Effects of Repetitive Peripheral Magnetic Stimulation on Upper-Limb Spasticity and Impairment in Patients With Spastic Hemiparesis: A Randomized,Double-Blind,Sham-Controlled Study

Objective

To investigate short-term and long-term effects of repetitive peripheral magnetic stimulation (rpMS) on spasticity and motor function.

Design

Monocentric, randomized, double-blind, sham-controlled trial.

Setting

Neurologic rehabilitation hospital.

Participants

Patients (N=66) with severe hemiparesis and mild to moderate spasticity resulting from a stroke or a traumatic brain injury. The average time ± SD since injury for the intervention groups was 26±71 weeks or 37±82 weeks.

Interventions

rpMS for 20 minutes or sham stimulation with subsequent occupational therapy for 20 minutes, 2 times a day, over a 2-week period.

Main Outcome Measures

Modified Tardieu Scale and Fugl-Meyer Assessment (arm score), assessed before therapy, at the end of the 2-week treatment period, and 2 weeks after study treatment. Additionally, the Tardieu Scale was assessed after the first and before the third therapy session to determine any short-term effects.

Results

Spasticity (Tardieu >0) was present in 83% of wrist flexors, 62% of elbow flexors, 44% of elbow extensors, and 10% of wrist extensors. Compared with the sham stimulation group, the rpMS group showed short-term effects on spasticity for wrist flexors (P=.048), and long-term effects for elbow extensors (P<.045). Arm motor function (rpMS group: median 5 [4–27]; sham group: median 4 [4–9]) did not significantly change over the study period in either group, whereas rpMS had a positive effect on sensory function.

Conclusions

Therapy with rpMS increases sensory function in patients with severe limb paresis. The magnetic stimulation, however, has limited effect on spasticity and no effect on motor function.     

Effects of sensorimotor trunk impairments on trunk and upper limb joint kinematics and kinetics during sitting pivot transfers in individuals with a spinal cord injury

Background

Depending on the level and severity of the sensorimotor impairment in individuals with a spinal cord injury, the subsequent reduced seated postural stability and strength generating-capacity at the upper limbs could affect performance during sitting pivot transfer. This study aimed to determine the effects of sensorimotor impairments on head, trunk and upper limb movement and efforts during sitting pivot transfers.

Methods

Twenty-six individuals with a spinal cord injury participated and were stratified in two subgroups: with (N = 15) and without voluntary motor control (N = 11) of their lower back and abdominal muscles. Kinematics and kinetics of sitting pivot transfer were collected using a transfer assessment system. Mean joint angles and movement amplitudes and peak and average joint moments were compared between subgroups using independent Student t-tests (P < 0.05) for the weight-bearing sitting pivot transfer phases.

Findings

The subgroup without voluntary control of their lower back and abdominal muscles had significantly greater forward trunk flexion compared to the other subgroup resulting in higher wrist extension and elbow flexion at both upper limbs. No significant joint moment difference was found between the subgroups.

Interpretation

Individuals with spinal cord injury who have no voluntary motor control of their abdominal and lower back muscles increase forward trunk flexion during sitting pivot transfers 1) to increase stiffness of their spine that may optimize the strength-generating ability of their thoracohumeral muscles and 2) to lower their center of mass that may facilitate lift-off and enhance the overall stability during sitting pivot transfers.     

Upper limb kinetic analysis of three sitting pivot wheelchair transfer techniques

Background

The objective of this study was to investigate differences in shoulder, elbow and hand kinetics while performing three different SPTs that varied in terms of hand and trunk positioning.

Methods

Fourteen unimpaired individuals (8 male and 6 female) performed three variations of sitting pivot transfers in a random order from a wheelchair to a level tub bench. Two transfers involved a forward flexed trunk (head–hips technique) and the third with the trunk remaining upright. The two transfers involving a head hips technique were performed with two different leading hand initial positions. Motion analysis equipment recorded upper body movements and force sensors recorded hand reaction forces. Shoulder and elbow joint and hand kinetics were computed for the lift phase of the transfer.

Findings

Transferring using either of the head hips techniques compared to the trunk upright style of transferring resulted in reduced superior forces at the shoulder (P < 0.002), elbow (P < 0.004) and hand (P < 0.013). There was a significant increase in the medial forces in the leading elbow (P = 0.049) for both head hip transfers and the trailing hand for the head hip technique with the arm further away from the body (P < 0.028). The head hip techniques resulted in higher shoulder external rotation, flexion and extension moments compared to the trunk upright technique (P < 0.021).

Interpretation

Varying the hand placement and trunk positioning during transfers changes the load distribution across all upper limb joints. The results of this study may be useful for determining a technique that helps preserve upper limb function overtime.     

Increased power generation in impaired lower extremities correlated with changes in walking speeds in sub-acute stroke patients

Background

Establishing changes in net joint power in the lower extremity of patients during recovery of walking might direct gait training in early stroke rehabilitation. It is hypothesized that (1) net joint power in the lower extremity joints would increase in sub-acute stroke patients following gait rehabilitation, and (2) the improvements in net joint power would be significantly correlated with changes in walking speed.

Methods

Thirteen sub-acute patients (<3 months from stroke onset) participated in the study. All patients completed 6 weeks of gait training (3 weeks of robotic gait training and 3 weeks of physiotherapy). The gait patterns were analyzed using 3D motion analysis before and after training. The assessed variables were; gait speed and the net peak joint power of the ankle plantar flexors, hip extensors, hip flexors, hip abductors, and knee extensors.

Findings

Ankle plantar flexor power in the impaired limb and hip extensor power in the unimpaired limb increased significantly following training (133% and 77%, respectively; P < 0.002). Improvements (from 20% to 133%) in net joint power of the ankle plantar flexors, hip extensors, hip flexors, and hip abductors of the impaired limb and ankle plantar flexors and hip abductors of the unimpaired limb significantly correlated with the recovery of walking speed following training (0.24 m/s to 0.51 m/s) (r = 0.71–0.86).

Interpretation

The findings suggested investigations for strengthening the plantar flexors, hip flexors, hip extensors, and hip abductors concentrically, and knee extensors eccentrically in the impaired limb to determine the effectiveness in improving gait performance.     

Use of a geared wheelchair wheel to reduce propulsive muscular demand during ramp ascent: Analysis of muscle activation and kinematics

Background

Shoulder muscle overuse has been linked to the high prevalence of shoulder injuries in manual wheelchair users. Ramp ascent is a barrier that is often faced by manual wheelchair users that requires higher muscle activations than level wheelchair propulsion. Additionally, reported subjective measures of shoulder pain are reduced amongst manual wheelchair users when using a wheelchair wheel outfitted with a gear mechanism. The purpose of the current investigation was to investigate shoulder muscle activation levels and upper limb kinematics during ramp ascent with and without the use of a geared wheel.

Methods

Thirteen healthy participants (6 male and 7 female) performed ramp ascent on four ramp grades (1:12, 1:10, 1:8, 1:6) using three wheel conditions (gear, no gear, standard). Electromyographic (EMG) activity of select shoulder muscles as well as kinematics of the right upper limb were collected during ramp ascent. Peak and integrated EMG as well as peak wrist, elbow, and shoulder kinematics were obtained from all ramp ascent trials.

Findings

Peak EMG of the shoulder flexors decreased by an average of 17% (P ? 0.0229) during ramp ascent with the geared wheel. Integrated EMG increased by 67% (P ? 0.0034) as a consequence of an 86% increase (P = 0.0009) in ramp ascent duration during the geared wheel condition. There were no significant differences between the non-geared and standard wheel conditions.

Interpretation

Caution must be used if using the gear ratio for prolonged periods due to potential for muscle fatigue since the overall muscle effort to move a fixed distance is higher with the gear ratio. Reducing peak demands may benefit wheelchair users with performing more strenuous tasks of daily living.     

The effect of lateral epicondylosis on upper limb mechanical parameters

Background

Lateral epicondylosis is a prevalent and costly musculoskeletal disorder characterized by degeneration of the common extensor tendon origin at the lateral epicondyle. Grip strength is commonly affected due to lateral epicondylosis. However, less is known about the effect of lateral epicondylosis on other functional parameters such as ability to react to rapid loading.

Methods

Twenty-nine lateral epicondylosis participants and ten controls participated in a case-control study comparing mechanical parameters (mass, stiffness and damping), magnetic resonance imaging signal intensity and grip strength of injured and uninjured limbs. A mixed effects model was used to assess the effect of dominance and injury on mechanical parameters and grip strength.

Findings

Significant effect of injury and dominance was observed on stiffness, damping and grip strength. An injured upper limb had, on average, 18% less stiffness (P < 0.01, 95% CI [9.8%, 26%]), 21% less damping (P < 0.01, 95% CI [11%, 31%]) and 50% less grip strength (P < 0.01, 95% CI [37%, 61%]) than an uninjured upper limb. The dominant limb had on average 15% more stiffness (P < 0.01, 95% CI [8.0%, 23%], 33% more damping (P < 0.01, 95% CI [22%, 45%]), and 24% more grip strength (P < 0.01, 95% CI [6.6%, 44%]) than the non-dominant limb.

Interpretation

Lower mechanical parameters are indicative of a lower capacity to oppose rapidly rising forces and quantify an important aspect of upper limb function. For individuals engaged in manual or repetitive activities involving the upper limb, a reduction in ability to oppose these forces may result in increased risk for injury or recurrence.     

Interlimb Coordination During the Stance Phase of Gait in Subjects With Stroke

Objective

To analyze the relation between contralesional and ipsilesional limbs in subjects with stroke during step-to-step transition of walking.

Design

Observational, transversal, analytical study with a convenience sample.

Setting

Physical medicine and rehabilitation clinic.

Participants

Subjects (n=16) with poststroke hemiparesis with the ability to walk independently and healthy controls (n=22).

Interventions

Not applicable.

Main Outcome Measures

Bilateral lower limbs electromyographic activity of the soleus (SOL), gastrocnemius medialis, tibialis anterior, biceps femoris, rectus femoris, and vastus medialis (VM) muscles and the ground reaction force were analyzed during double-support and terminal stance phases of gait.

Results

The propulsive impulse of the contralesional trailing limb was negatively correlated with the braking impulse of the leading limb during double support (r=−.639, P=.01). A moderate functional relation was observed between thigh muscles (r=−.529, P=.035), and a strong and moderate dysfunctional relation was found between the plantar flexors of the ipsilesional limb and the vastus medialis of the contralesional limb, respectively (SOL-VM, r=−.80, P<.001; gastrocnemius medialis-VM, r=−.655, P=.002). Also, a functional moderate negative correlation was found between the SOL and rectus femoris muscles of the ipsilesional limb during terminal stance and between the SOL (r=−.506, P=.046) and VM (r=−.518, P=.04) muscles of the contralesional limb during loading response, respectively. The trailing limb relative impulse contribution of the contralesional limb was lower than the ipsilesional limb of subjects with stroke (P=.02) and lower than the relative impulse contribution of the healthy limb (P=.008) during double support.

Conclusions

The findings obtained suggest that the lower performance of the contralesional limb in forward propulsion during gait is related not only to contralateral supraspinal damage but also to a dysfunctional influence of the ipsilesional limb.     

Extracorporeal Shock Waves Versus Botulinum Toxin Type A in the Treatment of Poststroke Upper Limb Spasticity: A Randomized Noninferiority Trial

Objective

To investigate whether extracorporeal shock wave therapy (ESWT) is noninferior to botulinum toxin type A (BoNT-A) for the treatment of poststroke upper limb spasticity.

Épidémiologie des pathologies du membre supérieur dominant chez les joueurs de tennis français

Objective

This retrospective study aimed at describing the epidemiology of dominant upper limb pathologies in French male and female tennis players aged between 11 and 30 years, and to study the relationships between injured/non-injured status and tennis practice.

Material and methods

One hundred and fifty six male and 67 female competitive French tennis players filled out a questionnaire to characterize their tennis practice and medical condition.

Results

Forty-one percent of players were injured at the dominant upper limb during the five years before the questionnaire. These injuries affected the musculotendinous structure (84%) at the elbow (42%), shoulder (23%) and wrist (21%) joints. Strong and significant relationships were found between injured/non-injured status and skill-level (ES = 0.33; P < 0.001), as well as between injured/non-injured status and rate of progression (ES = 0.50; P < 0.001). Tennis players practicing competition at high level and progressing rapidly could suffer from insufficient morphological adaptations of their dominant upper limb, hence suggesting that the strength and conditioning training program may focus on prophylactic objectives rather than on performance objectives at the upper limb sites.     

Simulated effect of reaction force redirection on the upper extremity mechanical demand imposed during manual wheelchair propulsion

Background

Manual wheelchair propulsion is associated with overuse injuries of the shoulder. Reaction force redirection relative to upper extremity segments was hypothesized as a means to redistribute mechanical load imposed on the upper extremity without decrements in wheelchair propulsion performance.

Methods

Two individuals performed wheelchair propulsion under simulated inclined (graded) conditions using self-selected control strategies. Upper extremity kinematics and reaction forces applied to the wheel were quantified and used as input into an experiment-based multi-link inverse dynamics model that incorporates participant-specific experimental results. Reaction force direction was systematically modified to determine the mechanical demand imposed on the upper extremity (elbow and shoulder net joint moments and net joint forces) during wheelchair propulsion. Results were presented as solution spaces to examine the upper extremity load distribution characteristics within and between participants across a range of reaction force directions.

Findings

Redirection of the reaction force relative to the upper extremity segments provides multiple solutions for redistributing mechanical demand across the elbow and shoulder without decrements in manual wheelchair propulsion performance. The distribution of load across RF directions was participant specific and was found to vary with time during the push phase.

Interpretation

Solution spaces provide a mechanical basis for individualized interventions that aim to maintain function and redistribute load away from structures at risk for injury (e.g. reduce demand imposed on shoulder flexors (reduce shoulder net joint moment) or reduce potential for impingement (reduce shoulder net joint force).     

Short-term changes in median nerve neural tension after a suboccipital muscle inhibition technique in subjects with cervical whiplash: a randomised controlled trial

Objectives

To assess the immediate effect of a suboccipital muscle inhibition (SMI) technique on: (a) neck pain, (b) elbow extension range of motion during the upper limb neurodynamic test of the median nerve (ULNT-1), and (c) grip strength in subjects with cervical whiplash; and determine the relationships between key variables.

Design

Randomised, single-blind, controlled clinical trial.

Setting

Faculty of Nursing, Physiotherapy and Podiatry, University of Seville, Spain.

Participants

Forty subjects {mean age 34 years [standard deviation (SD) 3.6]} with Grade I or II cervical whiplash and a positive response to the ULNT-1 were recruited and distributed into two study groups: intervention group (IG) (n = 20) and control group (CG) (n = 20).

Interventions

The IG underwent the SMI technique for 4 minutes and the CG received a sham (placebo) intervention. Measures were collected immediately after the intervention.

Main outcome measures

The primary outcome was elbow range of motion during the ULNT-1, measured with a goniometer. The secondary outcomes were self-perceived neck pain (visual analogue scale) and free-pain grip strength, measured with a digital dynamometer.

Results

The mean baseline elbow range of motion was 116.0° (SD 10.2) for the CG and 130.1° (SD 7.8) for the IG. The within-group comparison found a significant difference in elbow range of motion for the IG [mean difference −15.4°, 95% confidence interval (CI) −20.1 to −10.6; P = 0.01], but not for the CG (mean difference −4.9°, 95% CI −11.8 to 2.0; P = 0.15). In the between-group comparison, the difference in elbow range of motion was significant (mean difference −10.5°, 95% CI −18.6 to −2.3; P = 0.013), but the differences in grip strength (P = 0.06) and neck pain (P = 0.38) were not significant.

Conclusion

The SMI technique has an immediate positive effect on elbow extension in the ULNT-1. No immediate effects on self-perceived cervical pain or grip strength were observed.     

Upper Limb Assessment in Multiple Sclerosis: A Systematic Review of Outcome Measures and their Psychometric Properties

Objective

To provide an overview of applied upper limb outcome measures in multiple sclerosis (MS) according to the International Classification of Functioning, Disability and Health (ICF) levels and to review their psychometric properties in MS.

Data Sources

PubMed and Web of Knowledge.

Study Selection

Articles published until June 2013 were selected when written in English, published in the last 25 years, peer reviewed, including >5 persons with MS, and including standardized clinical upper limb outcome measures. Included articles were screened based on title/abstract and full text by 2 independent reviewers. In case of doubt, feedback from a third independent reviewer was obtained. Additionally, references lists were checked for relevant articles. Of the articles, 109 met the selection criteria and were included for data extraction.

Data Extraction

All reported clinical upper limb outcome measures were extracted from the included studies and classified according to the ICF levels by 2 independent reviewers. In addition, available psychometric properties (reliability, validity, responsiveness) in MS were summarized and discussed.

Data Synthesis

A diversity of outcome measures assessing impairments on the body functions and structures level (n=33), upper limb capacity (n=11), and performance (n=8) on the activity level were extracted from 109 articles. Hand grip strength and the nine-hole peg test (NHPT) were the most frequently used outcome measures. However, multiple outcome measures are necessary to encapsulate the multidimensional character of the upper limb function. The psychometric properties were insufficiently documented for most of the outcome measures, except for the NHPT.

Conclusions

The results of this review may help with the selection of appropriate outcome measures and may guide future research regarding the psychometric properties in MS.     

Gravity-Supported Exercise With Computer Gaming Improves Arm Function in Chronic Stroke

Objective

To investigate the effect of 4 to 6 weeks of exergaming with a computer mouse embedded within an arm skate on upper limb function in survivors of chronic stroke.

Design

Intervention study with a 4-week postintervention follow-up.

Setting

In home.

Participants

Survivors (N=13) of chronic (≥6mo) stroke with hemiparesis of the upper limb with stable baseline Fugl-Meyer assessment scores received the intervention. One participant withdrew, and 2 participants were not reassessed at the 4-week follow-up. No participants withdrew as a result of adverse effects.

Intervention

Four to 6 weeks of exergaming using the arm skate where participants received either 9 (n=5) or 16 (n=7) hours of game play.

Main Outcome Measure

Upper limb component of the Fugl-Meyer assessment.

Results

There was an average increase in the Fugl-Meyer upper limb assessment score from the beginning to end of the intervention of 4.9 points. At the end of the 4-week period after the intervention, the increase was 4.4 points.

Conclusions

A 4- to 6-week intervention using the arm skate significantly improved arm function in survivors of chronic stroke by an average of 4.9 Fugl-Meyer upper limb assessment points. This research shows that a larger-scale randomized trial of this device is warranted and highlights the potential value of using virtual reality technology (eg, computer games) in a rehabilitation setting.     

Mirror Therapy Enhances Motor Performance in the Paretic Upper Limb After Stroke: A Pilot Randomized Controlled Trial

Objective

To investigate the effectiveness of mirror therapy (MT) combined with bilateral arm training and graded activities to improve motor performance in the paretic upper limb after stroke.

Design

Randomized, controlled, assessor-blinded study.

Setting

Inpatient stroke rehabilitation center of a tertiary care teaching hospital.

Participants

Patients with first-time ischemic or hemorrhagic stroke (N=20), confined to the territory of the middle cerebral artery, occurring <6 months before the commencement of the study.

Intervention

The MT and control group participants underwent a patient-specific multidisciplinary rehabilitation program including conventional occupational therapy, physical therapy, and speech therapy for 5 d/wk, 6 h/d, over 3 weeks. The participants in the MT group received 1 hour of MT in addition to the conventional stroke rehabilitation.

Main Outcome Measures

The Upper Extremity Fugl-Meyer Assessment for motor recovery, Brunnstrom stages of motor recovery for the arm and hand, Box and Block Test for gross manual hand dexterity, and modified Ashworth scale to assess the spasticity.

Results

After 3 weeks of MT, mean change scores were significantly greater in the MT group than in the control group for the Fugl-Meyer Assessment (P=.008), Brunnstrom stages of motor recovery for the arm (P=.003) and hand (P=.003), and the Box and Block Test (P=.022). No significant difference was found between the groups for modified Ashworth scale (P=.647).

Conclusions

MT when combined with bilateral arm training and graded activities was effective in improving motor performance of the paretic upper limb after stroke compared with conventional therapy without MT.     

Attentional focus of feedback for improving performance of reach-to-grasp after stroke: a randomised crossover study

Objective

To investigate whether feedback inducing an external focus (EF) of attention (about movement effects) was more effective for retraining reach-to-grasp after stroke compared with feedback inducing an internal focus (IF) of attention (about body movement). It was predicted that inducing an EF of attention would be more beneficial to motor performance.

Design

Crossover trial where participants were assigned at random to two feedback order groups: IF followed by EF or EF followed by IF.

Setting

Research laboratory.

Participants

Forty-two people with upper limb impairment after stroke.

Intervention

Participants performed three reaching tasks: (A) reaching to grasp a jar; (B) placing a jar forwards on to a table; and (C) placing a jar on to a shelf. Ninety-six reaches were performed in total over one training session.

Main outcome measures

Kinematic measures were collected using motion analysis. Primary outcome measures were movement duration, peak velocity of the wrist, size of peak aperture and peak elbow extension.

Results

Feedback inducing an EF of attention produced shorter movement durations {first feedback order group: IF mean 2.53 seconds [standard deviation (SD) 1.85]; EF mean 2.12 seconds (SD 1.63), mean difference 0.41 seconds; 95% confidence interval -0.68 to 1.5; P = 0.008}, an increased percentage time to peak deceleration (P = 0.01) when performing Task B, and an increased percentage time to peak velocity (P = 0.039) when performing Task A compared with feedback inducing an IF of attention. However, an order effect was present whereby performance was improved if an EF of attention was preceded by an IF of attention.

Conclusions

Feedback inducing an EF of attention may be of some benefit for improving motor performance of reaching in people with stroke in the short term; however, these results should be interpreted with caution. Further research using a randomised design is recommended to enable effects on motor learning to be assessed.     

Self-Perceived Utilization of the Paretic Arm in Chronic Stroke Requires High Upper Limb Functional Ability

Objective

To explore potential predictors of self-reported paretic arm use at baseline and after task-specific training (TST) in survivors of stroke.

Design

Data were obtained from a randomized controlled trial of somatosensory stimulation and upper limb TST in chronic stroke.

Setting

University laboratory.

Participants

Chronic (≥3mo) survivors of stroke (N=33; mean age, 62y; mean stroke duration, 38mo).

Interventions

Participants received 12 sessions of TST preceded by either active (n=16) or sham (n=17) somatosensory stimulation to all 3 peripheral nerves.

Main Outcome Measures

Demographic and clinical characteristics were entered stepwise into multiple linear regression analyses to determine the factors that best predict baseline Motor Activity Log (MAL) amount of use rating and change 3 months after TST.

Results

The Action Research Arm Test (ARAT) score predicted the amount of use at baseline (R²=.47, P<.001); in using this model, an ARAT score of 54 (maximum of 57) is required to score 2.5 on the MAL (use described as between rarely and sometimes). After TST the change in the ARAT score predicted the change in the amount of use (R²=.31, P=.001). The predictive power of the model for change at 3 months increased if the Fugl-Meyer Assessment wrist component score was added (R²=.41, P=.001).

Conclusions

Utilization of the paretic upper limb in activities of daily living requires high functional ability. The increase in self-reported arm use after TST is dependent on the change in functional ability. These results provide further guidance for rehabilitation decisions.     

Quantification of Dry Needling and Posture Effects on Myofascial Trigger Points Using Ultrasound Shear-Wave Elastography

Objectives

To determine (1) whether the shear modulus in upper trapezius muscle myofascial trigger points (MTrPs) reduces acutely after dry needling (DN), and (2) whether a change in posture from sitting to prone affects the shear modulus.

Design

Ultrasound images were acquired in B mode with a linear transducer oriented in the transverse plane, followed by performance of shear-wave elastography (SWE) before and after DN and while sitting and prone.

Setting

University.

Participants

Women (N=7; mean age ± SD, 46±17y) with palpable MTrPs were recruited.

Intervention

All participants were dry needled in the prone position using solid filament needles that were inserted and manipulated inside the MTrPs. SWE was performed before and after DN in the sitting and prone positions.

Main Outcome Measure

MTrPs were evaluated by shear modulus using SWE.

Results

Palpable reductions in stiffness were noted after DN and in the prone position. These changes were apparent in the shear modulus map obtained with ultrasound SWE. With significant main effects, the shear modulus reduced from before to after DN (P<.01) and from the sitting to the prone position (P<.05). No significant interaction effect between time and posture was observed.

Conclusions

The shear modulus measured with ultrasound SWE reduced after DN and in the prone position compared with sitting, in agreement with reductions in palpable stiffness. These findings suggest that DN and posture have significant effects on the shear modulus of MTrPs, and that shear modulus measurement with ultrasound SWE may be sensitive enough to detect these effects.     

Muscle strength assessment in critically ill patients with handheld dynamometry: An investigation of reliability,minimal detectable change,and time to peak force generation

Purpose

Dynamometry is an objective tool for volitional strength evaluation that may overcome the limited sensitivity of the Medical Research Council scale for manual muscle tests, particularly at grades 4 and 5. The primary aims of this study were to investigate the reliability, minimal detectable change, and time to peak muscle force, measured with portable dynamometry, in critically ill patients.

Materials and methods

Isometric hand grip, elbow flexion, and knee extension were measured with portable dynamometry.

Results

Interrater consistency (intraclass correlation coefficient [95% confidence interval]) (0.782 [0.321-0.930] to 0.946 [0.840-0.982]) and test-retest agreement (0.819 [0.390-0.943] to 0.918 [0.779-0.970]) were acceptable for all dynamometry forces, with the exception of left elbow flexion. Despite generally good reliability, a mean change (upper 95% confidence interval) of 2.8 (7.8) kg, 1.9 (5.2) kg, and 2.6(7.1) kg may be required from a patient's baseline force measurement of right grip, elbow flexion, and knee extension to reflect real force changes. There was also a delay in the time for critically ill patients to generate peak muscle forces, compared with healthy controls (P ≤ .001).

Conclusions

Dynamometry can provide reliable measurements in alert critically ill patients, but moderate changes in strength may be required to overcome measurement error, during the acute recovery period. Deficits in force timing may reflect impaired neuromuscular control.     

Tendon properties and muscle architecture for knee extensors and plantar flexors in boys and men

Background

The purpose of this study was to compare the elastic properties and size of tendinous structures and muscle architecture for knee extensors and plantar flexors in boys and men.

Methods

Twenty-two early pubescent boys (9.6–12.7 yrs) and 23 young adult men (19.8–26.2 yrs) participated in this study. The maximal strain and thickness of tendinous structures for knee extensors and plantar flexors were measured using ultrasonography. In addition, the fascicle lengths of vastus lateralis and medial gastrocnemius muscles were measured.

Findings

The maximal strain of tendinous structures for plantar flexors was significantly greater in boys than in men, while there was no difference in the maximal strain for knee extensors between the two groups. The relative thickness (to body mass^1/3) of Achilles tendon was significantly greater in boys than in men, although there was no difference in that of patellar tendon between the two groups. The relative fascicle length (to limb length) of vastus lateralis muscle was significantly lower in boys than in men, although there was no difference in that of medial gastrocnemius muscle between the two groups.

Interpretation

These results suggest that the amount of changes in the elastic properties and sizes of tendinous structures and in the fascicle lengths from early pubescence to maturity is different for different muscle groups (in particular, the knee extensors and the plantar flexors).     

Movement characteristics of upper extremity prostheses during basic goal-directed tasks

Background

After an upper limb amputation a prosthesis is often used to restore the functionality. However, the frequency of prostheses use is generally low. Movement kinematics of prostheses use might suggest origins of this low use. The aim of this study was to reveal movement patterns of prostheses during basic goal-directed actions in upper limb prosthetic users and to compare this with existing knowledge of able-bodied performance during these actions.

Methods

Movements from six users of upper extremity prostheses were analyzed, three participants with a hybrid upper arm prosthesis, and three participants with a myoelectric forearm prosthesis. Two grasping tasks and a reciprocal pointing task were investigated during a single lab session. Analyses were carried out on the kinematics of the tasks.

Findings

When grasping, movements with both prostheses showed asymmetric velocity profiles of the reach and had a plateau in the aperture profiles. Reach and grasp were decoupled. Kinematics with the prostheses differed in that the use of upper arm prostheses required more time to execute the movements, while the movements were less smooth, more asymmetric, and showed more decoupling between reach and grasp. The pointing task showed for both prostheses less harmonic movements with higher task difficulty.

Interpretation

Characterizing prosthetic movement patterns revealed specific features of prosthetic performance. Developments in technology and rehabilitation should focus on these issues to improve prosthetic use, in particular on improving motor characteristics and the control of the elbow, and learning to coordinate the reach and the grasp component in prehension.