Muscle stiffness indicating mission crew health in space.

Muscle function is compromised by gravitational unloading in space affecting overall musculoskeletal health. Astronauts perform daily exercise programmes to mitigate these effects but knowing which muscles to target would optimise effectiveness. Accurate inflight assessment to inform exercise programmes is critical due to lack of technologies suitable for spaceflight. Changes in mechanical properties indicate muscle health status and can be measured rapidly and non-invasively using novel technology. A hand-held MyotonPRO device enabled monitoring of muscle health for the first time in spaceflight (> 180 days). Greater/maintained stiffness indicated countermeasures were effective. Tissue stiffness was preserved in the majority of muscles (neck, shoulder, back, thigh) but Tibialis Anterior (foot lever muscle) stiffness decreased inflight vs. preflight (p < 0.0001; mean difference 149 N/m) in all 12 crewmembers. The calf muscles showed opposing effects, Gastrocnemius increasing in stiffness Soleus decreasing. Selective stiffness decrements indicate lack of preservation despite daily inflight countermeasures. This calls for more targeted exercises for lower leg muscles with vital roles as ankle joint stabilizers and in gait. Muscle stiffness is a digital biomarker for risk monitoring during future planetary explorations (Moon, Mars), for healthcare management in challenging environments or clinical disorders in people on Earth, to enable effective tailored exercise programmes.

Effects of slouched sitting posture on clavicular and scapular orientations and movements in individuals with neck pain with scapular dysfunction.

BACKGROUND: It has been suggested that sitting posture affects clavicular, scapular and spinal kinematics, however its effects in people with neck pain and scapular dysfunction remain unknown. The study aimed to determine the clavicular and scapular kinematics in different sitting postures in patients with neck pain and scapular dysfunction. METHODS: Thirty-four participants with neck pain and scapular dysfunction were recruited into the study. Kinematics of the clavicle and scapula were recorded using motion analysis at rest and during arm elevation (at 30, 60, 90, and 120 degrees) in a slouched and upright sitting posture. RESULTS: Compared to the upright sitting posture, the slouched sitting posture had increased clavicular protraction and elevation as well as scapular internal rotation and anterior tilt at rest and during the arm raising and lowering phases (at 30, 60, 90, and 120 degrees) (p < 0.05). The slouched sitting also had increased scapular upward rotation in the lowering phase at all angles (p < 0.05). SIGNIFICANCE: The slouched sitting posture has a significant influence on clavicular and scapular kinematics. Awareness of good sitting posture should be encouraged in patients with neck pain and scapular dysfunction.

Axioscapular and neck extensor muscle behavior during isometric shoulder exertions in patients with nonspecific neck pain with and without a scapular downward rotation posture.

BACKGROUND: A common observation in persons with neck pain is scapular downward rotation (SDR) with altered muscle behavior. Evidence of changes in axioscapular muscles in neck pain patients remains inconclusive, which may reflect population heterogeneity in previous studies. RESEARCH QUESTION: Are there differences in behavior of the axioscapular (upper trapezius: UT, lower trapezius: LT and serratus anterior: SA) and neck extensor (NE) muscles during isometric shoulder tasks in patients with neck pain with SDR, patients with no scapular dysfunction and healthy controls? METHODS: Sixty participants with nonspecific neck pain (30 with SDR and 30 without scapular dysfunction) and 30 controls were recruited. Electromyographic signals were recorded unilaterally from the UT, LT, SA and NE during different isometric shoulder tasks (30° flexion, 30°abduction and 30°external rotation) at 20%, 50% and 100% maximal voluntary contraction (MVC). Activity of UT, LT, SA and NE was normalized with respect to reference contractions. The UT/LT, UT/SA and LT/SA ratios were calculated for each task. RESULTS: The neck pain group with SDR had increased UT activity in 30°flexion (20%MVC) and 30°abduction (20% and 50%MVC) compared to the neck pain and control groups without scapular dysfunction (p < 0.05). There were no between group differences in LT and SA activity (p > 0.05). The neck pain groups had greater NE activity in all tasks (p < 0.001). Finally, the neck pain group with SDR had higher UT/LT and UT/SA ratios in a few tasks at low force levels (p ≤ 0.01). SIGNIFICANCE: Greater UT activity and UT/LT and UT/SA ratios during particularly low force isometric shoulder tasks suggest that SDR is associated with altered axioscapular motor control. Greater NE activity in both neck pain groups suggests altered motor control related to neck pain. Changes in the NE and UT behavior should be considered in management of patients with neck pain with observable SDR.

Strength and Balance in Recreational Golfers and Non-Golfers Aged 65-79 Years in Community Settings.

Inactive older adults tend to have decreased strength and balance compared with their more active peers. Playing golf has the potential to improve strength and balance in older adults. The aim of the study was to compare the strength and balance of recreational golfers with non-golfers, aged 65-79 years. Grip strength, single leg balance, and Y Balance Test (YBT) were assessed. Golfers (n = 57) had significantly (right, p = .042; left, p = .047) higher maximal grip strength, than non-golfers (n = 17). Single leg stance times were significantly longer in golfers (right, p = .021; left, p = .001). Normalized YBT reach distances were significantly greater for golfers than non-golfers for composite, posteromedial, and posterolateral directions on both right and left legs. Playing golf appears to be associated with better grip and both static and dynamic balance in 65-79 year olds, indicating that a study of the effects of playing golf is warranted through a larger, fully powered, longitudinal study.

Validity and reliability of sensor system to measure trunk range of motion during Streamlined Wolf Motor Function Test in chronic stroke and aged-matched healthy participants.

OBJECTIVE: To investigate the validity and reliability of using the Valedo® system to measure trunk Range of Motion (ROM) during performance of the streamlined Wolf Motor Function Test (SWMFT). METHODS: Twenty chronic strokes and 20 age-matched healthy participants performed SWMFT while wearing Valedo® sensors on their trunks to capture trunk movements. A paired sample T-test was used to examine the validity of the system in distinguishing between the healthy and stroke group, and between the affected and unaffected sides in the stroke group. Interclass correlation coefficients were used to assess the inter-rater and intra-rater reliability (between-days) with 95% CI. RESULTS: The Valedo® system was able to distinguish between stroke and healthy participants; stroke participants employed greater trunk range of movements than the healthy controls in all tasks (p < .01). Furthermore, the Valedo® system enabled differentiation between affected and unaffected hands of people within the stroke group. The reliability for the stroke group was good to excellent with intrarater reliability (ICC = 0.71-0.92) and interrater reliability (ICC = 0.63-0.95). CONCLUSIONS: The Valedo system demonstrates an acceptable level of validity and reliability for measuring trunk ROM during the Streamlined Wolf Motor Function Test (SWMFT). Future studies with a larger sample size, different levels of upper limb impairment are warranted.

Protocol and reference values for minimal detectable change of MyotonPRO and ultrasound imaging measurements of muscle and subcutaneous tissue.

The assessment of muscle health is of paramount importance, as the loss of muscle mass and strength can affect performance. Two non-invasive tools that have been found to be useful in this are the MyotonPRO and rehabilitative ultrasound imaging, both have shown to be reliable in previous studies many of which conducted by the research team. This study aims to determine the reliability of previously unassessed local body structures and to determine their minimal detectable changes (MDC) to support both researchers and clinicians. Twenty healthy participants were recruited to determine the reliability of seven skin positions out of a previously established protocol. Reliability was determined between three independent raters, and day to day reliability was assessed with one rater a week apart. Intraclass Correlation Coefficients (ICC) between raters and between days for tissue stiffness, tone and elasticity range from moderate to excellent (ICC 0.52-0.97), with most good or excellent. ICCs for subcutaneous thickness between days was good or excellent (ICC 0.86-0.91) and moderate to excellent between raters (ICC 0.72-0.96), in muscles it was moderate to excellent between raters and days (ICC 0.71-0.95). The protocol in this study is repeatable with overall good reliability, it also provides established MDC values for several measurement points.

3D measurement of clavicular and scapular orientations: The association with clinical characteristics and responsiveness to scapular repositioning in patients with neck pain.

BACKGROUND: Clavicular and scapular orientations vary between neck pain patients as do clinical features and responses (changes in pain and rotation range) to scapular repositioning. Associations between these factors are unknown. OBJECTIVES: To identify subgroups of neck pain patients based on three-dimensional (3D) measures of clavicular and scapular orientations and differences between subgroups in clinical characteristics and responses to scapular repositioning. DESIGN: Cross-sectional study. METHODS: Eligible participants were recruited as part of a larger study. The 3D clavicular and scapular orientations were analyzed on the more painful side of the neck using a hierarchical cluster analysis. Clinical characteristics were neck pain location, intensity, duration, disability and presence of headache. Responses to scapular repositioning were classified as "yes and no". RESULTS: Fifty-eight participants (29 responsive; 29 non-responsive to scapular repositioning) participated in the study. Analysis identified two distinct subgroups: subgroup1 had greater clavicular retraction and scapular downward rotation (n = 26) and subgroup2 had greater clavicular elevation and scapular internal rotation and anterior tilt (n = 32). Headache and dominant pain in the upper neck were more frequent in subgroup 1 while dominant pain in the lower neck was frequent in subgroup 2 (p < 0.01). Most participants who responded positively to scapular repositioning (88.5%) were in subgroup1 and most non-responsive participants (81.2%) in subgroup2. CONCLUSIONS: The 3D clavicular and scapular orientations identified two subgroups of neck pain patients. Participants with predominantly downward scapular rotation were distinguished by pain in the upper neck, presence of headache and a positive response to scapular repositioning.

Clavicular and scapular, but not spinal kinematics vary with scapular dyskinesis type during arm elevation and lowering in persons with neck pain.

BACKGROUND: Scapular dyskinesis is often observed in patients with neck pain. However, it is unknown whether clavicular, scapular and spinal kinematics vary with different types of scapular dyskinesis during arm movement. RESEARCH QUESTION: Are there differences in clavicular, scapular and spinal kinematics during unilateral arm elevation and lowering among neck pain patients presenting with (i) scapular winging, (ii) with dysrhythmia, (iii) with no scapular abnormality and (iv) healthy controls? METHODS: Sixty participants with neck pain (20 in each group) and 20 asymptomatic controls were recruited. The 3D kinematic data were measured during unilateral arm elevation and lowering at 30°, 60°, 90°, and 120° in the scapular plane. A three-way mixed-effects ANOVA was used to determine the main effects (group, phase and angle) and the interactions between three independent variables on the kinematic data. RESULTS: The neck pain group with scapular winging had decreased clavicular retraction and increased scapular internal rotation and anterior tilt compared to the other neck pain and control groups at all angles during both phases of arm movement (p < 0.01). The neck pain group with scapular dysrhythmia had decreased scapular upward rotation compared to all other groups (p < 0.01). Some alterations in the kinematics existed during the lowering phase compared to the raising phase for all groups (p < 0.05). Spinal kinematics were similar across all groups (p > 0.05). SIGNIFICANCE: Specific patterns of clavicular and scapular kinematics were identified during arm movement relevant to the type of observed scapular dyskinesis in patients with neck pain. Such findings stand to inform more precise and relevant motor training in rehabilitation and improve understanding of the association between altered scapular kinematics and neck pain.

Physical activity levels and shoulder pain in wheelchair users during COVID-19 restrictions.

BACKGROUND: Manual wheelchair users are at high risk of developing shoulder pain. However, it is not known if restrictions to limit the spread of the COVID-19 virus affected physical activity, wheelchair use and shoulder pain. OBJECTIVE: The aim of the study is to determine whether COVID-19 related restrictions caused changes in physical activity levels and the presence of shoulder pain in persons who use a wheelchair. METHODS: Manual wheelchair users completed a survey about the presence and severity of shoulder pain in a cross-sectional study design. Participants completed the Leisure Time Physical Activity Questionnaire and were asked about daily wheelchair activity before and during lockdown. A logistic regression examined the relationship between increase in shoulder pain severity and change in activity levels. RESULTS: Sixty respondents were included for analysis. There was no significant change in physical activity during lockdown. There was a significant reduction in number of hours of daily wheelchair use and number of chair transfers during lockdown. Of the respondents, 67% reported having shoulder pain and 22% reported their shoulder pain becoming more severe during lockdown. No significant relationship was observed between the change in activity levels and increasing severity of shoulder pain. CONCLUSION: Restrictions to reduce the spread of the COVID-19 virus resulted in no changes in physical activity levels in a sample of adult manual wheelchair users; however, there was a reduced time using a wheelchair each day and fewer chair transfers. The changes in wheelchair activities were not related to the worsening of shoulder pain.

Longitudinal analysis of the recovery of trunk control and upper extremity following stroke: An individual growth curve approach.

BACKGROUND AND PURPOSE: Trunk control is thought to contribute to upper extremity function. It is unclear whether recovery of trunk control has an impact on the recovery of the upper extremity in people with stroke. This longitudinal study monitored the recovery of trunk control and upper extremity in the first 6 months following stroke. METHODS: Forty-five participants with stroke were assessed monthly for 6 months following stroke. Trunk control was assessed using the Trunk Impairment Scale (TIS); upper extremity impairment and function were assessed with the Fugl-Meyer (FMA) and Streamlined Wolf Motor Function Test (SWMFT) respectively. The SWMFT included the performance time (SWMFT-Time) and functional ability scale (SWMFT-FAS). The individual growth curve modeling was used to analyze the longitudinal data. RESULTS: The recovery curve of TIS, FMA, SWMFT-Time and SWMFT-FAS followed a quadratic trend, with the rate of recovery decreasing from the first to sixth month. As TIS score improved over time, FMA, SWMFT-Time and SWMFT-FAS improved in parallel with the TIS score. TIS at each time point was found to be a significant predictor of FMA, SWMFT-Time and SWMFT-FAS at 6 months post stroke. CONCLUSION: Our work has provided, for the first time, substantial evidence that the pattern of recovery of trunk control is similar to that of the recovery of upper extremity following stroke. In addition, this study provides evidence on which to design a prospective study to evaluate whether improvement in trunk control early post-stroke results in better long-term upper extremity function.

Non-Invasive Biomarkers of Musculoskeletal Health with High Discriminant Ability for Age and Gender.

A novel approach to ageing studies assessed the discriminatory ability of a combination of routine physical function tests and novel measures, notably muscle mechanical properties and thigh composition (ultrasound imaging) to classify healthy individuals according to age and gender. The cross-sectional study included 138 community-dwelling, self-reported healthy males and females (65 young, mean age ± SD = 25.7 ± 4.8 years; 73 older, 74.9 ± 5.9 years). Handgrip strength; quadriceps strength; respiratory peak flow; timed up and go; stair climbing time; anterior thigh tissue thickness; muscle stiffness, tone, elasticity (Myoton technology), and self-reported health related quality of life (SF36) were assessed. Stepwise feature selection using cross-validation with linear discriminant analysis was used to classify cases based on criterion variable derived from known effects of age on physical function. A model was trained and features selected using 126 cases with 0.92 accuracy (95% CI = 0.86-0.96; Kappa = 0.89). The final model included five features (peak flow, timed up and go, biceps brachii elasticity, anterior thigh muscle thickness, and percentage thigh muscle) with high sensitivity (0.82-0.96) and specificity (0.94-0.99). The most sensitive novel biomarkers require no volition, highlighting potentially useful tests for screening and monitoring effects of interventions on musculoskeletal health for vulnerable older people with pain or cognitive impairment.

Crank length alters kinematics and kinetics, yet not the economy of recumbent handcyclists at constant handgrip speeds.

Handcycling performance is dependent on the physiological economy of the athlete; however, handbike configuration and the biomechanical interaction between the two are also vital. The purpose of this study was to examine the effect of crank length manipulations on physiological and biomechanical aspects of recumbent handcycling performance in highly trained recumbent handcyclists at a constant linear handgrip speed and sport-specific intensity. Nine competitive handcyclists completed a 3-minute trial in an adjustable recumbent handbike in four crank length settings (150, 160, 170 & 180 mm) at 70% peak power output. Handgrip speed was controlled (1.6 m·s-1 ) across trials with cadences ranging from 102 to 85 rpm. Physiological economy, heart rate, and ratings of perceived exertion were monitored in all trials. Handcycling kinetics were quantified using an SRM (Schoberer Rad Messtechnik) powermeter, and upper limb kinematics were determined using a 10-camera VICON motion capture system. Physiological responses were not significantly affected by crank length. However, greater torque was generated (P < .0005) and peak torque occurred earlier during the push and pull phase (P ≤ .001) in longer cranks. Statistical parametric mapping revealed that the timing and orientation of shoulder flexion, shoulder abduction, and elbow extension were significantly altered in different crank lengths. Despite the biomechanical adaptations, these findings suggest that at constant handgrip speeds (and varying cadence) highly trained handcyclists may select crank lengths between 150 and 180 mm without affecting their physiological performance. Until further research, factors such as anthropometrics, comfort, and self-selected cadence should be used to facilitate crank length selection in recumbent handcyclists.

Horizontal Crank Position Affects Economy and Upper Limb Kinematics of Recumbent Handcyclists.

PURPOSE: To determine the effects of horizontal crank position on economy and upper limb kinematics in recumbent handcycling. METHODS: Fifteen trained handcyclists performed trials at 50% and 70% of their peak aerobic power output (POPeak), determined during a maximal exercise test, in each horizontal crank position. Four horizontal crank positions, 94%, 97%, 100%, and 103% of arm length, were investigated. Horizontal crank positions were defined as the distance between the acromion angle to the center of the handgrip, while the crank arm was parallel to the floor and pointing away from the participant. Economy and upper limb kinematics were calculated during the final minute of each 3-min trial. RESULTS: Horizontal crank position significantly affected handcycling economy at 70% POPeak (P < 0.01) but not at 50% POPeak (P = 0.44). The 97% horizontal crank position (16.0 [1.5] mL·min·W) was significantly more economical than the 94% (16.7 (1.9) mL·min·W) (P = 0.04) and 103% (16.6 (1.7) mL·min·W) (P < 0.01) positions. The 100% horizontal crank position (16.2 (1.7) mL·min·W) was significantly more economical than the 103% position (P < 0.01). Statistical parametric mapping indicated that an increase in horizontal crank position, from 94% to 103%, caused a significant increase in elbow extension, shoulder flexion, adduction, internal rotation, scapular internal rotation, wrist flexion, clavicle depression and clavicle protraction between 0% and 50% (0°-180°) of the cycle (P < 0.05). CONCLUSIONS: Positioning the cranks at 97% to 100% of the athletes' arm length improved handcycling economy at 70% POPeak as, potentially, the musculature surrounding the joints of the upper limb were in a more favorable position to produce force economically.

Shoulder and thorax kinematics contribute to increased power output of competitive handcyclists.

Current knowledge of recumbent handbike configuration and handcycling technique is limited. The purpose of this study was to evaluate and compare the upper limb kinematics and handbike configurations of recreational and competitive recumbent handcyclists, during sport-specific intensities. Thirteen handcyclists were divided into two significantly different groups based on peak aerobic power output (POpeak ) and race experience; competitive (n = 7; 5 H3 and 2 H4 classes; POpeak : 247 ± 20 W) and recreational (n = 6; 4 H3 and 2 H4 classes; POpeak : 198 ± 21 W). Participants performed bouts of exercise at training (50% POpeak ), competition (70% POpeak ), and sprint intensity while three-dimensional kinematic data (thorax, scapula, shoulder, elbow, and wrist) were collected. Statistical parametric mapping was used to compare the kinematics of competitive and recreational handcyclists. Handbike configurations were determined from additional markers on the handbike. Competitive handcyclists flexed their thorax (~5°, P < 0.05), extended their shoulder (~10°, P < 0.01), and posteriorly tilted their scapular (~15°, P < 0.05) more than recreational handcyclists. Differences in scapular motion occurred only at training intensity while differences in shoulder extension and thorax flexion occurred both at training and competition intensities. No differences were observed during sprinting. No significant differences in handbike configuration were identified. This study is the first to compare the upper limb kinematics of competitive recreational handcyclists at sport-specific intensities. Competitive handcyclists employed significantly different propulsion strategies at training and competition intensities. Since no differences in handbike configuration were identified, these kinematic differences could be due to technical training adaptations potentially optimizing muscle recruitment or force generation of the arm.

A systematic review of the discriminating biomechanical parameters during the single leg squat.

OBJECTIVE: To determine whether there are common biomechanical parameters when analysing the single leg squat movement to compare pathological and non-pathological groups and whether these parameters are able to effectively distinguish between groups. METHODS: Five electronic databases were searched using MESH terms, keywords and phrases across four constructs: squat, biomechanical measures, region of interest, study design. Studies were selected based on inclusion of a quantitative biomechanical measure, compared between a pathological and a non-pathological group, and participants performed a single leg squat movement. RESULTS: Fifteen studies were included and reviewed, where the majority of studies investigated patellofemoral pain. There was considerable variation in the biomechanical outcome measure used to compare between groups. The frontal plane projection angle was the most commonly reported measure. There was considerable variation in the manner in which the single leg squat was performed. CONCLUSION: Due to variation in how the single leg squat was performed, it was not possible to determine specific biomechanical parameters that distinguish between pathological and non-pathological groups. Frontal plane projection angle appeared to be a parameter that could be effectively utilised. Standardisation of the single leg squat movement is needed to allow comparison between studies of pathological and non-pathological groups.

Accuracy of movement quality screening to document effects of neuromuscular control retraining exercises in a young ex-footballer with hip and groin symptoms: A proof of concept case study.

Hip and groin pain is common in footballers and altering movement patterns can reduce symptoms. Observational tests of movement control are thought to identify abnormal movement patterns, but their accuracy needs yet to be confirmed by comparison with an objective measure. To assess the accuracy, using 3D motion analysis, of observational movement control tests and their ability to detect changes, and document changes in symptoms following a neuromuscular control exercise programme in an ex-footballer with hip and groin pain. A 25-year-old male with chronic bilateral hip and groin pain had their movement control ability rated and kinematic data collected using 3D motion analysis while performing Small Knee Bend (SKB) and SKB with Rotation (SKB Rot) tests pre-and post-neuromuscular control exercise training. Movement control was rated as at fault if they were unable to control specific trunk and pelvic movements during the tests. The Copenhagen Hip and Groin Outcome Score (HAGOS) was used to assess symptoms. Following the intervention, observational rating during the SKB test improved from fault to no fault for anterior pelvic tilt, which decreased by 17° and 16° during right and left leg SKB tests respectively. The HAGOS symptoms subsection improved from 36% to 61%. Observational movement screening ratings were supported by 3-D motion analysis. These findings indicate that the screening tool was accurate for detecting improvements in trunk and pelvic movement control following an exercise programme in an ex-footballer who had presented with hip and groin pain.

Scapular kinematics in professional wheelchair tennis players.

BACKGROUND: Participating in wheelchair tennis increases the demands placed on the shoulder and could increase the risk of developing shoulder pain and injury that might be associated with differences in scapular kinematics. The aim of the study was to examine the presence of shoulder pain and scapular kinematics in professional wheelchair tennis players. METHOD: Scapular kinematics were obtained in 11 professional wheelchair tennis players, 16 people with shoulder impingement and 16 people without shoulder impingement during humeral elevation and lowering. Clinical examination of the wheelchair tennis players was undertaken using the Wheelchair Users Shoulder Disability Index (WUSPI) and clinical signs of shoulder impingement. FINDINGS: The WUSPI questionnaire (mean = 28 SD 13.8) demonstrated wheelchair tennis participants experienced little shoulder pain and clinical examination revealed negative impingement tests. Wheelchair tennis players had greater scapular posterior tilt during humeral elevation (3.9° SE 1.71; P = 0.048) and lowering (4.3° SE 1.8; P = 0.04) on the dominant compared to non-dominant side. The dominant scapulae of wheelchair tennis players were significantly (P = 0.014) more upwardly rotated (21° SD 6.7) than the scapulae of people with shoulder impingement (14.1° SD 7.0) during scapular plane humeral elevation. INTERPRETATION: This first study of scapular kinematics in professional wheelchair tennis athletes demonstrated bilateral asymmetries and differences to able-bodied participants with shoulder impingement. Understanding the role of sport participation on shoulder function in wheelchair users would assist in the development of preventative and treatment exercise programmes for wheelchair users at risk of shoulder injury and pain.

Measurement of dynamic scapular kinematics using an acromion marker cluster to minimize skin movement artifact.

The measurement of dynamic scapular kinematics is complex due to the sliding nature of the scapula beneath the skin surface. The aim of the study was to clearly describe the acromion marker cluster (AMC) method of determining scapular kinematics when using a passive marker motion capture system, with consideration for the sources of error which could affect the validity and reliability of measurements. The AMC method involves placing a cluster of markers over the posterior acromion, and through calibration of anatomical landmarks with respect to the marker cluster it is possible to obtain valid measurements of scapular kinematics. The reliability of the method was examined between two days in a group of 15 healthy individuals (aged 19-38 years, eight males) as they performed arm elevation, to 120°, and lowering in the frontal, scapular and sagittal planes. Results showed that between-day reliability was good for upward scapular rotation (Coefficient of Multiple Correlation; CMC = 0.92) and posterior tilt (CMC = 0.70) but fair for internal rotation (CMC = 0.53) during the arm elevation phase. The waveform error was lower for upward rotation (2.7° to 4.4°) and posterior tilt (1.3° to 2.8°), compared to internal rotation (5.4° to 7.3°). The reliability during the lowering phase was comparable to results observed during the elevation phase. If the protocol outlined in this study is adhered to, the AMC provides a reliable measurement of upward rotation and posterior tilt during the elevation and lowering phases of arm movement.

Effect of Trunk Support on Upper Extremity Function in People With Chronic Stroke and People Who Are Healthy.

BACKGROUND: Trunk control is thought to contribute to upper extremity (UE) function. However, this common assumption in neurorehabilitation has not been validated in clinical trials. OBJECTIVE: The study objectives were to investigate the effect of providing external trunk support on trunk control and UE function and to examine the relationship between trunk control and UE function in people with chronic stroke and people who were healthy. DESIGN: A cross-sectional study was conducted. METHODS: Twenty-five people with chronic stroke and 34 people who were healthy and matched for age and sex were recruited. Trunk control was assessed with the Trunk Impairment Scale (TIS), and UE impairment and UE function were assessed with the UE subsection of the Fugl-Meyer Assessment (FMA-UE) and the Streamlined Wolf Motor Function Test (SWMFT), respectively. The TIS and SWMFT were evaluated, with and without external trunk support; the FMA-UE was evaluated without trunk support. RESULTS: With trunk support, people with stroke showed improvement from 18 to 20 points on the TIS, a reduction in SWMFT performance times from 37.20 seconds to 35.37 seconds for the affected UE, and improvement from 3.3 points to 3.4 points on the SWMFT Functional Ability Scale for the function of the affected UE. With trunk support, the SWMFT performance time for people who were healthy was reduced from 1.61 seconds to 1.48 seconds for the dominant UE and from 1.71 seconds to 1.59 seconds for the nondominant UE. A significant moderate correlation was found between the TIS and the FMA-UE (r=.53) for people with stroke. LIMITATIONS: The limitations included a nonmasked assessor and a standardized height of the external trunk support. CONCLUSIONS: External trunk support improved trunk control in people with chronic stroke and had a statistically significant effect on UE function in both people with chronic stroke and people who were healthy. The findings suggest an association between trunk control and the UE when external trunk support was provided and support the hypothesis that lower trunk and lumbar stabilization provided by external support enables an improvement in the ability to use the UE for functional activities.