Requirements for home-based upper extremity rehabilitation using wearable motion sensors for stroke patients: a user-centred approach

PURPOSE

Telerehabilitation systems have the potential to enable therapists to monitor and assist stroke patients in achieving high-intensity upper extremity exercise in the home environment. We adopted an iterative user-centred approach, including multiple data sources and meetings with end-users and stakeholders to define the user requirements for home-based upper extremity rehabilitation using wearable motion sensors for subacute stroke patients.

METHODS

We performed a requirement analysis consisting of the following steps: 1) context & groundwork; 2) eliciting requirements; 3) modelling & analysis; 4) agreeing requirements. During these steps, a pragmatic literature search, interviews and focus groups with stroke patients, physiotherapists and occupational therapists were performed. The results were systematically analysed and prioritised into "must-haves", "should-haves", and "could-haves".

RESULTS

We formulated 33 functional requirements: eighteen must-have requirements related to blended care (2), exercise principles (7), exercise delivery (3), exercise evaluation (4), and usability (2); ten should-haves; and five could-haves. Six movement components, including twelve exercises and five combination exercises, are required. For each exercise, appropriate exercise measures were defined.

CONCLUSION

This study provides an overview of functional requirements, required exercises, and required exercise measures for home-based upper extremity rehabilitation using wearable motion sensors for stroke patients, which can be used to develop home-based upper extremity rehabilitation interventions. Moreover, the comprehensive and systematic requirement analysis used in this study can be applied by other researchers and developers when extracting requirements for designing a system or intervention in a medical context.

Stroke patients' motivation for home-based upper extremity rehabilitation with eHealth tools

PURPOSE

eHealth-based exercise therapies were developed to increase stroke patients' adherence to home-based motor rehabilitation. However, these eHealth tools face a rapid decrease in use after a couple of weeks. This study investigates stroke patients' motivation for home-based upper extremity rehabilitation with eHealth tools and their relation with Basic Psychological Needs.

MATERIALS AND METHODS

This is a qualitative study using thematic analysis. We conducted semi-structured interviews with stroke patients with upper extremity motor impairments, who were discharged home from a rehabilitation centre, after they interacted with a novel eHealth coach demonstrator in their homes for five consecutive days.

RESULTS

We included ten stroke patients. Thematic analysis resulted in eight themes for home-based rehabilitation motivation: Curiosity, Rationale, Choice, Optimal challenge, Reference, Encouragement, Social Support and Trustworthiness. Those themes are embedded into three Basic Psychological Needs: "Autonomy", "Competence", and "Relatedness".

CONCLUSION

Eight motivational themes related to the three Basic Psychological Needs describe stroke patients' motivation for home-based upper extremity rehabilitation. We recommend considering those themes when developing a home-based eHealth intervention for stroke patients to increase the alignment of eHealth tools to the patient's needs and reduce motivational decreases in home-based rehabilitation.

Quantifying Quality of Reaching Movements Longitudinally Post-Stroke: A Systematic Review

Background

Disambiguation of behavioral restitution from compensation is important to better understand recovery of upper limb motor control post-stroke and subsequently design better interventions. Measuring quality of movement (QoM) during standardized performance assays and functional tasks using kinematic and kinetic metrics potentially allows for this disambiguation.

Objectives

To identify longitudinal studies that used kinematic and/or kinetic metrics to investigate post-stroke recovery of reaching and assess whether these studies distinguish behavioral restitution from compensation.

Methods

A systematic literature search was conducted using the databases PubMed, Embase, Scopus, and Wiley/Cochrane Library up to July 1st, 2020. Studies were identified if they performed longitudinal kinematic and/or kinetic measurements during reaching, starting within the first 6 months post-stroke.

Results

Thirty-two longitudinal studies were identified, which reported a total of forty-six different kinematic metrics. Although the majority investigated improvements in kinetics or kinematics to quantify recovery of QoM, none of these studies explicitly addressed the distinction between behavioral restitution and compensation. One study obtained kinematic metrics for both performance assays and a functional task.

Conclusions

Despite the growing number of kinematic and kinetic studies on post-stroke recovery, longitudinal studies that explicitly seek to delineate between behavioral restitution and compensation are still lacking in the literature. To rectify this situation, future studies should measure kinematics and/or kinetics during performance assays to isolate restitution and during a standardized functional task to determine the contributions of restitution and compensation.

Reducing the number of test items of the Action Research Arm Test post stroke: A decision tree analysis

Objective - The present study aimed to create a shorter version of the Action Research Arm Test (ARAT) without compromising its measurement properties. Design - Secondary analysis of stroke recovery cohorts that used the ARAT to measure upper-limb impairment. Setting - Rehabilitation centers. Participants - Patients with stroke from five different stroke recovery cohorts. Interventions - Not applicable. Main Outcome Measures - A decision tree version of the ARAT (ARAT-DT) was developed using Chi-squared Automated Interaction Detection (CHAID). In an independent validation subset, criterion validity, agreement of ARAT-DT with original ARAT scores and score categories, and construct validity with the Fugl-Meyer upper extremity (FM-UE) score were determined. Results - In total, 3738 ARAT measurements were available involving 1,425 subjects. CHAID analysis in the development subset (n=2803) revealed an optimized decision tree with a maximum of four consecutive items. In the validation dataset (n=935), the ARAT-DT differed by a mean of 0.19 points (0.3% of the total scale) from the original ARAT scores (limits of agreement: -5.67 to 6.05). The ARAT-DT demonstrated excellent criterion validity with the original ARAT scores (ICC=0.99 and ρ=0.99) and scoring categories (κ_w=0.97). The ARAT-DT showed very good construct validity with the FM-UE motor scale (ρ=0.92). Conclusion - A decision tree version of the ARAT was developed, reducing the maximum number of items necessary for ARAT administration from 19 to 4. The scores produced by the decision tree had excellent criterion validity with original ARAT scores.

Association between malnutrition and stages of sarcopenia in geriatric rehabilitation inpatients: RESORT

BACKGROUND & AIMS

Malnutrition and sarcopenia coexist in older adults, yet they remain largely undiagnosed and untreated, despite available interventions. This study aimed to assess the prevalence, the coexistence of, and the association between malnutrition and sarcopenia in geriatric rehabilitation inpatients.

METHODS

REStORing health of acutely unwell adulTs (RESORT) is an observational, longitudinal cohort of geriatric rehabilitation inpatients. The association between malnutrition, diagnosed according to the Global Leadership Initiative on Malnutrition (GLIM) criteria and sarcopenia according to the revised definition of the European Working Group on Sarcopenia in Older People (EWGSOP2) (no sarcopenia, probable sarcopenia, confirmed sarcopenia and severe sarcopenia) was determined using multinomial logistic regression analyses, adjusted for age, sex, comorbidities and cognitive impairment.

RESULTS

Out of 506 geriatric rehabilitation inpatients, 51% were malnourished, 49% had probable sarcopenia, 0.4% had confirmed sarcopenia (non-severe) and 19% had severe sarcopenia. Malnutrition and probable sarcopenia and malnutrition and confirmed/severe sarcopenia coexisted in 23% and 13% of the 506 patients respectively. Malnutrition was not associated with probable sarcopenia (OR = 0.91, 95% CI = 0.58-1.42, p = 0.674) but with severe sarcopenia (OR = 2.07, 95% CI = 1.13-3.81, p = 0.019).

CONCLUSION

The prevalence, coexistence of, and the association between malnutrition and severe sarcopenia in geriatric rehabilitation inpatients warrant diagnosis at admission. Further research into feasible and effective interventions to counteract both conditions to improve geriatric rehabilitation outcomes is needed.

Are computed tomography-based measures of specific abdominal muscle groups predictive of adverse outcomes in older cancer patients?

PURPOSE

It is unknown whether computed tomography (CT)-based total abdominal muscle measures are representative of specific abdominal muscle groups and whether analysis of specific abdominal muscle groups are predictive of the risk of adverse outcomes in older cancer patients.

METHODS

Retrospective single-center cohort study in elective colon cancer patients aged ≥65 years. CT-based skeletal muscle (SM) surface area, muscle density and intermuscular adipose tissue (IMAT) surface area were determined for rectus abdominis; external- and internal oblique and transversus abdominis (lateral muscles); psoas; and erector spinae and quadratus lumborum (back muscles). Outcomes were defined as severe postoperative complications (Clavien-Dindo score >2) and long-term survival (median follow-up 5.2 years).

RESULTS

254 older colon cancer patients were included (median 73.6 years, 62.2% males). Rectus abdominis showed the lowest SM surface area and muscle density and the back muscles showed the highest IMAT surface area. Psoas muscle density, and lateral muscle density and percentage IMAT were associated with severe postoperative complications independent of gender, age and cancer stage.

CONCLUSIONS

CT-based total abdominal muscle quantity and quality do not represent the heterogeneity that exists between specific muscle groups. The potential added value of analysis of specific muscle groups in predicting adverse outcomes in older (colon) cancer patients should be further addressed in prospective studies.

How does upper extremity Fugl-Meyer motor score relate to resting-state EEG in chronic stroke? A power spectral density analysis

OBJECTIVE

We investigated the potential added value of high-density resting-state EEG by addressing differences with healthy individuals and associations with Fugl-Meyer motor assessment of the upper extremity (FM-UE) scores in chronic stroke.

METHODS

Twenty-one chronic stroke survivors with initial upper limb paresis and eleven matched controls were included. Group differences regarding resting-state EEG parameters (Delta Alpha ratio (DAR) and pairwise-derived Brain Symmetry Index (BSI)) and associations with FM-UE were investigated, as well as lateralization of BSI and the value of different frequency bands.

RESULTS

Chronic stroke survivors showed higher BSI compared to controls (p < 0.001), most pronounced in delta and theta frequency bands (p < 0.0001; p < 0.001). In the delta and theta band, BSI was significantly negatively associated with FM-UE (both p = 0.008) corrected for confounding factors. DAR showed no differences between groups nor association with FM-UE. Directional BSI showed increased power in the affected versus the unaffected hemisphere.

CONCLUSIONS

Asymmetry in spectral power between hemispheres was present in chronic stroke, most pronounced in low frequencies and related to upper extremity motor function deficit.

SIGNIFICANCE

BSI is related to motor impairment and higher in chronic stroke patients compared to healthy controls, suggesting that BSI may be a marker of selective motor control.

Association of Handgrip Strength and Muscle Mass with Dependency in (Instrumental) Activities of Daily Living in Hospitalized Older Adults -The EMPOWER Study

OBJECTIVES

Handgrip strength (HGS) and muscle mass are strong predictors for dependency in Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) in community dwelling older adults. Whether this also applies to older hospitalized patients is yet unknown. We studied the association between HGS and muscle mass with ADL and IADL dependency at admission and change of ADL and IADL dependency at three months after discharge in older hospitalized patients.

DESIGN

Observational longitudinal inception cohort (EMPOWER) including 378 patients aged 70 years and older.

SETTING

Four different clinical wards of a university teaching hospital, The Netherlands.

MEASUREMENTS

HGS and muscle mass were measured within 48 hours after admission using hand dynamometry and Bio-electrical Impedance Analysis respectively. ADL dependency was assessed using the Katz score (0-6 points) and IADL dependency using the Lawton and Brody score (0-8 points) within 48 hours after admission and three months after discharge.

RESULTS

At admission, lower HGS was associated with ADL dependency in both males and females. Lower muscle mass was associated with ADL dependency in males. Lower HGS was associated with IADL dependency, but only in males. Lower HGS at admission in males was associated with an increase in ADL dependency three months after discharge.

CONCLUSION

In hospitalized older patients, HGS is associated with ADL and IADL and muscle mass measures with ADL in male patients only. HGS should be explored as predictive marker for outcome of hospitalized older patients after discharge.

Single Physical Performance Measures Cannot Identify Geriatric Outpatients with Sarcopenia

Background

Sarcopenia is highly prevalent in the older population and is associated with several adverse health outcomes. Equipment to measure muscle mass and muscle strength to diagnose sarcopenia is often unavailable in clinical practice due to the related expenses while an easy physical performance measure to identify individuals who could potentially have sarcopenia is lacking.

Objectives

This study aimed to assess the association between physical performance measures and definitions of sarcopenia in a clinically relevant population of geriatric outpatients.

Design, setting and participants

A cross-sectional study was conducted, consisting of 140 community-dwelling older adults that were referred to a geriatric outpatient clinic. No exclusion criteria were applied.

Measurements

Physical performance measures included balance tests (sideby- side, semi-tandem and tandem test with eyes open and -closed), four-meter walk test, timed up and go test, chair stand test, handgrip strength and two subjective questions on mobility. Direct segmental multi-frequency bioelectrical impedance analysis was used to measure muscle mass. Five commonly used definitions of sarcopenia were applied. Diagnostic accuracy was determined by sensitivity, specificity and area under the curve.

Results

Physical performance measures, i.e. side-by-side test, tandem test, chair stand test and handgrip strength, were associated with at least one definition of sarcopenia. Diagnostic accuracy of these physical performance measures was poor.

Conclusions

Single physical performance measures could not identify older individuals with sarcopenia, according to five different definitions of sarcopenia.

Muscle Measures and Nutritional Status at Hospital Admission Predict Survival and Independent Living of Older Patients - the EMPOWER Study

OBJECTIVES

Older adults with sarcopenia and malnutrition are at risk for co-morbidities, hospitalization, institutionalization, and mortality. In case of hospitalization, risks may be further increased, especially in case of suboptimal dietary intake. The aim of our study was to assess whether muscle mass, muscle strength, functional performance, and nutritional status at hospital admission were associated with survival and independent living among older patients three months after discharge.

DESIGN, SETTING, PARTICIPANTS

The EMPOWER study was an observational, prospective and longitudinal inception cohort of patients older than 70 years admitted to the VU University Medical Centre in Amsterdam, the Netherlands.

MEASUREMENTS

Patients were assessed for demographic and clinical characteristics, measurements of muscle mass (by bioelectrical impedance analysis), handgrip strength (by dynamometry), functional performance (self-reported ability to walk), and screened for risk of malnutrition (by SNAQ). Three months after hospital discharge, survival and living situation were assessed by a follow-up telephone interview.

RESULTS

The majority of the 378 patients enrolled were living independently at the time of hospitalization (90%) and three months post-discharge (83%). Fifty-two patients died in the period from hospital admission to three months after discharge (survival rate 86%). Higher absolute muscle mass measures and not being malnourished at admission were significantly associated with the likelihood of survival. Handgrip strength and self-reported ability to walk were positively associated with a higher chance of living independently three months after discharge, but not with survival.

CONCLUSIONS

Older patients with greater muscle mass and without malnutrition at hospital admission had a higher survival rate, while measures of muscle strength and functional performance were predictive for living independently three months after hospital discharge. Different components of muscle health relate to different relevant outcomes and therefore require investigation of specifically targeted interventions in the hospitalized older population.

Effect of calendar age on physical performance: A comparison of standard clinical measures with instrumented measures in middle-aged to older adults

BACKGROUND

Decline in physical performance is highly prevalent during aging. Identification of sensitive markers of age-related changes in physical performance is important for early detection, development of therapeutic strategies and insight into underlying mechanisms. We studied the association of calendar age and familial longevity with standard clinical and instrumented measures of physical performance in a cohort of healthy middle-aged to older adults.

METHODS

Cross-sectional analysis within the Leiden Longevity Study consisting of offspring of nonagenarian siblings and their partners (n=300, mean age (SD) 65.3 (6.7) years). Standard clinical measures were 25-meter walking speed and total duration of the chair stand test (CST). Instrumented measures were determined using a body fixed sensor. Dependence of physical performance on calendar age and familial longevity (offspring versus partner status) was analyzed using linear and logistic regression, respectively, adjusted for gender and height.

RESULTS

Higher calendar age was associated with slower walking speed and longer duration of the CST (standardized β (95% CI) -.024 (-.042; -.006) and .035 (.014;.056), respectively). Instrumented measures showed similar effect sizes with strongest associations for gait stability and symmetry in mediolateral direction and for the extension and flexion phase of sit-to-stand and stand-to-sit transfers, respectively. No differences were observed between offspring of nonagenarian siblings and their partners.

CONCLUSIONS

Standard clinical and instrumented measures of physical performance are associated with similar effect size to age-related changes in physical performance observable from middle age. The potential added value of instrumented measures for understanding underlying mechanisms requires further attention.

Adaptation of multijoint coordination during standing balance in healthy young and healthy old individuals

Standing balance requires multijoint coordination between the ankles and hips. We investigated how humans adapt their multijoint coordination to adjust to various conditions and whether the adaptation differed between healthy young participants and healthy elderly. Balance was disturbed by push/pull rods, applying two continuous and independent force disturbances at the level of the hip and between the shoulder blades. In addition, external force fields were applied, represented by an external stiffness at the hip, either stabilizing or destabilizing the participants' balance. Multivariate closed-loop system-identification techniques were used to describe the neuromuscular control mechanisms by quantifying the corrective joint torques as a response to body sway, represented by frequency response functions (FRFs). Model fits on the FRFs resulted in an estimation of time delays, intrinsic stiffness, reflexive stiffness, and reflexive damping of both the ankle and hip joint. The elderly generated similar corrective joint torques but had reduced body sway compared with the young participants, corresponding to the increased FRF magnitude with age. When a stabilizing or destabilizing external force field was applied at the hip, both young and elderly participants adapted their multijoint coordination by lowering or respectively increasing their neuromuscular control actions around the ankles, expressed in a change of FRF magnitude. However, the elderly adapted less compared with the young participants. Model fits on the FRFs showed that elderly had higher intrinsic and reflexive stiffness of the ankle, together with higher time delays of the hip. Furthermore, the elderly adapted their reflexive stiffness around the ankle joint less compared with young participants. These results imply that elderly were stiffer and were less able to adapt to external force fields.

Serum albumin and muscle measures in a cohort of healthy young and old participants

Consensus on clinically valid diagnostic criteria for sarcopenia requires a systematical assessment of the association of its candidate measures of muscle mass, muscle strength, and physical performance on one side and muscle-related clinical parameters on the other side. In this study, we systematically assessed associations between serum albumin as a muscle-related parameter and muscle measures in 172 healthy young (aged 18-30 years) and 271 old participants (aged 69-81 year) from the European MYOAGE study. Muscle measures included relative muscle mass, i.e., total- and appendicular lean mass (ALM) percentage, absolute muscle mass, i.e., ALM/height(2) and total lean mass in kilograms, handgrip strength, and walking speed. Muscle measures were standardized and analyzed in multivariate linear regression models, stratified by age. Adjustment models included age, body composition, C-reactive protein and lifestyle factors. In young participants, serum albumin was positively associated with lean mass percentage (p = 0.007) and with ALM percentage (p = 0.001). In old participants, serum albumin was not associated with any of the muscle measures. In conclusion, the association between serum albumin and muscle measures was only found in healthy young participants and the strongest for measures of relative muscle mass.

Changes in sensory reweighting of proprioceptive information during standing balance with age and disease

With sensory reweighting, reliable sensory information is selected over unreliable information during balance by dynamically combining this information. We used system identification techniques to show the weight and the adaptive process of weight change of proprioceptive information during standing balance with age and specific diseases. Ten healthy young subjects (aged between 20 and 30 yr) and 44 elderly subjects (aged above 65 yr) encompassing 10 healthy elderly, 10 with cataract, 10 with polyneuropathy, and 14 with impaired balance, participated in the study. During stance, proprioceptive information of the ankles was disturbed by rotation of the support surface with specific frequency content where disturbance amplitude increased over trials. Body sway and reactive ankle torque were measured to determine sensitivity functions of these responses to the disturbance amplitude. Model fits resulted in a proprioceptive weight (changing over trials), time delay, force feedback, reflexive stiffness, and damping. The proprioceptive weight was higher in healthy elderly compared with young subjects and higher in elderly subjects with cataract and with impaired balance compared with healthy elderly subjects. Proprioceptive weight decreased with increasing disturbance amplitude; decrease was similar in all groups. In all groups, the time delay was higher and the reflexive stiffness was lower compared with young or healthy elderly subjects. In conclusion, proprioceptive information is weighted more with age and in patients with cataract and impaired balance. With age and specific diseases the time delay was higher and reflexive stiffness was lower. These results illustrate the opportunity to detect the underlying cause of impaired balance in the elderly with system identification.

Associations between muscle strength, spirometric pulmonary function and mobility in healthy older adults

Pathological obstruction in lungs leads to severe decreases in muscle strength and mobility in patients suffering from chronic obstructive pulmonary disease. The purpose of this study was to investigate the interdependency between muscle strength, spirometric pulmonary functions and mobility outcomes in healthy older men and women, where skeletal muscle and pulmonary function decline without interference of overt disease. A total of 135 69- to 81-year-old participants were recruited into the cross-sectional study, which was performed as a part of European study MyoAge. Full, partial and no mediation models were constructed to assess the interdependency between muscle strength (handgrip strength, knee extension torque, lower extremity muscle power), spirometric pulmonary function (FVC, FEV1 and FEF50) and mobility (6-min walk and Timed Up and Go tests). The models were adjusted for age, sex, total fat mass, body height and site of enrolment. Partial mediation models, indicating both direct and pulmonary function mediated associations between muscle strength and mobility, fitted best to the data. Greater handgrip strength was significantly associated with higher FVC, FEV1 and FEF50 (p < 0.05). Greater muscle power was significantly associated with better performance in mobility tests. Results suggest that decline in mobility with aging may be caused by decreases in both muscle strength and power but also mediated through decreases in spirometric pulmonary function. Future longitudinal studies are warranted to better understand how loss of function and mass of the respiratory muscles will affect pulmonary function among older people and how these changes are linked to mobility decline.

Diagnostic criteria for sarcopenia and physical performance

Relative and absolute muscle mass and muscle strength are used as diagnostic criteria for sarcopenia. We aimed to assess which diagnostic criteria are most associated with physical performance in 180 young (18-30 years) and 281 healthy old participants (69-81 years) of the European study MYOAGE. Diagnostic criteria included relative muscle mass (total or appendicular lean mass (ALM) as percentage of body mass), absolute muscle mass (ALM/height squared and total lean mass), knee extension torque, and handgrip strength. Physical performance comprised walking speed, Timed Up and Go test (TUG), and in a subgroup physical fitness. Diagnostic criteria for sarcopenia and physical performance were standardized, and the associations were analyzed using linear regression models stratified by age category, with adjustments for age, gender, and country. In old participants, relative muscle mass was associated with faster walking speed, faster TUG, and higher physical fitness (all p < 0.001). Absolute muscle mass was not associated with physical performance. Knee extension torque and handgrip strength were associated with faster walking speed (both p ≤ 0.003). Knee extension torque was associated with TUG (p = 0.001). Knee extension torque and handgrip strength were not associated with physical fitness. In young participants, there were no significant associations between diagnostic criteria for sarcopenia and physical performance, except for a positive association between relative muscle mass and physical fitness (p < 0.001). Relative muscle mass, defined as lean mass or ALM percentage, was most associated with physical performance. Absolute muscle mass including ALM/height squared was not associated with physical performance. This should be accounted for when defining sarcopenia.

Diagnostic criteria for sarcopenia relate differently to insulin resistance

Skeletal muscle is important in insulin-stimulated glucose uptake. Sarcopenia is, therefore, a possible risk factor for insulin resistance. Currently, different diagnostic criteria for sarcopenia include low muscle mass, muscle strength, and walking speed. We assessed these muscle characteristics in relation to insulin resistance in nondiabetics. This cross-sectional study included 301 nondiabetics, mean age 65.9 years. Area under curve (AUC) calculations of insulin and glucose from a 2-h oral glucose tolerance test (OGTT) and homeostasis model assessment of insulin resistance (HOMA-IR) were used as measures of insulin resistance. Muscle characteristics were relative muscle mass (total or appendicular lean mass (ALM) as percentage of body mass), absolute muscle mass (ALM/height(2) and total lean mass), handgrip strength, and walking speed. All muscle characteristics were standardized and analyzed in linear regression models, stratified by gender. For both males and females, relative muscle mass was inversely associated with AUC insulin, AUC glucose, and HOMA-IR (ALM percentage all p ≤ 0.004). Absolute muscle mass was positively associated with AUC insulin and HOMA-IR (ALM/height(2) all p < 0.001) but not with AUC glucose. Adjustments for fat mass attenuated aforementioned associations. There were no associations between handgrip strength and insulin resistance. Walking speed was inversely associated with AUC insulin in males (p = 0.032). The association between muscle characteristics and insulin resistance was strongest for relative muscle mass. Diagnostic criteria for sarcopenia relate differently to insulin resistance. The role of muscle tissue as an internal glucose-regulating organ is better reflected by relative muscle mass than by absolute muscle mass, muscle strength, or walking speed.

Defining sarcopenia: the impact of different diagnostic criteria on the prevalence of sarcopenia in a large middle aged cohort

Sarcopenia, low muscle mass, is an increasing problem in our ageing society. The prevalence of sarcopenia varies extremely between elderly cohorts ranging from 7% to over 50%. Without consensus on the definition of sarcopenia, a variety of diagnostic criteria are being used. We assessed the degree of agreement between seven different diagnostic criteria for sarcopenia based on muscle mass and handgrip strength, described in literature. In this cross-sectional study, we included men (n=0325) and women (n=0329) with complete measurements of handgrip strength and body composition values as measured by bioimpedance analysis within the Leiden Longevity Study. Prevalence of sarcopenia was stratified by gender and age. In men (mean age 64.5 years), the prevalence of sarcopenia with the different diagnostic criteria ranged from 0% to 20.8% in the lowest age category (below 60 years), from 0%to 31.2% in the middle (60 to 69 years) and from 0% to 45.2% in the highest age category (above 70 years). In women (mean age 61.8 years), the prevalence of sarcopenia ranged from 0% to 15.6%, 0% to 21.8% and 0% to 25.8% in the lowest, middle and highest age category, respectively. Only one participant (0.2%) was identified having sarcopenia according to all diagnostic criteria that marked prevalence above 0%. We conclude that the prevalence of sarcopenia is highly dependent on the applied diagnostic criteria. It is necessary to reach a consensus on the definition of sarcopenia in order to make studies comparable and for implementation in clinical care.

Spring-like Ankle Foot Orthoses reduce the energy cost of walking by taking over ankle work

In patients with central neurological disorders, gait is often limited by a reduced ability to push off with the ankle. To overcome this reduced ankle push-off, energy-storing, spring-like carbon-composite Ankle Foot Orthoses (AFO) can be prescribed. It is expected that the energy returned by the AFO in late stance will support ankle push-off, and reduce the energy cost of walking. In 10 patients with multiple sclerosis and stroke the energy cost of walking, 3D kinematics, joint power, and joint work were measured during gait, with and without the AFO. The mechanical characteristics of the AFO were measured separately, and used to calculate the contribution of the AFO to the ankle kinetics. We found a significant decrease of 9.8% in energy cost of walking when walking with the AFO. With the AFO, the range of motion of the ankle was reduced by 12.3°, and the net work around the ankle was reduced by 29%. The total net work in the affected leg remained unchanged. The AFO accounted for 60% of the positive ankle work, which reduced the total amount of work performed by the leg by 11.1% when walking with the AFO. The decrease in energy cost when walking with a spring-like energy-storing AFO in central neurological patients is not induced by an augmented net ankle push-off, but by the AFO partially taking over ankle work.

Shoulder pain and external rotation in spastic hemiplegia do not improve by injection of botulinum toxin A into the subscapular muscle

OBJECTIVE

To study the effect of botulinum toxin A in the subscapular muscle on shoulder pain and humerus external rotation.

METHODS

22 stroke patients with spastic hemiplegia, substantial shoulder pain and reduced external rotation of the humerus participated in a randomised, double blind, placebo controlled effect study. Injections of either botulinum toxin A (Botox, 2x50 units) or placebo were applied to the subscapular muscle at two locations. Pain was scored on a 100 mm vertical Visual Analogue Scale; external rotation was recorded by means of electronic goniometry. Assessments were carried out at 0 (baseline), 6 and 12 weeks.

RESULTS

21 patients completed the study. We observed no significant changes in pain or external rotation as a result of administration of botulinum toxin A. External rotation improved significantly (p = 0.001) for both the treatment group (20.4 degrees (16.6) to 32.1 degrees (14.0)) and the control group (10.3 degrees (19.5) to 23.7 degrees (20.7)) as a function of time.

CONCLUSIONS

Application of botulinum toxin A into the subscapular muscle for reduction of shoulder pain and improvement of humeral external rotation in spastic hemiplegia does not appear to be clinically efficacious.

Pathological muscle activation patterns in patients with massive rotator cuff tears, with and without subacromial anaesthetics

A mechanical deficit due to a massive rotator cuff tear is generally concurrent to a pain-induced decrease of maximum arm elevation and peak elevation torque. The purpose of this study was to measure shoulder muscle coordination in patients with massive cuff tears, including the effect of subacromial pain suppression. Ten patients, with MRI-proven cuff tears, performed an isometric force task in which they were asked to exert a force in 24 equidistant intervals in a plane perpendicular to the humerus. By means of bi-polar surface electromyography (EMG) the direction of the maximal muscle activation or principal action of six muscles, as well as the external force, were identified prior to, and after subacromial pain suppression. Subacromial lidocaine injection led to a significant reduction of pain and a significant increase in exerted arm force. Prior to the pain suppression, we observed an activation pattern of the arm adductors (pectoralis major pars clavicularis and/or latissimus dorsi and/or teres major) during abduction force delivery in eight patients. In these eight patients, adductor activation was different from the normal adductor activation pattern. Five out of these eight restored this aberrant activity (partly) in one or more adductor muscles after subacromial lidocaine injection. Absence of glenoid directed forces of the supraspinate muscle and compensation for the lost supraspinate abduction torque by the deltoideus leads to destabilizating forces in the glenohumeral joint, with subsequent upward translation of the humeral head and pain. In order to reduce the superior translation force, arm adductors will be co-activated at the cost of arm force and abduction torque. Pain seems to be the key factor in this (avoidance) mechanism, explaining the observed limitations in arm force and limitations in maximum arm elevation in patients suffering subacromial pathologies. Masking this pain may further deteriorate the subacromial tissues as a result of proximal migration of the humeral head and subsequent impingement of subacromial tissues.

Pathological Teres Major activation in patients with massive rotator cuff tears alters with pain relief and/or salvage surgery transfer

BACKGROUND

Massive rotator cuff tears impose restraints on overhand arm functionality and are often accompanied by pain. After musculotendinous Teres Major transfer, overhand arm function is generally restored and pain is reduced. The assumed mechanical abduction insufficiency and Teres Major muscle function adaptation will be experimentally verified.

METHODS

Principal Teres Major muscle activation (surface IEMG averaged over 3s) is recorded for 12-24 isometric and isotonic force directions perpendicular to the 60 degrees forward flexed humerus in three conditions: prior to surgery (n = 6 patients), prior to surgery and after subacromial anaesthetic (n = 6) and post-surgery (n = 3). Principal direction and on-, offset directions were estimated.

FINDINGS

Teres Major activation adapts both to pathological and post surgery conditions: the normal activation during adduction changes into activation during forward flexion or abduction. Glenohumeral stabilisation, not abduction torque, seems to be the explanation for post surgery Teres Major transfer success.

INTERPRETATIONS

The pathological absence of Supraspinatus and Infraspinatus forces during forward flexion result in increased upward glenohumeral instability. The superior translations are compensated for by Teres Major activity during forward flexion. This translation-'force' function conflicts with the adduction-generating rotation-'torque' function. This may explain the pain-induced reduction of arm elevation in these patients. Musculotendinous transfer solves the force-torque conflict by changing the moment arm of the Teres Major from adduction to abduction. Teres Major can now both compensate for the loss of Supraspinatus and Infraspinatus forces needed for glenohumeral stabilisation and contribute to forward flexion of the arm.

Measurement of three dimensional shoulder movement patterns with an electromagnetic tracking device in patients with a frozen shoulder

OBJECTIVE

To compare three dimensional movement patterns of the affected and non-affected shoulder in patients with a frozen shoulder before and after physical therapy.

METHODS

Patients with a unilateral frozen shoulder were assessed before and after three months of treatment. Three dimensional movement analysis was performed with the "Flock of Birds" electromagnetic tracking device while the patient raised their arms in three directions. Slopes of the regression lines of glenohumeral joint rotation versus scapular rotation, reflecting the scapulohumeral rhythm, were calculated. All assessments were made for both the affected and the unaffected side. Additional assessments included conventional range of motion (ROM) measurements and visual analogue scales (VAS) (0-100 mm) for shoulder pain at rest, during movement, and at night.

RESULTS

Ten patients with a unilateral frozen shoulder were included. The slopes of the curves of the forward flexion, scapular abduction, and abduction in the frontal plane of the affected and the unaffected side were significantly different in all three movement directions. Mean differences were 0.267, 0.215, and 0.464 (all p values <0.005), respectively. Mean changes of the slopes of the affected side after treatment were 0.063 (p=0.202), 0.048 (p=0.169), and 0.264 (p=0.008) in forward flexion, scapular abduction, and abduction in the frontal plane, respectively. All patients showed significant improvement in active ROM (all p<0.005), and the VAS for pain during movement and pain at night (p<0.05).

CONCLUSIONS

With a three dimensional electromagnetic tracking system the abnormal movement pattern of a frozen shoulder, characterised by the relatively early laterorotation of the scapula in relation to glenohumeral rotation during shoulder elevation, can be described and quantified. Moreover, the system is sufficiently sensitive to detect clinical improvements. Its value in other shoulder disorders remains to be established.