A quantitative method of assessing malalignment and joint space loss of the human knee

Malalignment and joint space loss in the arthritic human knee can be measured quantitatively by employing a frame that allows for parallax correction of radiographs taken from the weight bearing lower limb. This standardized method will assist pre-operative planning for osteotomies and post-operative follow-up of patients with surgically re-aligned lower limbs. The procedure requires anatomically important points to be digitized, together with reference points built into the frame. Data are then processed automatically in a desk top computer, and the program provides for an easily understood diagram and listing of characteristic indices of malalignment.     

Axillary artery injury combined with delayed brachial plexus palsy due to compressive hematoma in a young patient: a case report

Aim

To prove the possibility of axillary nerve conduction changes following shoulder subluxation due to hemiplegia, in order to investigate the usefulness of screening nerve conduction studies in patients with hemiplegia for finding peripheral neuropathy.

Methods

Forty-four shoulders of twenty-two patients with a first-time stroke having flaccid hemiplegia were tested, 43 ± 12 days after stroke onset. Wasting and weakness of the deltoid were present in the involved side. Motor nerve conduction latency and compound muscle action potential (CMAP) amplitude were measured along the axillary nerve, comparing the paralyzed to the sound shoulder. The stimulation was done at the Erb's point whilst the recording needle electrode was inserted into the deltoid muscle 4 cm directly beneath the lateral border of the acromion. Wilcoxon signed rank test was used to compare the motor conduction between the sound and the paralytic shoulder. Mann-Whitney test was used to compare between plegic and sound shoulder in each side.

Results

Mean motor nerve conduction latency time to the deltoid muscle was 8.49, SD 4.36 ms in the paralyzed shoulder and 5.17, SD 1.35 ms in the sound shoulder (p < 0.001). Mean compound muscle action potential (CMAP) amplitude was 2.83, SD 2.50 mV in the paralyzed shoulder and was 7.44, SD 5.47 mV in the sound shoulder (p < 0.001). Patients with right paralyzed shoulder compared to patients with right sound shoulder (p < 0.001, 1-sided for latency; p = 0.003, 1-sided for amplitude), and patients with left paralyzed shoulder compared to patients with left sound shoulder (p = 0.011, 1-sided for latency, p = 0.001, 1-sided for amplitude), support the same outcomes. The electro-physiological changes in the axillary nerve may appear during the first six weeks after stroke breakout.

Conclusion

Continuous traction of the axillary nerve, as in hypotonic shoulder, may affect the electro-physiological properties of the nerve. It most probably results from subluxation of the head of the humerus, causing demyelinization and even axonopathy. Slowing of the conduction velocities of the axillary nerve in the paralyzed shoulders may be related also to the lowering of the skin temperature and muscular atrophy in the same limb. The usefulness of routine screening nerve conduction studies in the shoulder of hemiplegic patients seems to be advocated.     

肌内效贴联合经皮神经电刺激对脑卒中后偏瘫肩痛患者肩关节疼痛、肩关节功能和血液流变学的影响

摘要 目的：探讨肌内效贴联合经皮神经电刺激（TENS）对脑卒中后偏瘫肩痛患者肩关节疼痛、肩关节功能和血液流变学的影响。方法：选取2019年5月~2022年1月期间江苏省人民医院收治的脑卒中后偏瘫肩痛患者100例,根据随机数字表法将其分为对照组（n=50）和研究组（n=50）,在常规康复训练的基础上,对照组接受肌内效贴干预,研究组接受肌内效贴联合TENS干预。对比两组视觉模拟评分法（VAS）评分、上肢Fugl-Meyer运动功能评定量表（FMA）、改良Barthel指数（MBI）、Constant-Murley肩关节功能评分量表（CMS）评分、血液流变学指标、肩关节功能变化情况。结果：研究组干预后VAS评分低于同期对照组（P<0.05）。研究组干预后FMA、MBI、CMS评分高于同期对照组（P<0.05）。研究组干预后血浆黏度、纤维蛋白原、全血黏度、红细胞压积均低于同期对照组（P<0.05）。研究组干预后患侧肩关节的外旋、前屈、外展的主动/被动活动度（AROM/PROM）均大于对照组同期（P<0.05）。结论：肌内效贴联合TENS应用于脑卒中后偏瘫肩痛患者,可有效改善肩关节疼痛、肩关节功能和血液流变学。     

Comparison of physiotherapy,manipulation, and corticosteroid injection for treating shoulder complaints in general practice: randomised,single blind study.

OBJECTIVE: To compare the efficacy of physiotherapy, manipulation, and corticosteroid injection for treating patients with shoulder complaints in general practice. DESIGN: Randomised, single blind study. SETTING: Seven general practices in the Netherlands. SUBJECTS: 198 patients with shoulder complaints, of whom 172 were divided, on the basis of physical examination, into two diagnostic groups: a shoulder girdle group (n = 58) and a synovial group (n = 114). INTERVENTIONS: Patients in the shoulder girdle group were randomised to manipulation or physiotherapy, and patients in the synovial group were randomised to corticosteroid injection, manipulation, or physiotherapy. MAIN OUTCOME MEASURES: Duration of shoulder complaints analysed by survival analysis. RESULTS: In the shoulder girdle group duration of complaints was significantly shorter after manipulation compared with physiotherapy (P < 0.001). Also the number of patients reporting treatment failure was less with manipulation. In the synovial group duration of complaints was shortest after corticosteroid injection compared with manipulation and physiotherapy (P < 0.001). Drop out due to treatment failure was low in the injection group (17%) and high in the manipulation group (59%) and physiotherapy group (51%). CONCLUSIONS: For treating shoulder girdle disorders, manipulation seems to be the preferred treatment. For the synovial disorders, corticosteroid injection seems the best treatment.     

Effects of posture,movement and hand load on shoulder muscle activity

The influence of external factors such as arm posture, hand loading and dynamic exertion on shoulder muscle activity is needed to provide insight into the relationship between internal and external loading of the shoulder joint. Surface electromyography was collected from 8 upper extremity muscles on 16 participants who performed isometric and dynamic shoulder exertions in three shoulder planes (flexion, mid-abduction and abduction) covering four shoulder elevation angles (30°, 60°, 90° and 120°). Shoulder exertions were performed under three hand load conditions: no load, holding a 0.5 kg load and 30% grip. It was found that adding a 0.5 kg load to the hand increased shoulder muscle activity by 4% maximum voluntary excitation (MVE), across all postures and velocities. Performing a simultaneous shoulder exertion and hand grip led to posture specific redistribution of shoulder muscle activity that was consistent for both isometric and dynamic exertions. When gripping, anterior and middle deltoid activity decreased by 2% MVE, while posterior deltoid, infraspinatus and trapezius activity increased by 2% MVE and biceps brachii activity increased by 6% MVE. Increased biceps brachii activity with gripping may be an initiating factor for the changes in shoulder muscle activity. The finding that hand gripping altered muscle activation, and thus the internal loading, of the shoulder may play an important role in shoulder injury development and rehabilitation.     

Quadriceps cross-sectional area changes in young healthy men with different magnitude of Q angle

Knee pain and dysfunction have been often associated with an ineffective pull of the patella by the vastus medialis (VM) relative to the vastus lateralis (VL), particularly in individuals with knee joint malalignment. Such changes in muscular behavior may be attributed to muscle inhibition and/or atrophy that precedes the onset of symptoms. The aim of this study was to investigate possible effects of knee joint malalignment, indicated by a high quadriceps (Q) angle (HQ angle >15 degrees ), on the anatomic cross-sectional area (aCSA) of the entire quadriceps and its individual parts, in a group of 17 young asymptomatic men compared with a group of 19 asymptomatic individuals with low Q angle (LQ angle <15 degrees ). The aCSA of the entire quadriceps (TQ), VM, VL, vastus intermedius (VI), rectus femoris (RF), and patellar tendon (PT) were measured during static and dynamic magnetic resonance imaging (MRI) with the quadriceps relaxed and under contraction, respectively. A statistically significant lower aCSA was obtained in the HQ angle group, compared with the LQ angle group, for the TQ, VL, and VI in both static (TQ = 9.9%, VL = 12.9%, and VI = 9.1%; P < 0.05) and dynamic imaging (TQ = 10.7%, P < 0.001; VL = 13.4%, P < 0.01; and VI = 9.8%, P < 0.05) and the aCSA of the VM in dynamic MRI (11.9%; P < 0.01). The muscle atrophy obtained in the HQ angle group may be the result of a protective mechanism that inhibits and progressively adapts muscle behavior to reduce abnormal loading and wear of joint structures.     

MRI in shoulder joint instability

The paper provides the results of MRI studies in 100 patients having complaints of pain and impaired movements in the shoulder joint in order to establish a diagnosis. Sixty-three patients were found to have MRI signs of shoulder joint instability (SJI). The paper presents and states the found MRI symptoms of SJI. The author concludes that MRI of the shoulder joint in its instability should be used appropriately as it may early reveal changes in the articular osseous, cartilaginous, and soft tissues, which is useful in diagnosing and choosing a treatment.     

MRI in shoulder joint instability

The paper provides the results of MRI studies in 100 patients having complaints of pain and impaired movements in the shoulder joint in order to establish a diagnosis. Sixty-three patients were found to have MRI signs of shoulder joint instability (SJI). The paper presents and states the found MRI symptoms of SJI. The authors concludes that MRI of the shoulder joint in its instability should be used appropriately as it may early reveal changes in the articular osseous, cartilaginous, and soft tissues, which is useful in diagnosing and choosing a treatment.     

Clinical Manifestation of Depression after Stroke: Is It Different from Depression in Other Patient Populations?

Background

Despite ample research on depression after stroke, the debate continues regarding whether symptoms such as sleep disturbances, loss of energy, changes in appetite and diminished concentration should be considered to be consequences of stroke or general symptoms of depression. By comparing symptoms in depressed and non-depressed stroke patients with patients in general practice and patients with symptomatic atherosclerotic diseases, we aim to further clarify similarities and distinctions of depression after stroke and depression in other patient populations. Based on this, it is possible to determine if somatic symptoms should be evaluated in stroke patients in diagnosing depression after stroke.

Methods

An observational multicenter study is conducted in three hospitals and seven general practices including 382 stroke patients admitted to hospital with a clinical diagnosis of intracerebral hemorrhage or ischemic infarction, 1160 patients in general practice (PREDICT-NL), and 530 patients with symptomatic atherosclerotic diseases (SMART-Medea).

Results

The prevalence of major depressive disorder according to DSM-IV criteria was 14.1% (95% CI 11.0%-18.0%) in the stroke cohort, 5.4% (95% CI 3.8%-7.9%) in the symptomatic atherosclerotic diseases cohort and 12.9% (95% CI 11.1%-15.0%) in the general practice cohorts. Comparing depressed patients of the three cohorts demonstrated broadly similar symptom profiles, as well as comparable levels of individual symptom prevalence. However, the stroke patients suffered more severely from these symptoms than patients in the other populations.

Conclusions

The findings suggest that depression after stroke is not a different type of depression. This finding indicates that all depressive symptoms should be evaluated in stroke patients, including somatic symptoms.     

Non-Tuberculous Shoulder Disabilities in Sanatorium Patients

Limitation of shoulder movement and/or shoulder pain occurs among patients chronically ill with conditions not related to bones and joints. Thirty patients with 45 disabled shoulders among persons with pulmonary tuberculosis were studied. The condition occurred most frequently in men beyond the age of 38 years. The shoulder involvement was not related to the location or severity of the underlying lung disease. Before the onset of their illness, most of these patients were very active and had well-developed shoulder muscles. The relative inactivity of hospital life may be a causative factor. The condition is reversible with physiotherapy and corticosteroids; 58% in this series recovered completely and 33% improved. Four progressed to a shoulderhand syndrome. Prophylactic shoulder exercises may be effective.     

A study of weekly and seasonal variation of stroke onset

A registry based study was conducted to assess the variation in first-onset stroke with weekdays and seasons, in relation to the effects of age. Between 1 December 1991 and 30 November 1998, 10,729 first-onset stroke patients aged 25 or more were registered in Toyama Prefecture, Japan. We compared the weekly and seasonal variation in first-onset stroke by a one-way goodness-of-fit chi(2)-test. The relationship between seasonal variation in stroke onset and age was also evaluated by the method of Kendall's tau-b R x C tables with ordered categories. The frequency of onset of all strokes and cerebral infarctions (CI) was significantly higher on weekdays than at weekends (P < 0.01). More men had strokes and CI on a Monday (P < 0.01), and more women had cerebral hemorrhage (CH) on a Monday and CI at the end of the week. Stroke incidence was higher in patients aged less than 60 years (20.6%) than in those aged 60 years or over (18.7%) on a Monday compared to the weekend. By chi(2)-test, comparing observed with expected numbers of stroke onsets, weighted by the number of days in each 3-month period, the incidence of all strokes, CI and CH was significantly higher in winter and spring than in summer. The seasonal variation in the onset of stroke declined with age: all strokes (P < 0.001) and CH (P < 0.001) in both genders; subarachnoid hemorrhage (P < 0.001) only in men. Our study shows that the onset of stroke is more frequent on weekdays than on weekends, and may be associated with changes in psychophysiological stresses between working days and the weekend. We also observed a clear negative dose response relationship between seasonal variations in occurrence and age. It may be speculated that younger people have more change to work outdoors, exposing themselves to the winter environment. Their lifestyle and physiological condition may be different from those of older people.     

Glenohumeral joint dynamics and shoulder muscle activity during geared manual wheelchair propulsion on carpeted floor in individuals with spinal cord injury

This study investigated the effects of using geared wheels on glenohumeral joint dynamics and shoulder muscle activity during manual wheelchair propulsion. Seven veterans with spinal cord injury propelled their wheelchairs equipped with geared wheels over a carpeted floor in low gear (1.5:1) and standard gear (1:1) conditions. Hand-rim kinetics, glenohumeral joint dynamics, and muscle activity were measured using a custom instrumented geared wheel, motion analysis, and surface electromyography. Findings indicated that the propulsion speed and stroke distance decreased significantly during the low gear condition. The peak hand-rim resultant force and propulsive moment, as well as the peak glenohumeral inferior force and flexion moment, were significantly less during the low gear condition. The peak and integrated muscle activity of the anterior deltoid and pectoralis major decreased significantly, while the normalized integrated muscle activity (muscle activity per stroke distance) was not significantly different between the two conditions. Propulsion on carpeted floor in the low gear condition was accompanied by a reduced perception of effort. The notable decrease in the peak shoulder loading and muscle activity suggests that usage of geared wheels may be beneficial for wheelchair users to enhance independent mobility in their homes and communities while decreasing their shoulder demands.     

The Impact of Early Specialist Management on Outcomes of Patients with In-Hospital Stroke

Delays in treatment of in-hospital stroke (IHS) adversely affect patient outcomes. We hypothesised that early referral and specialist management of IHS patients will improve outcomes at 90 days. Baseline characteristics, assessment delays, thrombolysis eligibility, 90-day functional outcomes and all-cause mortality were compared between IHS patients referred for specialist stroke management within 3 hours of symptom onset (early referrals) and later referrals. Patients were identified from a prospective stroke registry between January 2009 and December 2010. Inclusion criteria were primary admission with a non-stroke diagnosis, onset of new neurological deficits after admission and early ischaemic changes on CT or MR imaging. Eighty four (4.6%) of 1836 stroke patients had IHS (mean age 74 year; 51% male, median NIHSS score 10). There were no significant differences in baseline characteristics between 53 (63%) early and 31 (37%) late referrals. Thrombolysis was performed in 29 (76%) of the 37/78 (47%) potentially eligible patients; 7 patients were excluded because specialist referral was delayed beyond 4.5 hours despite symptom recognition within 3 hours of onset. Early referral improved functional outcomes (modified Rankin Scale 0–2 at 90 days 40% v 7%, p = 0.001) and was an independent predictor of mRS 0–2 at 90 days after adjusting for age, pre-morbid function, primary cause for hospital admission and stroke severity [OR 1.13 (95% C.I.  = 1.10–1.27), p = 0.002]. Early referral and specialist management of IHS patients that includes thrombolysis is associated with better functional outcomes at 90 days.     

Clinico-radiological analysis of surgically treated sciatica cases

An analysis included 187 patients treated surgically for sciatica due to vertebral disk pathologies. Nerve roots compression was noted in all examined patients, including 54% of left-sided compression, 43% of right-sided, and 3% of bilateral compression. Majority of cases involved nerve roots in L5 (51%) and L4 (36%) segments of the spine. Intra-operationally 139 (87%) out of 160 abnormal radiculographies have been confirmed. Disk disease was diagnosed in 11 patients despite the lack of changes in radiculography. It may be explained by the extremely lateral prolapse of the vertebral disk. Long term course of the disease and clinical picture decide on surgery in such cases.     

Arm-plane representation of shoulder compensation during pointing movements in patients with stroke

Improvements in functional motor activities are often accompanied by motor compensations to overcome persistent motor impairment in the upper limb. Kinematic analysis is used to objectively quantify movement patterns including common motor compensations such as excessive trunk displacement during reaching. However, a common motor compensation to assist reaching, shoulder abduction, is not adequately characterized by current motion analysis approaches. We apply the arm-plane representation that accounts for the co-variation between movements of the whole arm, and investigate its ability to identify and quantify compensatory arm movements in stroke subjects when making forward arm reaches. This method has not been previously applied to the analysis of motion deficits. Sixteen adults with right post-stroke hemiparesis and eight healthy age-matched controls reached in three target directions (14 trials/target; sampling rate: 100 Hz). Arm-plane movement was validated against endpoint, joint, and trunk kinematics and compared between groups. In stroke subjects, arm-plane measures were correlated with arm impairment (Fugl-Meyer Assessment) and ability (Box and Blocks) scores and were more sensitive than clinical measures to detect mild motor impairment. Arm-plane motion analysis provides new information about motor compensations involving the co-variation of shoulder and elbow movements that may help to understand the underlying motor deficits in patients with stroke.     

Infarction in the territory of the anterior cerebral artery: clinical study of 51 patients

Background

Little is known about clinical features and prognosis of patients with ischaemic stroke caused by infarction in the territory of the anterior cerebral artery (ACA). This single centre, retrospective study was conducted with the following objectives: a) to describe the clinical characteristics and short-term outcome of stroke patients with ACA infarction as compared with that of patients with ischaemic stroke due to middle cerebral artery (MCA) and posterior cerebral artery (PCA) infarctions, and b) to identify predictors of ACA stroke.

Methods

Fifty-one patients with ACA stroke were included in the "Sagrat Cor Hospital of Barcelona Stroke Registry" during a period of 19 years (1986–2004). Data from stroke patients are entered in the stroke registry following a standardized protocol with 161 items regarding demographics, risk factors, clinical features, laboratory and neuroimaging data, complications and outcome. The characteristics of these 51 patients with ACA stroke were compared with those of the 1355 patients with MCA infarctions and 232 patients with PCA infarctions included in the registry.

Results

Infarctions of the ACA accounted for 1.3% of all cases of stroke (n = 3808) and 1.8% of cerebral infarctions (n = 2704). Stroke subtypes included cardioembolic infarction in 45.1% of patients, atherothrombotic infarction in 29.4%, lacunar infarct in 11.8%, infarct of unknown cause in 11.8% and infarction of unusual aetiology in 2%. In-hospital mortality was 7.8% (n = 4). Only 5 (9.8%) patients were symptom-free at hospital discharge. Speech disturbances (odds ratio [OR] = 0.48) and altered consciousness (OR = 0.31) were independent variables of ACA stroke in comparison with MCA infarction, whereas limb weakness (OR = 9.11), cardioembolism as stroke mechanism (OR = 2.49) and sensory deficit (OR = 0.35) were independent variables associated with ACA stroke in comparison with PCA infarction.

Conclusion

Cardioembolism is the main cause of brain infarction in the territory of the ACA. Several clinical features are more frequent in stroke patients with ACA infarction than in patients with ischaemic stroke due to infarction in the MCA and PCA territories.     

Clinical Significance of Cerebral Microbleeds Locations in CADASIL with R544C NOTCH3 Mutation

MethodsThis is a cohort study of patients who were diagnosed with genotype-confirmed R544C-mutation CADASIL. Primary neurologic symptoms were recorded. Symptomatic strokes were defined as transient ischemic attack, ischemic strokes and hemorrhagic strokes. CMBs were defined as focal areas of round signal loss on T2*-weighted gradient echo planar images with a diameter of less than 10 mm. The locations of CMBs were divided into lobar, basal ganglia, thalamus, brain stem and cerebellum. Multiple logistic regressions were performed to identify the epidemiologic or vascular risk factors associated with symptomatic stroke in patients with CADASIL.ResultsAmong total of 51 subjects in this cohort, CMBs were present in 20 of 32 patients (64.5%) in the symptomatic stroke-group and in 8 of 19 patients (42.1%) in the non-stroke group (p = 0.16). CMBs were observed more frequently in the basal ganglia (p<0.001) and the cerebellum (p<0.018) in the symptomatic stoke group compared to the non-stroke group. The mean number of CMBs was significantly higher in the symptomatic stroke group (15.4±18.0 lesions per patients with CMBs) versus those without symptomatic stroke (3.3±3.0 lesions per patients with CMBs) (p = 0.003). Hypertension was an independent risk factor for symptomatic stroke in CADASIL (p = 0.014). It was independently associated with CMBs locations as basal ganglia (p = 0.016), thalamus (p = 0.010), brainstem (p = 0.044), and cerebellum (p = 0.049). However, It was not independently associated with CMBs on lobar lesion (p = 0.152).ConclusionsIn this study hypertension was an independent predictor of CMBs presence in specific brain locations, as well as symptomatic stroke in the CADASIL patients. The distribution and burden of CMBs might be a clinically useful marker for the risk of symptomatic stroke. However, further prospective studies on the relationship between CMBs distribution and symptomatic stroke are required in order to support these preliminary findings.     

Hemodynamic monitoring by intracardiac impedance measured by cardiac resynchronization defibrillators: Evaluation in a controlled clinical setting (BIO.Detect HF II study)

BackgroundIn patients with cardiac resynchronization therapy defibrillators (CRT-Ds), intracardiac impedance measured by dedicated CRT-D software may be used to monitor hemodynamic changes. We investigated the relationship of hemodynamic parameters assessed by intracardiac impedance and by echocardiography in a controlled clinical setting.MethodsThe study enrolled 68 patients (mean age, 66 ± 9 years; 74% males) at 12 investigational sites. The patients had an indication for CRT-D implantation, New York Heart Association class II/III symptoms, left ventricular ejection fraction 15%–35%, and a QRS duration ≥150 ms. Two months after a CRT-D implantation, hemodynamic changes were provoked by overdrive pacing. Intracardiac impedance was recorded at rest and at four pacing rates ranging from 10 to 40 beats/min above the resting rate. In parallel, echocardiography measurements were performed. We hypothesized that a mean intra-individual correlation coefficient (r_mean) between stroke impedance (difference between end-systolic and end-diastolic intracardiac impedance) measured by CRT-D and the aortic velocity time integral (i.e., stroke volume) determined by echocardiography would be significantly larger than 0.65.ResultsThe hypothesis was evaluated in 40 patients with complete data sets. The r_mean was 0.797, with a lower confidence interval bound of 0.709. The study hypothesis was met (p = 0.007). A stepwise reduction of stroke impedance and stroke volume was observed with increasing heart rate.ConclusionsIntracardiac impedance measured by implanted CRT-Ds correlated well with the aortic velocity time integral (stroke volume) determined by echocardiography. The impedance measurements bear potential and are readily available technically, not requiring implantation of additional material beyond standard CRT-D system.     

Residual Upper Arm Motor Function Primes Innervation of Paretic Forearm Muscles in Chronic Stroke after Brain-Machine Interface (BMI) Training

Background

Abnormal upper arm-forearm muscle synergies after stroke are poorly understood. We investigated whether upper arm function primes paralyzed forearm muscles in chronic stroke patients after Brain-Machine Interface (BMI)-based rehabilitation. Shaping upper arm-forearm muscle synergies may support individualized motor rehabilitation strategies.

Methods

Thirty-two chronic stroke patients with no active finger extensions were randomly assigned to experimental or sham groups and underwent daily BMI training followed by physiotherapy during four weeks. BMI sessions included desynchronization of ipsilesional brain activity and a robotic orthosis to move the paretic limb (experimental group, n = 16). In the sham group (n = 16) orthosis movements were random. Motor function was evaluated with electromyography (EMG) of forearm extensors, and upper arm and hand Fugl-Meyer assessment (FMA) scores. Patients performed distinct upper arm (e.g., shoulder flexion) and hand movements (finger extensions). Forearm EMG activity significantly higher during upper arm movements as compared to finger extensions was considered facilitation of forearm EMG activity. Intraclass correlation coefficient (ICC) was used to test inter-session reliability of facilitation of forearm EMG activity.

Results

Facilitation of forearm EMG activity ICC ranges from 0.52 to 0.83, indicating fair to high reliability before intervention in both limbs. Facilitation of forearm muscles is higher in the paretic as compared to the healthy limb (p<0.001). Upper arm FMA scores predict facilitation of forearm muscles after intervention in both groups (significant correlations ranged from R = 0.752, p = 0.002 to R = 0.779, p = 0.001), but only in the experimental group upper arm FMA scores predict changes in facilitation of forearm muscles after intervention (R = 0.709, p = 0.002; R = 0.827, p<0.001).

Conclusions

Residual upper arm motor function primes recruitment of paralyzed forearm muscles in chronic stroke patients and predicts changes in their recruitment after BMI training. This study suggests that changes in upper arm-forearm synergies contribute to stroke motor recovery, and provides candidacy guidelines for similar BMI-based clinical practice.