healthy participants twice within one session and once more in a separate session approximately four days later. At both sessions, NFR threshold was determined from both medial arch and sural nerve stimulation. Comparisons of NFR threshold, reliability and participant discomfort ratings were made between the two stimulation locations.
NFR thresholds were statistically equivalent at the two stimulation locations, but there were more nonresponders and ratings of participant discomfort were significantly higher during stimulation over the sural nerve. Within-session reliability measures were superior for stimulation over the sural nerve; however, between-session measures were more reliable using stimulation over the medial arch of the foot.
The authors recommend stimulation over the medial arch of the foot while standing as the preferred location for eliciting the lower limb NFR, particularly if measurements are to be compared across multiple sessions.
PMCID: PMC3393053  PMID: 22518374
Flexion reflex; Lower limb; Reliability
6.  Reliability of the conditioned pain modulation paradigm to assess endogenous inhibitory pain pathways 
Conditioned pain modulation paradigms are often used to assess the diffuse noxious inhibitory control (DNIC) system. DNICs provide one of the main supraspinal pain inhibitory pathways and are impaired in several chronic pain populations. Only one previous study has examined the psychometric properties of the conditioned pain modulation technique and this study did not evaluate intersession reliability.
To evaluate and compare the intra- and intersession reliability of two conditioned pain modulation paradigms using different conditioning stimuli, and to determine the time course of conditioned pain inhibition following stimulus removal.
An electronic pressure transducer was used to determine the pressure-pain threshold at the knee during painful conditioning of the opposite hand using the ischemic arm test and the cold pressor test. Assessments were completed twice on one day and repeated once approximately three days later.
The two conditioning stimuli resulted in a similar increase in the pressure-pain threshold at the knee, reflecting presumed activation of the DNIC system. Intrasession intraclass correlation coefficients for the cold pressor (0.85) and ischemic arm tests (0.75) were excellent. The intersession intraclass correlation coefficient for the cold pressor test was good (0.66) but was poor for the ischemic arm test (−0.4). Inhibition of the pressure-pain threshold remained significant at 10 min following conditioning, but returned to baseline by 15 min.
Within-session reliability of DNIC assessment using conditioned pain modulation paradigms was excellent, but the applicability of assessing pain modulation over multiple sessions was influenced by the conditioning stimulus. The cold pressor test was the superior technique.
PMCID: PMC3393056  PMID: 22518372
Diffuse noxious inhibitory control; Pain; Reliability
7.  Active Stiffness and Strength in People With Unilateral Anterior Shoulder Instability: A Bilateral Comparison 
Journal of Athletic Training  2011;46(6):642-647.
Active muscle stiffness might protect the unstable shoulder from recurrent dislocation.
To compare strength and active stiffness in participants with unilateral anterior shoulder instability and to examine the relationship between active stiffness and functional ability.
Cross-sectional study.
University research laboratory.
Patients or Other Participants:
Participants included 16 males (age range, 16–40 years; height = 179.4 ± 6.1 cm; mass = 79.1 ± 6.8 kg) with 2 or more episodes of unilateral traumatic anterior shoulder instability.
Main Outcome Measure(s):
Active stiffness and maximal voluntary strength were measured bilaterally in participants. In addition, quality of life, function, and perceived instability were measured using the Western Ontario Stability Index, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, and Single Alpha Numeric Evaluation, respectively.
We found less horizontal adduction strength (t15 = −4.092, P = .001) and less stiffness at 30% (t14 = −3.796, P = .002) and 50% (t12 = −2.341, P = .04) maximal voluntary strength in the unstable than stable shoulder. Active stiffness was not correlated with quality of life, function, or perceived instability (r range, 0.0–0.25; P > .05).
The observed reduction in stiffness in the unstable shoulder warrants inclusion of exercises in the rehabilitation program to protect the joint from perturbations that might lead to dislocation. The lack of association between active stiffness and quality of life, function, or perceived instability might indicate that stiffness plays a less direct role in shoulder stability.
PMCID: PMC3418942  PMID: 22488190
recurrent instability; recurrent dislocations; glenohumeral instability; recurrent glenohumeral dislocations
Levels of evidence allow clinicians to appreciate the quality of a particular research paper quickly. The levels are generally set out in a hierarchical order, which is based largely upon the experimental design. While there are ideal designs for studies examining the effects of interventions, risk factors for a clinical condition or diagnostic testing, in most instances researchers have had to make compromises and these subsequently decrease the quality of their work. This paper provides information concerning how those compromises relate to subsequent levels that are given to a piece of research. It also provides an understanding of issues related to evaluating papers, and suggest ways in which the reader might discern how relevant a paper might be to one's clinical practice.
PMCID: PMC3474306  PMID: 23091779
levels of evidence; research design; study quality
9.  Optimizing muscle power after stroke: a cross-sectional study 
Stroke remains a leading cause of disability worldwide and results in muscle performance deficits and limitations in activity performance. Rehabilitation aims to address muscle dysfunction in an effort to improve activity and participation. While muscle strength has an impact on activity performance, muscle power has recently been acknowledged as contributing significantly to activity performance in this population. Therefore, rehabilitation efforts should include training of muscle power. However, little is known about what training parameters, or load, optimize muscle power performance in people with stroke. The purpose of this study was to investigate lower limb muscle power performance at differing loads in people with and without stroke.
A cross-sectional study design investigated muscle power performance in 58 hemiplegic and age matched control participants. Lower limb muscle power was measured using a modified leg press machine at 30, 50 and 70% of one repetition maximum (1-RM) strength.
There were significant differences in peak power between involved and uninvolved limbs of stroke participants and between uninvolved and control limbs. Peak power was greatest when pushing against a load of 30% of 1RM for involved, uninvolved and control limbs. Involved limb peak power irrespective of load (Mean:220 ± SD:134 W) was significantly lower (p < 0.05) than the uninvolved limb (Mean:466 ± SD:220 W). Both the involved and uninvolved limbs generated significantly lower peak power (p < 0.05) than the control limb (Mean:708 ± SD:289 W).
Significant power deficits were seen in both the involved and uninvolved limbs after stroke. Maximal muscle power was produced when pushing against lighter loads. Further intervention studies are needed to determine whether training of both limbs at lighter loads (and higher velocities) are preferable to improve both power and activity performance after stroke.
PMCID: PMC3481454  PMID: 23013672
Hemiplegia; Hemi paresis; Cerebrovascular accident; Stroke; Leg extensor; Power; Strength; Power; Rehabilitation
10.  Enhancing Medicare's Hospital-Acquired Conditions Policy to Encompass Readmissions 
Medicare & Medicaid Research Review  2012;2(2):mmrr.002.02.a03.
The current Medicare policy of non-payment to hospitals for Hospital-Acquired Conditions (HAC) seeks to avoid payment for preventable complications identified within a single admission. The financial impact ($1 million–$50 million/yr) underestimates the true financial impact of HACs when readmissions are taken into account.
Define and quantify acute inpatient readmissions arising directly from, or completing the definition of, the current HACs.
Research Design
Observational study
All non-federal inpatient admissions to California hospitals, July 2006 to June 2007 with a recorded Social Security number.
Readmission to acute care within 1 day for acute complications of poor glycemic control; 7 days for iatrogenic air emboli, incompatible blood transfusions, catheter-associated urinary tract infections and vascular catheter-associated infections; 30 days for deep vein thromboses or pulmonary emboli following hip or knee replacement surgery; and 183 days for foreign objects retained after surgery, mediastinitis following coronary artery bypass grafts, injuries sustained during inpatient care, infections following specific joint or bariatric surgery procedures, and pressure ulcers stages III & IV.
An additional estimated $103 million in payments would be withheld if Medicare expands the policy to include non-payment for HAC related readmissions. The majority (90%) of this impact involves mediastinitis, post-orthopedic surgery infection, or fall related injury.
Limiting the current HAC policy focus to complications identified during the index admission omits consideration of many complications only identified in a subsequent admission. Non-payment for HAC-related readmissions would enhance incentives for prevention by increasing the frequency with which hospitals are held accountable for HACs.
PMCID: PMC4006390  PMID: 24800141
Funding; Inpatient; Hospital-Acquired Conditions; Readmissions
11.  Mechanisms of quadriceps muscle weakness in knee joint osteoarthritis: the effects of prolonged vibration on torque and muscle activation in osteoarthritic and healthy control subjects 
Arthritis Research & Therapy  2011;13(5):R151.
A consequence of knee joint osteoarthritis (OA) is an inability to fully activate the quadriceps muscles, a problem termed arthrogenic muscle inhibition (AMI). AMI leads to marked quadriceps weakness that impairs physical function and may hasten disease progression. The purpose of the present study was to determine whether γ-loop dysfunction contributes to AMI in people with knee joint OA.
Fifteen subjects with knee joint OA and 15 controls with no history of knee joint pathology participated in this study. Quadriceps and hamstrings peak isometric torque (Nm) and electromyography (EMG) amplitude were collected before and after 20 minutes of 50 Hz vibration applied to the infrapatellar tendon. Between-group differences in pre-vibration torque were analysed using a one-way analysis of covariance, with age, gender and body mass (kg) as the covariates. If the γ-loop is intact, vibration should decrease torque and EMG levels in the target muscle; if dysfunctional, then torque and EMG levels should not change following vibration. One-sample t tests were thus undertaken to analyse whether percentage changes in torque and EMG differed from zero after vibration in each group. In addition, analyses of covariance were utilised to analyse between-group differences in the percentage changes in torque and EMG following vibration.
Pre-vibration quadriceps torque was significantly lower in the OA group compared with the control group (P = 0.005). Following tendon vibration, quadriceps torque (P < 0.001) and EMG amplitude (P ≤0.001) decreased significantly in the control group but did not change in the OA group (all P > 0.299). Hamstrings torque and EMG amplitude were unchanged in both groups (all P > 0.204). The vibration-induced changes in quadriceps torque and EMG were significantly different between the OA and control groups (all P < 0.011). No between-group differences were observed for the change in hamstrings torque or EMG (all P > 0.554).
γ-loop dysfunction may contribute to AMI in individuals with knee joint OA, partially explaining the marked quadriceps weakness and atrophy that is often observed in this population.
PMCID: PMC3308081  PMID: 21933392
12.  A prospective study of shoulder pain in primary care: Prevalence of imaged pathology and response to guided diagnostic blocks 
The prevalence of imaged pathology in primary care has received little attention and the relevance of identified pathology to symptoms remains unclear. This paper reports the prevalence of imaged pathology and the association between pathology and response to diagnostic blocks into the subacromial bursa (SAB), acromioclavicular joint (ACJ) and glenohumeral joint (GHJ).
Consecutive patients with shoulder pain recruited from primary care underwent standardised x-ray, diagnostic ultrasound scan and diagnostic injections of local anaesthetic into the SAB and ACJ. Subjects who reported less than 80% reduction in pain following either of these injections were referred for a magnetic resonance arthrogram (MRA) and GHJ diagnostic block. Differences in proportions of positive and negative imaging findings in the anaesthetic response groups were assessed using Fishers test and odds ratios were calculated a for positive anaesthetic response (PAR) to diagnostic blocks.
In the 208 subjects recruited, the rotator cuff and SAB displayed the highest prevalence of pathology on both ultrasound (50% and 31% respectively) and MRA (65% and 76% respectively). The prevalence of PAR following SAB injection was 34% and ACJ injection 14%. Of the 59% reporting a negative anaesthetic response (NAR) for both of these injections, 16% demonstrated a PAR to GHJ injection. A full thickness tear of supraspinatus on ultrasound was associated with PAR to SAB injection (OR 5.02; p < 0.05). Ultrasound evidence of a biceps tendon sheath effusion (OR 8.0; p < 0.01) and an intact rotator cuff (OR 1.3; p < 0.05) were associated with PAR to GHJ injection. No imaging findings were strongly associated with PAR to ACJ injection (p ≤ 0.05).
Rotator cuff and SAB pathology were the most common findings on ultrasound and MRA. Evidence of a full thickness supraspinatus tear was associated with symptoms arising from the subacromial region, and a biceps tendon sheath effusion and an intact rotator cuff were associated with an intra-articular GHJ pain source. When combined with clinical information, these results may help guide diagnostic decision making in primary care.
PMCID: PMC3127806  PMID: 21619663
14.  CMS Changes in Reimbursement for HAIs 
Medical care  2010;48(5):433-439.
The Centers for Medicare and Medicaid Services (CMS) promulgated regulations commencing October 1, 2008, which deny payment for selected conditions occurring during the hospital stay and are not present on admission. Three of the 10 hospital-acquired conditions covered by the new CMS policy involve healthcare-associated infections, which are a common, expensive, and often preventable cause of inpatient morbidity and mortality.
To outline a research agenda on the impact of CMS’s payment policy on the healthcare system and the prevention of healthcare-associated infections.
An invitational daylong conference was convened in April 2009. Including the planning committee and speakers there were 41 conference participants who were national experts and senior researchers.
Building upon a behavioral model and organizational theory and management research a conceptual framework was applied to organize the wide range of issues that arose. A broad array of research topics was identified. Thirty-two research agenda items were organized in the areas of incentives, environmental factors, organizational factors, clinical outcomes, staff outcomes, and financial outcomes. Methodological challenges are also discussed.
This policy is a first significant step to move output-based inpatient funding to outcome-based funding, and this agenda is applicable to all hospital-acquired conditions. Studies beginning soon will have the best hope of capturing data for the years preceding the policy change, a key element in nonexperimental research. The CMS payment policy offers an excellent opportunity to understand and influence the use of financial incentives for improving patient safety.
PMCID: PMC2881841  PMID: 20351584
pay-for-performance; healthcare-associated infections; quality; health policy
15.  Constructing Clinical Decision Support Systems for Adverse Drug Event Prevention: A Knowledge-based Approach 
A knowledge-based approach is proposed that is employed for the construction of a framework suitable for the management and effective use of knowledge on Adverse Drug Event (ADE) prevention. The framework has as its core part a Knowledge Base (KB) comprised of rule-based knowledge sources, that is accompanied by the necessary inference and query mechanisms to provide healthcare professionals and patients with decision support services in clinical practice, in terms of alerts and recommendations on preventable ADEs. The relevant Knowledge Based System (KBS) is developed in the context of the EU-funded research project PSIP (Patient Safety through Intelligent Procedures in Medication). In the current paper, we present the foundations of the framework, its knowledge model and KB structure, as well as recent progress as regards the population of the KB, the implementation of the KBS, and results on the KBS verification in decision support operation.
PMCID: PMC3041377  PMID: 21347009
16.  Exercise therapy for the management of osteoarthritis of the hip joint: a systematic review 
Recent guidelines pertaining to exercise for individuals with osteoarthritis have been released. These guidelines have been based primarily on studies of knee-joint osteoarthritis. The current study was focused on the hip joint, which has different biomechanical features and risk factors for osteoarthritis and has received much less attention in the literature. The purpose was to conduct a systematic review of the literature to evaluate the exercise programs used in intervention studies focused solely on hip-joint osteoarthritis, to decide whether their exercise regimens met the new guidelines, and to determine the level of support for exercise-therapy interventions in the management of hip-joint osteoarthritis.
A systematic literature search of 14 electronic databases was undertaken to identify interventions that used exercise therapy as a treatment modality for hip osteoarthritis. The quality of each article was critically appraised and graded according to standardized methodologic approaches. A 'pattern-of-evidence' approach was used to determine the overall level of evidence in support of exercise-therapy interventions for treating hip osteoarthritis.
More than 4,000 articles were identified, of which 338 were considered suitable for abstract review. Of these, only 6 intervention studies met the inclusion criteria. Few well-designed studies specifically investigated the use of exercise-therapy management on hip-joint osteoarthritis. Insufficient evidence was found to suggest that exercise therapy can be an effective short-term management approach for reducing pain levels, improving joint function and the quality of life.
Limited information was available on which conclusions regarding the efficacy of exercise could be clearly based. No studies met the level of exercise recommended for individuals with osteoarthritis. High-quality trials are needed, and further consideration should be given to establishing the optimal exercises and exposure levels necessary for achieving long-term gains in the management of osteoarthritis of the hip.
PMCID: PMC2714154  PMID: 19555502
17.  Reliability and Measurement Error of Active Knee Extension Range of Motion in a Modified Slump Test Position: A Pilot Study 
The slump test is a tool to assess the mechanosensitivity of the neuromeningeal structures within the vertebral canal. While some studies have investigated the reliability of aspects of this test within the same day, few have assessed the reliability across days. Therefore, the purpose of this pilot study was to investigate reliability when measuring active knee extension range of motion (AROM) in a modified slump test position within trials on a single day and across days. Ten male and ten female asymptomatic subjects, ages 20–49 (mean age 30.1, SD 6.4) participated in the study. Knee extension AROM in a modified slump position with the cervical spine in a flexed position and then in an extended position was measured via three trials on two separate days. Across three trials, knee extension AROM increased significantly with a mean magnitude of 2° within days for both cervical spine positions (P>0.05). The findings showed that there was no statistically significant difference in knee extension AROM measurements across days (P>0.05). The intraclass correlation coefficients for the mean of the three trials across days were 0.96 (lower limit 95% CI: 0.90) with the cervical spine flexed and 0.93 (lower limit 95% CI: 0.83) with cervical extension. Measurement error was calculated by way of the typical error and 95% limits of agreement, and visually represented in Bland and Altman plots. The typical error for the cervical flexed and extended positions averaged across trials was 2.6° and 3.3°, respectively. The limits of agreement were narrow, and the Bland and Altman plots also showed minimal bias in the joint angles across days with a random distribution of errors across the range of measured angles. This study demonstrated that knee extension AROM could be reliably measured across days in subjects without pathology and that the measurement error was acceptable. Implications of variability over multiple trials are discussed. The modified set-up for the test using the Kincom dynamometer and elevated thigh position may be useful to clinical researchers in determining the mechanosensitivity of the nervous system.
PMCID: PMC2565640  PMID: 19066666
Modified Slump Test; Knee Extension; Within-Trial Reliability; Reliability across Days; Measurement Error
18.  Effect of passive stretching and jogging on the series elastic muscle stiffness and range of motion of the ankle joint 
To determine the effect of stretching and jogging on the series elastic muscle stiffness of the plantar flexors and on the range of dorsiflexion at the ankle joint.
24 healthy subjects participated in this study. Each subject undertook all of the following protocols, in random order: (1) stretching protocol: five 30 s static stretches with 30 s rest between stretches; (2) aerobic jogging protocol: subjects ran on a treadmill for 10 min at 60% of their maximum age predicted heart rate; (3) combined protocol: subjects ran first and then stretched. A damped oscillation technique was used to measure the series elastic stiffness of the plantar flexors. Dorsiflexion of the ankle was assessed with a weights and pulley system that moved the ankle joint from a neutral position into dorsiflexion passively. Electromyography was used to monitor the activity of the plantar and dorsiflexors during these procedures. The statistical analysis of these data involved an analysis of covariance
For decreasing series elastic muscle stiffness running was more effective than stretching (P<0.05). In contrast, the results for range of motion showed that the combination protocol and the stretching only protocol were more effective than the running only protocol (P < 0.05) for increasing dorsiflexion range of motion at the ankle.
Both jogging and static stretching exercises appear to be beneficial to individuals participating in sporting activities.
PMCID: PMC1332414  PMID: 9015593
warm up; stretching; muscle stiffness; joint range of motion
19.  Verbal encouragement: effects on maximum effort voluntary muscle: action 
To examine the effects of verbal encouragement on the peak force of the elbow flexors during an isometric muscle action.
A crossover design whereby 20 subjects were divided into 10 2×2 Latin squares was undertaken. Peak forces were measured on a Kin-Com dynamometer, and electromyographic (EMG) activity was also recorded from the biceps brachii. All subjects completed trials with and without verbal encouragement.
Mean peak force increased (P<0.05) from 296 to 311 N (5%) when verbal encouragement was presented. A spectral analysis of the EMG activity showed no changes (P>0.05) to the median frequency in the condition where verbal encouragement was present.
These findings have ramifications for training and exercise therapy. An awareness of the effects of verbal encouragement is important when motivating athletes and patients to attain maximum performance during exercise.
PMCID: PMC1332340  PMID: 8889120
strength; verbal; performance; psychological influences

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