Combined functional task practice and dynamic high intensity resistance training promotes recovery of upper-extremity motor function in post-stroke hemiparesis: a case study

Alterations in intermuscular coordination underlying isokinetic exercise after a stroke and their implications on neurorehabilitation

Background

Abnormal intermuscular coordination limits the motor capability of stroke-affected upper limbs. By evaluating the intermuscular coordination in the affected limb under various biomechanical task constraints, the impact of a stroke on motor control can be analyzed and intermuscular coordination-based rehabilitation strategies can be developed. In this study, we investigated upper limb intermuscular coordination after a stroke during isokinetic movements.

Methods

Sixteen chronic stroke survivors and eight neurologically intact individuals were recruited. End-point forces and electromyographic activities of the shoulder and elbow muscles were measured while the participants performed isokinetic upper limb movements in a three-dimensional space. Intermuscular coordination of the stroke survivors and the control participants was quantified in the form of muscle synergies. Then, we compared the number, composition, and activation coefficients of muscle synergies and the end-point force between the groups. The correlation between the alteration of muscle synergies and the level of motor impairment was investigated.

Results

Four and five muscle synergies in the stroke and control groups were observed, respectively. The composition of muscle synergies was comparable between the groups, except that the three heads of the deltoid muscle were co-activated and formed one synergy in the stroke group, whereas those muscles formed two synergies in the control group. When the number of muscle synergies between the groups matched, the comparable composition of muscle synergies was observed in both groups. Alternatively, the modulation of synergy activation coefficients was altered after a stroke. The severity of motor impairments was negatively correlated with the similarity of the post-stroke synergies with respect to the mean control synergies.

Conclusions

Stroke-affected upper limbs seemed to modularize the activation of the shoulder and elbow muscles in a fairly similar way to that of neurologically intact individuals during isokinetic movements. Compared with free (i.e., unconstrained) movement, exercise under biomechanical constraints including the isokinetic constraint might promote the activation of muscle synergies independently in stroke survivors. We postulated the effect of biomechanical constraints on the intermuscular coordination and suggested a possible intermuscular coordination-based rehabilitation protocol that provides the biomechanical constraint appropriate to a trainee throughout the progress of rehabilitation.

The Effects of Upper Extremity Isokinetic Strengthening in Post-Stroke Hemiplegia: A Randomized Controlled Trial

OBJECTIVE

The aim of this study was to evaluate the efficacy of isokinetic strengthening in paretic upper extremity among patients with post-stroke hemiplegia.

METHODS

Hemiplegic patients with at least 6 months post-stroke and those with arm and hand Brunnstrom motor recovery stage ≥ 3 were included to the study. Patients were randomized into two groups. Isokinetic training group received 4 weeks (3 days/week) of isokinetic strengthening, while the control group was tailored strengthening exercises with exercise bands. Outcome measures were the isokinetic peak torque of wrist flexor and extensors, Fugl-Meyer Assessment of upper extremity, Stroke Impact Scale (SIS), Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, hand grip strength, peak isometric strength of wrist flexor and extensors. Outcome measures were evaluated before treatment, after treatment (at the end of week 4) and 4 weeks after the end of treatment (at the end of week 8). The trial was registered at ClinicalTtrials.gov (ID: NCT03834311).

RESULTS

After 4 weeks, changes in extensor peak torque at 60°/sn (p=0.007) and extensor peak isometric muscle strength (p=0.007) were higher in the isokinetic group (n=12) than those in the control group (n=12). At the end of week 8, only DASH score revealed a significantly higher improvement in the isokinetic group than that in the control group (p=0.014).

CONCLUSIONS

Isokinetic strengthening may provide motor and functional improvement in paretic upper extremity among patients with post-stroke hemiplegia.

Biodex© training post-stroke for postural stability in the upper trunk: A pilot study

Background

Stroke affects upper trunk postural stability and upper limb function in approximately 85% of stroke survivors. Upper trunk postural stability is essential for functioning of the upper limb and is a prerequisite for hand function. The rehabilitation of the upper limb and upper trunk post-stroke remains a challenge because of poor recovery of motor and sensory function.

Objectives

To determine the effect of Biodex© upper limb weight-bearing training on upper trunk postural stability in patients post-stroke.

Method

A longitudinal randomised control pilot trial with single blinding was undertaken to assess postural stability on the Biodex© at baseline and 1-month post-baseline. In addition to standard rehabilitative care, upper limb weight-bearing training on the Biodex© was added for participants in the experimental group. Descriptive data analysis and the Mann–Whitney test for group comparisons were done using STATA (p < 0.05).

Results

Fifteen participants took part, seven in the control and eight in the experimental group, with an overall median age of 55 years. At baseline there were statistically significant lower scores in the experimental group on overall (p = 0.02) and anterior/posterior (p = 0.009) stability level 6 (moderately unstable base of support) in the upper trunk postural stability scores. No statistically significant improvements were noted between groups on any of the Biodex© stability levels at 1-month post-baseline testing (p > 0.05).

Conclusion

Upper limb weight-bearing training with the addition of Biodex© training did not result in improvements in upper trunk postural stability.

Clinical implications

The findings suggest that exercising on a moderately unstable base of support may improve upper trunk postural stability in patients post-stroke. The addition of Biodex© training to standard rehabilitative care for retraining and exercising upper trunk postural control in a weight-bearing position does not lead to better outcomes than standard care.

Performance-Based Hybrid Control of a Cable-Driven Upper-Limb Rehabilitation Robot

Patients after stroke may have different rehabilitation needs due to various levels of disability. To satisfy such needs, a performance-based hybrid control is proposed for a cable-driven upper-limb rehabilitation robot (CDULRR). The controller includes three working modes, i.e., resistance mode, assistance mode and restriction mode, which are switched by the tracking error since it is a common index to represent motor performance. In resistance mode, the proper damping force would be provided for subjects, which is in the opposite direction to the actual velocity. In assistance mode, a method of adjusting stiffness coefficient by fuzzy logic is adopted to provide suitable assistance to help subjects. In restriction mode, the damping force is applied again to limit the movement and ensure the safety. To verify the effectiveness of the controller, the task-oriented experiments with different disturbance were conducted by ten healthy subjects. The experiments results demonstrated that the controller can adjust working modes by the subjects' motor performance. It was found that, as the increasing disturbance led to a decrease in the motor performance, the robot provided more assistance in the trainings. Adaptive adjustment of damping force and stiffness coefficient allowed the controller to induce more active effort.

Electrical Stimulation of the Motor Cortex or Paretic Muscles Improves Strength Production in Stroke Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

Transcranial direct current stimulation (tDCS) and functional electrical stimulation (FES) are two widely applied methods of electrical stimulation for motor recovery among stroke patients. This systematic review and meta-analysis investigated the efficacy of tDCS and FES for strength production in stroke patients. TYPE: Systematic review.

LITERATURE SURVEY

Studies that explored the effects of tDCS or FES on the strength production of paralyzed muscles in stroke patients were retrieved on a comprehensive set of three databases: (1) Google Scholar, (2) PubMed, and (3) the Cochrane Database of Systematic Reviews until July 2019.

METHODOLOGY

Systematic study retrieval led to the inclusion of 15 studies that reported on strength production effects after tDCS and FES interventions among stoke patients. A sham control group and randomization were used in each study. The 15 studies included 20 comparisons with sham controls, 7 of which involved tDCS and 13 of which involved FES.

SYNTHESIS

Random-effects models showed that strength production was improved after tDCS (effect size [ES] = 0.52, 95% confidence interval [CI] = 0.35-0.69, P < .001, Z = 6.05) and FES (ES = 0.47, 95% CI = 0.16-0.78, P < .003, Z = 2.99). Additionally, tDCS was shown to improve strength production in the acute (ES = 0.52, 95% CI = 0.24-0.80, P < .001, Z = 3.65), subacute (ES = 0.85, 95% CI = 0.37-1.32, P < .001, Z = 3.51), but not chronic (ES = 0.06, 95% CI = -0.47-0.60, P = .82, Z = 0.23) phases of stroke recovery. Out of the 13 studies involving FES, 12 investigated strength production in the chronic phase and one investigated in the acute phase, showing a positive effect in these two stages.

CONCLUSIONS

The results of the meta-analysis showed that tDCS and FES successfully improved strength production in stroke patients.

Efficacy of throwing exercise with TheraBand in male volleyball players with shoulder internal rotation deficit: a randomized controlled trial

Background

The Glenohumeral internal-rotation deficit (GIRD) is related to the altered eccentric external-rotator (ER), the concentric internal-rotator (IR), muscle strength, and the ER: IR ratio. GIRD has been documented as a risk factor for shoulder injuries. However, few studies have investigated the effect of an exercise training on these parameters in athletes with GIRD. Therefore, the purpose of this study was to evaluate the effects of an 8-week throwing exercise with a TheraBand for retraining the rotator cuff on Electromyography (EMG) activity of selected muscles, rotator cuff muscle strength, the glenohumeral (GH) joint IR range of motion (ROM) and GH joint position sense in asymptomatic male volleyball players with GIRD.

Methods

Sixty male volleyball players with GIRD were randomized into either a training group or a control group. The experimental group underwent an 8-week throwing exercise with a TheraBand including 5 sessions of stretching and 3 sessions of strengthening exercises per week. The control group received an active self-exercise program. EMG (onset time and muscle activation), shoulder range of motion (ROMs), strength and GH joint position sense were all assessed pre and post trainings.

Results

There were statistically significant within-group differences in the EMG activity of the anterior deltoid (p = 0.005), middle deltoid (p = 0.007), posterior deltoid (p = 0.004), infraspinatus (p = 0.001) and supraspinatus (p = 0.001) muscles, IR ROM (p = 0.001), rotator cuff muscle strength ratio (p = 0.001), and GH joint position sense (p = 0.033) in the experimental group. A 2 × 2 analysis of variance with a mixed model design and independent and paired t-tests were used for statistical analysis.

Conclusions

Throwing exercise with a TheraBand improved shoulder muscle activation, IR ROM, rotator cuff muscle strength ratio and GH joint position sense in participants with GIRD. These findings may improve the treatment of GIRD in a clinical setting. Although the results are significant, further studies should follow up the long-term effects of the Throwing exercise with a TheraBand on GIRD.

Trial registration

Current Controlled Trials using the UMIN-RCT website with ID number of, UMIN000038416 “Retrospectively registered” at 2019/10/29.

Adaptive Neural Sliding-Mode Controller for Alternative Control Strategies in Lower Limb Rehabilitation

Research on control strategies for rehabilitation robots has gradually shifted from providing therapies with fixed, relatively stiff assistance to compelling alternatives with assistance or challenge strategies to maximize subject participation. These alternative control strategies can promote neural plasticity and, in turn, increase the potential for recovery of motor coordination. In this paper, we propose a control strategy that dynamically switches between assistance and challenge modes based on the user's performance by amplifying or reducing the deviation between the user and the rehabilitation robot. For a seamless cognitive and physical interaction between the robot and the patient, we propose a multisensor fusion system to provide accurate activity and motor capability recognition, fall detection and physical fitness assessment in the rehabilitation training process. Moreover, an adaptive radial basis function (RBF) neural sliding-mode (ARNNSM) controller that dominates a mobile chaperonage lower limb rehabilitation training robot is proposed. The controller employs asynchronous deviation and functional assessment to determine the subject's capabilities and computes a corresponding assistance torque with a challenging factor for the desired locomotive function. Some sufficient conditions are derived based on algebraic graph theory and Lyapunov theory to ensure the asymptotic stability of the systems. Simulation examples illustrate the effectiveness of the proposed controllers. The ARNNSM controller and accompanying algorithm are demonstrated experimentally with healthy subjects in a new type of mobile chaperonage lower limb rehabilitation robot.

The Past, Present, and Future of Neurorehabilitation: From NUSTEP Through IV STEP and Beyond

PURPOSES

To present the history and aims of the STEP conferences; describe the interdependence of prevention, prediction, plasticity, and participation; reflect on where we stand today regarding those 4 Ps; and discuss how future neurorehabilitation should look for individuals with movement disorders.

KEY POINTS

Physical therapists have focused primarily on tertiary prevention, emphasizing primary/secondary prevention far less. Predicting optimal response to intervention is essential for primary prevention. Research examining neurorehabilitation effects mediated by brain plasticity is evolving from an emphasis on impairment outcomes toward examination of participation outcomes. CLINICAL PRACTICE RECOMMENDATIONS:: (1) Capitalize on primary and secondary prevention. (2) Administer simple, environmentally relevant predictive measures. (3) Partner with researchers to examine exercise-induced brain plasticity effects via neuroimaging. (4) Encourage physical activity to promote secondary prevention of lifestyle-related diseases and enhance participation. (5) Integrate psychological/social sciences with physiological sciences to move forward with advances in mindful health and patient-centered practices.

Position and torque control via rehabilitation robot and functional electrical stimulation

Two common rehabilitation therapies for individuals possessing neurological conditions are functional electrical stimulation (FES) and robotic assistance. This paper focuses on combining the two rehabilitation strategies for use on the biceps brachii muscle group. FES is used to elicit muscle contractions to actuate the forearm and a rehabilitation robot is used to challenge the muscle group in its efforts. Two controllers were developed and implemented to accomplish the multifaceted objective, both of which achieve global exponential stability for position and torque tracking as proven through a Lyapunov stability analysis. Experiments performed on one able bodied individual demonstrate an average RMS error of 5.8 degrees for position tracking and 0.40 Newton-meters for torque tracking.

Neurophysiological Assessment of the Electrostimulation Procedures Used in Stroke Patients during Rehabilitation

The aim of this study was to evaluate the effectiveness of the associated electrotherapeutical and kinesiotherapeutical treatment in patients after ischemic stroke (N=24), mainly by means of neurophysiological tests. All patients underwent the same 20 days of neurorehabilitation procedures. Particular attention was paid to three-stage modified electrotherapy procedures such as: oververtebral functional electrical stimulation (FES), transcutaneous electrical nerve stimulation (TENS) and the alternate neuromuscular functional electrical stimulation (NMFES) of antagonistic muscles of the wrist and the ankle (N=16). Electrotherapy was supplemented with kinesiotherapeutic (mainly PNF) procedures acting as an amplifier. Clinical assessment included muscle tension (Ashworth's scale), muscle force (Lovett's scale) and reflex scoring at wrist and ankle. However, the effectiveness of the procedures was measured by the assessment of results in complex and repetitive, bilaterally performed global electromyography (EMG) and electroneurography (ENG; M-wave studies). The statistical analysis obtained from results in clinical and neurophysiological examinations suggested that the dorsiflexion of wrist and ankle was improved in the majority of patients who took part in this study. EMG and ENG examinations showed that 20 days of therapy improved both activity in muscle motor units on the more paralyzed side (mainly within upper extremities) and to a lesser degree in the transmission of efferent impulses within motor fibers of nerves. The results obtained suggest that patients after ischemic strokes never show an isolated unilateral disability in motor functions.

No definite similarities between the results of clinical and neurophysiological studies were found, which may suggest greater accuracy of the neurophysiological evaluation.

The Past, Present, and Future of Neurorehabilitation: From NUSTEP Through IV STEP and Beyond

PURPOSES

To present the history and aims of the STEP conferences; describe the interdependence of prevention, prediction, plasticity, and participation; reflect on where we stand today regarding those 4 Ps; and discuss how future neurorehabilitation should look for individuals with movement disorders.

KEY POINTS

Physical therapists have focused primarily on tertiary prevention, emphasizing primary/secondary prevention far less. Predicting optimal response to intervention is essential for primary prevention. Research examining neurorehabilitation effects mediated by brain plasticity is evolving from an emphasis on impairment outcomes toward examination of participation outcomes. CLINICAL PRACTICE RECOMMENDATIONS:: (1) Capitalize on primary and secondary prevention. (2) Administer simple, environmentally relevant predictive measures. (3) Partner with researchers to examine exercise-induced brain plasticity effects via neuroimaging. (4) Encourage physical activity to promote secondary prevention of lifestyle-related diseases and enhance participation. (5) Integrate psychological/social sciences with physiological sciences to move forward with advances in mindful health and patient-centered practices.

Effects of functional and analytical strength training on upper-extremity activity after stroke: a randomized controlled trial

Objective

To investigate the effects of functional strengthening (using functional movements) and analytical strengthening (using repetitive movements) on level of activity and muscular strength gain in patients with chronic hemiparesis after stroke.

Method

A randomized, assessor-blinded trial was conducted in a therapist-supervised home rehabilitation program. Twenty-seven patients with chronic stroke were randomly allocated one of two groups: functional strengthening (FS) (n=13) and analytical strengthening (AS) (n=14). Each group received a five-week muscle strengthening protocol (30 minutes per day, three times per week) including functional movements or analytical movements, respectively. Pre-, post-, and ten-month follow-up outcomes included the Upper-Extremity Performance Test (primary outcome), Shoulder and Grip Strength, Active Shoulder Range of Motion (ROM), the Fugl-Meyer Assessment, and the Modified Ashworth Scale (MAS) (secondary outcomes).

Results

There was significant improvement in the Upper-Extremity Performance Test for the combined unilateral and bilateral task scores in the FS Group (mean difference 2.4; 95% CI=0.14 to 4.6) in the 10-month follow-up. No significant difference was observed between groups in the other outcomes (p>0.05).

Conclusion

A five-week home-based functional muscle strengthening induced positive results for the upper-extremity level of activity of patients with moderate impairment after chronic stroke.

To compare the effectiveness of constraint induced movement therapy versus motor relearning programme to improve motor function of hemiplegic upper extremity after stroke

Objective:

To compare the effectiveness of constraint induced movement therapy versus motor relearning programme to improve motor function of hemiplegic upper extremity after stroke.

Method:

A sample of 42 patients was recruited from the Physiotherapy Department of IPM&R and Neurology OPD of Civil Hospital Karachi through non probability purposive sampling technique. Twenty one patients were placed to each experimental and control groups. Experimental group was treated with Constraint Induced Movement Therapy (CIMT) and control group was treated with motor relearning programme (MRP) for three consecutive weeks. Pre and post treatment measurements were determined by upper arm section of Motor Assessment Scale (MAS) and Self Care item of Functional Independence Measure (FIM) Scale.

Results:

Intra group analysis showed statistically significant results (p-value<0.05) in all items of MAS in both groups. However, advanced hand activities item of MAS in MRP group showed insignificant result (p-value=0.059). Self-care items of FIM Scale also showed significant result (p-value< 0.05) in both groups except dressing upper body item (p-value=0.059) in CIMT group and grooming and dressing upper body items (p-value=0.059 & 0.063) in MRP group showed insignificant p-values.

Conclusion:

CIMT group showed more significant improvement in motor function and self-care performance of hemiplegic upper extremity as compared to MRP group in patients with sub-acute stroke assessed by the MAS and FIM scales. Thus CIMT is proved to be more statistically significant and clinically effective intervention in comparison to motor relearning programme among the patients aged between 35-60 years. Further studies are needed to evaluate CIMT effects in acute and chronic post stroke population.

Force control in chronic stroke

Force control deficits are common dysfunctions after a stroke. This review concentrates on various force control variables associated with motor impairments and suggests new approaches to quantifying force control production and modulation. Moreover, related neurophysiological mechanisms were addressed to determine variables that affect force control capabilities. Typically, post stroke force control impairments include: (a) decreased force magnitude and asymmetrical forces between hands, (b) higher task error, (c) greater force variability, (d) increased force regularity, and (e) greater time-lag between muscular forces. Recent advances in force control analyses post stroke indicated less bimanual motor synergies and impaired low-force frequency structure. Brain imaging studies demonstrate possible neurophysiological mechanisms underlying force control impairments: (a) decreased activation in motor areas of the ipsilesional hemisphere, (b) increased activation in secondary motor areas between hemispheres, (c) cerebellum involvement, and (d) relatively greater interhemispheric inhibition from the contralesional hemisphere. Consistent with identifying neurophysiological mechanisms, analyzing bimanual motor synergies as well as low-force frequency structure will advance our understanding of post stroke force control.

Kinetic measurements of hand motor impairments after mild to moderate stroke using grip control tasks

BACKGROUND

The aim of this study is to investigate quantitative outcome measurements of hand motor performance for subjects after mild to moderate stroke using grip control tasks and characterize abnormal flexion synergy of upper extremities after stroke.

METHODS

A customized dynamometer with force sensors was used to measure grip force and calculate rotation torque during the sub-maximal grip control tasks. The paretic and nonpartic sides of eleven subjects after stroke and the dominant sides of ten healthy persons were tested. Their maximal voluntary grip force was measured and used to set sub-maximal grip control tasks at three different target force levels. Force control ability was characterized by the maximal grip force, mean force percentage, coefficient of variation (CV), target deviation ratio (TDR), and rotation torque ratio (RTR). The motor impairments of subjects after stroke were also evaluated using the Fugl-Meyer assessment for upper extremity (FMA-UE) and Wolf Motor Function Test (WMFT).

RESULTS

Maximal grip force of the paretic side was significantly reduced as compared to the nonparetic side and the healthy group, while the difference of maximal grip force between the nonparetic side and the healthy group was not significant. TDR and RTR increased for all three groups with increasing target force level. There were significant differences of CV, TDR and RTR between the paretic side and the healthy group at all the force levels. CV, TDR and RTR showed significant negative correlations with FMA-UE and WMFT at 50% of maximum grip force.

CONCLUSIONS

This study designed a customized dynamometer together with an innovative measurement, RTR, to investigate the hand motor performance of subjects after mild to moderate stroke during force control tasks. And stroke-induced abnormal flexion synergy of wrist and finger muscles could be characterized by RTR. This study also identified a set of kinetic parameters which can be applied to quantitatively assess the hand motor function of subjects after mild to moderate stroke.

Introduction to Special Issue: A Review of the International Classification of Functioning, Disability and Health and Physical Therapy over the Years

BACKGROUND AND PURPOSE

The International Classification of Functioning, Disability and Health (ICF) of the World Health Organization was developed as a common framework to understand health and to describe the impact of health condition on functioning. The purpose of this paper is to summarize the literature on the use of the ICF in physical therapy practice and research.

METHODS

We performed a scoping-narrative review and searched for relevant English language articles from 2001 to 2012 in multiple databases that included MEDLINE, PsycINFO, PubMed and Physiotherapy Evidence Database. Our keywords for the search consisted of ['physical therapy' OR 'physiotherapy'] AND ['ICF']. All types of articles were considered.

RESULTS

We found 268 articles; out of which, 79 were reviewed. The years with most publications were 2011 (n = 16), 2008 (n = 15) and 2010 and 2012 (both with n = 13). Publications mostly came from the United States with 27% of the articles. The journal Physical Therapy leads with almost a third of ICF-related physical therapy publications. The ICF has been mostly used in studies of musculoskeletal and neuromuscular conditions. We found a wide array of application of the ICF in research, clinical practice and teaching (classroom and clinical education). Emerging topics included using the ICF in resource allocation and prevention and wellness.

CONCLUSION

The use of the ICF in physical therapy practice and research is promising and continues to evolve. With recent developments in ICF-based measurement and integration in assessment tools for use in the clinics, research and teaching, the need to show the added value of using the ICF in practice and research remains.

Upper extremity muscle volumes and functional strength after resistance training in older adults

Aging leads to a decline in strength and an associated loss of independence. The authors examined changes in muscle volume, maximum isometric joint moment, functional strength, and 1-repetition maximum (1RM) after resistance training (RT) in the upper extremity of older adults. They evaluated isometric joint moment and muscle volume as predictors of functional strength. Sixteen healthy older adults (average age 75 ± 4.3 yr) were randomized to a 6-wk upper extremity RT program or control group. The RT group increased 1RM significantly (p < .01 for all exercises). Compared with controls, randomization to RT led to greater functional pulling strength (p = .003), isometric shoulder-adduction moment (p = .041), elbow-flexor volume (p = .017), and shoulder-adductor volume (p = .009). Shoulder-muscle volumes and isometric moments were good predictors of functional strength. The authors conclude that shoulder strength is an important factor for performing functional reaching and pulling tasks and a key target for upper extremity RT interventions.

A task description model for robotic rehabilitation

The desire to produce robots to aid in physical neurorehabilitation has led to the control paradigm Assistance-As-Needed. This paradigm aims to assist patients in performing physical rehabilitation tasks whilst providing the least amount of assistance required, maximizing the patient's effort which is essential for recovery. Ideally the provided assistance equals the gap between the capability required to perform the task and the patient's available capability. Current implementations derive a measure of this gap by critiquing task performance based on some criteria. This paper presents a task description model for tasks performed by a patient's limb, allowing physical requirements to be calculated. Applied to two upper limb tasks typical of rehabilitation and daily activities, the effect of task variations on the task's physical requirements are observed. It is proposed that using the task description model to compensate for changing task requirements will allow better support by providing assistance closer to the true needs of the patient.

Concurrent neuromechanical and functional gains following upper-extremity power training post-stroke

BACKGROUND

Repetitive task practice is argued to drive neural plasticity following stroke. However, current evidence reveals that hemiparetic weakness impairs the capacity to perform, and practice, movements appropriately. Here we investigated how power training (i.e., high-intensity, dynamic resistance training) affects recovery of upper-extremity motor function post-stroke. We hypothesized that power training, as a component of upper-extremity rehabilitation, would promote greater functional gains than functional task practice without deleterious consequences.

METHOD

Nineteen chronic hemiparetic individuals were studied using a crossover design. All participants received both functional task practice (FTP) and HYBRID (combined FTP and power training) in random order. Blinded evaluations performed at baseline, following each intervention block and 6-months post-intervention included: Wolf Motor Function Test (WMFT-FAS, Primary Outcome), upper-extremity Fugl-Meyer Motor Assessment, Ashworth Scale, and Functional Independence Measure. Neuromechanical function was evaluated using isometric and dynamic joint torques and concurrent agonist EMG. Biceps stretch reflex responses were evaluated using passive elbow stretches ranging from 60 to 180º/s and determining: EMG onset position threshold, burst duration, burst intensity and passive torque at each speed.

RESULTS

PRIMARY OUTCOME

Improvements in WMFT-FAS were significantly greater following HYBRID vs. FTP (p = .049), regardless of treatment order. These functional improvements were retained 6-months post-intervention (p = .03).

SECONDARY OUTCOMES

A greater proportion of participants achieved minimally important differences (MID) following HYBRID vs. FTP (p = .03). MIDs were retained 6-months post-intervention. Ashworth scores were unchanged (p > .05). Increased maximal isometric joint torque, agonist EMG and peak power were significantly greater following HYBRID vs. FTP (p < .05) and effects were retained 6-months post-intervention (p's < .05). EMG position threshold and burst duration were significantly reduced at fast speeds (≥120º/s) (p's < 0.05) and passive torque was reduced post-washout (p < .05) following HYBRID.

CONCLUSIONS

Functional and neuromechanical gains were greater following HYBRID vs. FPT. Improved stretch reflex modulation and increased neuromuscular activation indicate potent neural adaptations. Importantly, no deleterious consequences, including exacerbation of spasticity or musculoskeletal complaints, were associated with HYBRID. These results contribute to an evolving body of contemporary evidence regarding the efficacy of high-intensity training in neurorehabilitation and the physiological mechanisms that mediate neural recovery.

Eccentric Versus Concentric Resistance Training to Enhance Neuromuscular Activation and Walking Speed Following Stroke

Background. Impaired voluntary neuromuscular activation of agonist muscles is a primary determinant of weakness and motor dysfunction following stroke. Objective. To determine whether eccentric resistance training (ECC) resistance training is superior to concentric resistance training (CON) resistance training to enhance neuromuscular activation, strength, and walking speed after stroke. Methods. A total of 34 adults poststroke participated in a staged intervention comprising (1) either CON-only or ECC-only resistance training of the paretic leg followed by (2) gait training. Changes in voluntary neuromuscular activation and power were assessed for both the trained paretic and untrained nonparetic legs. Self-selected and fast walking speeds were also assessed. Results. In response to resistance training, the ECC group experienced larger improvements in neuromuscular activation of paretic leg muscles, rectus femoris and vastus medialis ( P < .005), and the largest gains in paretic leg power (+74% for ECC contractions, P < .0001). ECC also had greater cross-education of increased power to the untrained nonparetic leg (12%-14%, P = .006). Over the course of gait training, much of the gain in paretic leg activation in the ECC group was lost, such that the net change in agonist activation was comparable between the CON and ECC groups when the full intervention was completed. Nevertheless, improvement in walking speed postintervention was more prevalent in the ECC than CON group. Conclusion. ECC resistance training was more effective for improving bilateral neuromuscular activation, strength, and walking speed following stroke. Future research should assess whether a longer duration ECC training program can provide further benefit.

Isokinetic muscle strengthening after acquired cerebral damage: a literature review

OBJECTIVE

Isokinetic strengthening is a rehabilitation technique rarely used in stroke patients. However, the potential benefits of force and endurance training in this population are strongly suspected.

METHOD

This literature review synthesizes the results of clinical trials on this topic. The research was conducted on PubMed, using "Stroke", "rehabilitation", "isokinetic", "upper limb" and "training" as keywords.

RESULTS

Seventeen studies focusing on the use of isokinetics in assessment or rehabilitation (six studies) following stroke were reviewed. For the lower limb, muscle strength and walking ability improved after isokinetic rehabilitation programs. For the upper limb, the only two studies found in the literature suggest improvement in the strength of the trained muscles, of grip force, of the Fugl-Meyer motor score and of global functional capacities. This review does not reveal any consensus on the protocols to be implemented: type of muscle contraction, velocities….

CONCLUSION

While isokinetic strengthening has not proven its efficiency in rehabilitation of the upper limb following stroke, its interest with regard to rehabilitation of the lower limbs has been recognized. Randomized controlled trials in this field are necessary to confirm its efficiency, especially concerning upper arm rehabilitation.

Differential Effects of Power Training Versus Functional Task Practice on Compensation and Restoration of Arm Function After Stroke

Background. Improved upper-extremity (UE) movement with stroke rehabilitation may involve restoration of more normal or development of compensatory movement patterns. Objective. The authors investigated the differential effects of functional task practice (FTP) and dynamic resistance training (POWER) on clinical function and reaching kinematics in an effort to distinguish between mechanisms of gains. Methods. A total of 14 hemiparetic individuals were randomly assigned to 10 weeks of either FTP or POWER and then crossed over to 10 weeks of the alternate treatment. Treatment order A was FTP followed by POWER, whereas treatment order B was POWER followed by FTP. Evaluation before and after each treatment block included a battery of clinical evaluations and kinematics of paretic UE functional reach to grasp. Results. Both FTP and POWER improved movement accuracy, as revealed by a shift toward normal, including fewer submovements and reduced reach-path ratio. However, active range of motion revealed differential treatment effects. Shoulder flexion and elbow extension decreased with FTP and were associated with increased trunk displacement. In contrast, shoulder flexion and elbow extension excursion increased with POWER and were associated with significantly reduced trunk displacement. Treatment order B (POWER followed by FTP) revealed greater overall improvements. Conclusion. FTP increases compensatory movement patterns to improve UE function. POWER leads to more normal movement patterns. POWER prior to FTP may enhance the benefits of repetitive task practice.

Exploring expectations for upper-extremity motor treatment in people after stroke: a secondary analysis

OBJECTIVE

We explored expectations for outcomes during a research intervention for people with stroke.

METHOD

Twelve people with chronic stroke participated in this secondary analysis from a pilot trial of a high-repetition, task-specific, upper-extremity intervention. First, we examined relationships between individual expectancy and session-by-session achievement of high numbers of repetitions. Second, we examined the relationship between expectancy for the intervention as a whole and improvements in upper-extremity motor function. We used Spearman rank-order correlation coefficients to evaluate the relationships.

RESULTS

Correlations between individual expectancy and session-by-session achievement ranged from 0 to .84. Expectancy for improvement from the intervention was good (average = 7 of 10) but had a low correlation (.17) with actual improvement.

CONCLUSION

Individual expectancy ratings were inconsistently related to session-by-session achievement. Expectancy for the invention as a whole was not related to improvement in upper-extremity motor function.

Systematic literature review on ICF from 2001 to 2009: its use, implementation and operationalisation

PURPOSE

To present a systematic literature review on the state of the art of the utilisation of the International Classification of Functioning, Disability and Health (ICF) since its release in 2001.

METHOD

The search was conducted through EMBASE, MEDLINE and PsychInfo covering the period between 2001 and December 2009. Papers were included if ICF was mentioned in title or abstract. Papers focussing on the ICF-CY and clinical research on children and youth only were excluded. Papers were assigned to six different groups covering the wide scenario of ICF application.

RESULTS

A total of 672 papers, coming from 34 countries and 211 different journals, were included in the analysis. The majority of publications (30.8%) were conceptual papers or papers reporting clinical and rehabilitation studies (25.9%). One-third of the papers were published in 2008 and 2009.

CONCLUSIONS

The ICF contributed to the development of research on functioning and on disability in clinical, rehabilitation as well as in several other contexts, such as disability eligibility and employment. Diffusion of ICF research and use in a great variety of fields and scientific journals is a proof that a cultural change and a new conceptualisation of functioning and disability is happening.

Translating animal doses of task-specific training to people with chronic stroke in 1-hour therapy sessions: a proof-of-concept study

OBJECTIVE

The purposes of this study were to (1) examine the feasibility of translating high-repetition doses of upper-extremity (UE) task-specific training to people with stroke within the confines of the current outpatient delivery system of 1-hour therapy sessions and (2) to gather preliminary data regarding the potential benefit of this intensity of training.

METHODS

A total of 15 patients with chronic (>6 months) UE paresis caused by stroke underwent 3 weeks of baseline assessments followed by 6 weeks of the high-repetition intervention (3 sessions/wk for 6 weeks). During each 1-hour session, participants were challenged to complete 300 or more repetitions of UE functional task training (3 tasks x 100 repetitions). Assessments during and after the intervention were used to measure feasibility and potential benefit.

RESULTS

For the 13 participants completing the intervention, the average number of repetitions per session was 322. The percentage of sessions attended was 97%. Participant ratings of pain and fatigue were low. Action Research Arm test scores improved an average of 8 points during the intervention and were maintained at the 1-month follow-up. Secondary measures of activity and participation increased, but the measure of impairment did not.

CONCLUSIONS

It is feasible to deliver hundreds of repetitions of task-specific training to people with stroke in 1-hour therapy sessions. Preliminary outcome data suggest that this intervention may be beneficial for some people with stroke.

Physical fitness training for stroke patients

BACKGROUND

Physical fitness is low after stroke. It is unknown whether improving physical fitness after stroke reduces disability.

OBJECTIVES

To determine whether fitness training (cardiorespiratory or strength, or both) after stroke reduces death, dependence and disability. The secondary aims were to determine the effects of fitness training on physical fitness, mobility, physical function, health status and quality of life, mood and incidence of adverse events.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched March 2009), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2007), MEDLINE (1966 to March 2007), EMBASE (1980 to March 2007), CINAHL (1982 to March 2007), and six additional databases to March 2007. We handsearched relevant journals and conference proceedings, and screened bibliographies. We searched trials registers and contacted experts in the field.

SELECTION CRITERIA

We included randomised controlled trials if the aim of the intervention was to improve muscle strength or cardiorespiratory fitness, or both, and if the control groups comprised either no intervention, usual care or a non-exercise intervention.

DATA COLLECTION AND ANALYSIS

Two review authors determined trial eligibility and quality. One review author extracted outcome data at end of intervention and follow-up scores, or as change from baseline scores. Diverse outcome measures limited the intended analysis.

MAIN RESULTS

We included 24 trials, involving 1147 participants, comprising cardiorespiratory (11 trials, 692 participants), strength (four trials, 158 participants) and mixed training interventions (nine trials, 360 participants). Death was infrequent at the end of the intervention (1/1147) and follow up (8/627). No dependence data were reported. Diverse disability measures made meta-analysis difficult; the majority of effect sizes were not significant. Cardiorespiratory training involving walking, improved maximum walking speed (mean difference (MD) 6.47 metres per minute, 95% confidence interval (CI) 2.37 to 10.57), walking endurance (MD 38.9 metres per six minutes, 95% CI 14.3 to 63.5), and reduced dependence during walking (Functional Ambulation Categories MD 0.72, 95% CI 0.46 to 0.98). Current data include few strength training trials, and lack non-exercise attention controls, long-term training and follow up.

AUTHORS' CONCLUSIONS

The effects of training on death, dependence and disability after stroke are unclear. There is sufficient evidence to incorporate cardiorespiratory training, involving walking, within post-stroke rehabilitation in order to improve speed, tolerance and independence during walking. Further trials are needed to determine the optimal exercise prescription after stroke and identify any long-term benefits.

Dampace: Design of an Exoskeleton for Force-Coordination Training in Upper-Extremity Rehabilitation

The Dampace exoskeleton combines functional exercises resembling activities of daily living with impairment-targeted force-coordination training. The goal of this paper is to evaluate the performance of the Dampace. In the design, the joint rotations are decoupled from the joint translations; the robot axes align themselves to the anatomical axes, overcoming some of the traditional difficulties of exoskeletons. Setup times are reduced to mere minutes and static reaction forces are kept to a minimum. The Dampace uses hydraulic disk brakes, which can resist rotations with up to 50 N m and have a torque bandwidth of 10 Hz for multisine torques of 20 N m. The brakes provide passive control over the movement; the patients’ movements can be selectively resisted, but active movement assistance is impossible and virtual environments are restricted. However, passive actuators are inherently safe and force active patient participation. In conclusion, the Dampace is well suited to offer force-coordination training with functional exercises.

Elastic, viscous, and mass load effects on poststroke muscle recruitment and co-contraction during reaching: a pilot study

BACKGROUND

Resistive exercise after stroke can improve strength (force-generating capacity) without increasing spasticity (velocity-dependent hypertonicity). However, the effect of resistive load type on muscle activation and co-contraction after stroke is not clear.

OBJECTIVE

The purpose of this study was to determine the effect of load type (elastic, viscous, or mass) on muscle activation and co-contraction during resisted forward reaching in the paretic and nonparetic arms after stroke.

DESIGN

This investigation was a single-session, mixed repeated-measures pilot study.

METHODS

Twenty participants (10 with hemiplegia and 10 without neurologic involvement) reached forward with each arm against equivalent elastic, viscous, and mass loads. Normalized shoulder and elbow electromyography impulses were analyzed to determine agonist muscle recruitment and agonist-antagonist muscle co-contraction.

RESULTS

Muscle activation and co-contraction levels were significantly higher on virtually all outcome measures for the paretic and nonparetic arms of the participants with stroke than for the matched control participants. Only the nonparetic shoulder responded to load type with similar activation levels but variable co-contraction responses relative to those of the control shoulder. Elastic and viscous loads were associated with strong activation; mass and viscous loads were associated with minimal co-contraction.

LIMITATIONS

A reasonable, but limited, range of loads was available.

CONCLUSIONS

Motor control deficits were evident in both the paretic and the nonparetic arms after stroke when forward reaching was resisted with viscous, elastic, or mass loads. The paretic arm responded with higher muscle activation and co-contraction levels across all load conditions than the matched control arm. Smaller increases in muscle activation and co-contraction levels that varied with load type were observed in the nonparetic arm. On the basis of the response of the nonparetic arm, this study provides preliminary evidence suggesting that viscous loads elicited strong muscle activation with minimal co-contraction. Further intervention studies are needed to determine whether viscous loads are preferable for poststroke resistive exercise programs.

Review of control strategies for robotic movement training after neurologic injury

There is increasing interest in using robotic devices to assist in movement training following neurologic injuries such as stroke and spinal cord injury. This paper reviews control strategies for robotic therapy devices. Several categories of strategies have been proposed, including, assistive, challenge-based, haptic simulation, and coaching. The greatest amount of work has been done on developing assistive strategies, and thus the majority of this review summarizes techniques for implementing assistive strategies, including impedance-, counterbalance-, and EMG- based controllers, as well as adaptive controllers that modify control parameters based on ongoing participant performance. Clinical evidence regarding the relative effectiveness of different types of robotic therapy controllers is limited, but there is initial evidence that some control strategies are more effective than others. It is also now apparent there may be mechanisms by which some robotic control approaches might actually decrease the recovery possible with comparable, non-robotic forms of training. In future research, there is a need for head-to-head comparison of control algorithms in randomized, controlled clinical trials, and for improved models of human motor recovery to provide a more rational framework for designing robotic therapy control strategies.

Progressive shoulder abduction loading is a crucial element of arm rehabilitation in chronic stroke

BACKGROUND

Total reaching range of motion (work area) diminishes as a function of shoulder abduction loading in the paretic arm in individuals with chronic hemiparetic stroke. This occurs when reaching outward against gravity or during transport of an object.

OBJECTIVES

This study implements 2 closely related impairment-based interventions to identify the effect of a subcomponent of reaching exercise thought to be a crucial element in arm rehabilitation.

METHODS

A total of 14 individuals with chronic moderate to severe hemiparesis participated in the participant-blinded, randomized controlled study. The experimental group progressively trained for 8 weeks to actively support the weight of the arm, up to and beyond, while reaching to various outward targets. The control group practiced the same reaching tasks with matched frequency and duration with the weight of the arm supported. Work area and isometric strength were measured before and after the intervention.

RESULTS

Change scores for work area at 9 loads were calculated for each group. Change scores were significantly larger for the experimental group indicating a larger increase in work area, especially shoulder abduction loads equivalent to those experienced during object transport. Changes in strength were not found within or between groups.

CONCLUSIONS

Progressive shoulder abduction loading can be utilized to ameliorate reaching range of motion against gravity. Future work should investigate the dosage response of this intervention, as well as test whether shoulder abduction loading can augment other therapeutic techniques such as goal-directed functional task practice and behavioral shaping to enhance real-world arm function.

Basic motor capacity in relation to object manipulation and general manual ability in young children with spastic cerebral palsy

OBJECTIVE

Limited resources in terms of elementary functions may be a limiting factor for functional activities. The objective of the study was to examine basic hand motor capacities in young children with bilateral spastic cerebral palsy (BSCP) and to compare with deficits in functional activities.

METHOD

Eighty-eight children with BSCP, 3-6 years of age, manipulated a grip object (200g) equipped with a uniaxial force sensor. Basic motor capacity was assessed based upon (1) maximal grip strength and (2) production of fast repetitive grip force changes (FFC) while holding the object on the table. Subjects' performance on this task was compared to the grip force amplitude and force rate assessed while the subject was lifting the same object. Results were compared between different degrees of manual ability according to the Manual Ability Classification System (MACS).

RESULTS

In children with BSCP, even in high-functioning children with MACS 1, fast grip force changes and grip strength were 2 SDs and more below the mean of controls. Differences increased from MACS 2 to 4 but not between MACS 1 and 2. During lifting children with BSCP used considerable proportions of their maximum grip strength (40-90%) and of their grip force rates during 70% vs. 86%. In some children with low manual abilities (MACS 3/4), grip force rates during lifting were higher than during FFC.

CONCLUSION

In children with BSCP, basic motor capacity may influence manual ability, particularly in children with MACS 3 and 4. In some of these children, the underlying processes during lifting may also differ qualitatively.