Effect of botulinum toxin injection in the rectus femoris on stiff-knee gait in people with stroke: a prospective observational study

Stoquart GG, Detrembleur C, Palumbo S, Deltombe T, Lejeune TM. Effect of botulinum toxin injection in the rectus femoris on stiff-knee gait in people with stroke: a prospective observational study.

Objective

To study the effect of botulinum toxin type A (BTX-A) injection in the rectus femoris on the decreased knee flexion during the swing phase of gait (stiff-knee gait) in people with stroke.

Design

Intervention study (before-after trial) with an observational design.

Setting

Outpatient rehabilitation clinic and gait laboratory.

Participants

Nineteen chronic hemiparetic adults presenting with stiff-knee gait.

Intervention

Injection of 200U of BTX-A (Botox) into the rectus femoris.

Main Outcome Measures

Before and 2 months after BTX-A rectus femoris injection: Stroke Impairment Assessment Set (SIAS), Duncan-Ely test, and an instrumented gait analysis.

Results

Median SIAS score improved from 53 (range, 36−65) to 57 (range, 42−70) (signed-rank test, P=.005) and the Duncan-Ely score from 3 (range, 1−3) to 1 (range, 0−3) (P<.001). In gait analysis, mean (± standard deviation) maximum knee flexion improved from 26°±13° to 31°±14° during the swing phase (paired t test, P<.001), knee flexion speed at toe-off improved from 82°±63° to 112°±75°/s (P=.009), and knee negative joint power (eccentric muscular contraction) improved from −.27±.23 to −.37±.26W/kg (P<.001). The 4 patients who almost did not flex the knee (<10°) before the BTX-A rectus femoris injection did not improve after the injection. The other 14 patients who flexed the knee more than 10° before the BTX-A rectus femoris injection decreased the walking energy cost from 5.4±1.6 to 4.6±1.3J·kg⁻¹·m⁻¹ (P=.006).

Conclusions

BTX-A rectus femoris injection may be beneficial in patients with a stiff-knee gait after stroke, particularly in patients with some knee flexion (>10°).     

Effect of Respiration on the Static Rear Stability of Wheelchairs

Kirby RL, Heimrath O, Stewart A, Smith C, MacLeod DA. Effect of respiration on the static rear stability of wheelchairs.

Objective

To test the hypothesis that the static rear stability of an occupied wheelchair is greater during full inspiration than expiration.

Design

Within-subject comparisons.

Setting

Rehabilitation center.

Participants

Able-bodied participants (N=10).

Intervention

None.

Main Outcome Measures

We measured the static rear stability (brakes unlocked) of an occupied wheelchair on a test platform according to International Organization for Standardization standards. We also used the Exhalation Threshold Test. The Exhalation Threshold Test was positive if, having been positioned at the maximum degree of platform tilt needed to maintain stability during full inspiration, the wheelchair tipped backward when the participant exhaled.

Results

The mean static rear stability values at full inspiration and expiration ± SD were 16.5°±2.3° and 16.1°±2.4°, with a mean difference of .46°±.24° (3%; P=.002). The Exhalation Threshold Test was positive in 19 (95%) of 20 trials.

Conclusions

Respiration has a slight but statistically significant effect on the rear stability of occupied wheelchairs, with greater stability at full inspiration. This has potential clinical implications for stability testing and the training of wheelchair skills, but further study is needed.     

Evaluation of pushrim-activated power-assisted wheelchairs using ANSI/RESNA standards

Karmarkar A, Cooper RA, Liu H, Connor S, Puhlman J. Evaluation of pushrim-activated power-assisted wheelchairs using ANSI/RESNA standards.

Objective

To determine and compare performance of pushrim-activated power-assisted wheelchairs (PAPAW) (iGLIDE, e-motion, Xtender) on national standards.

Design

Engineering performance and safety evaluation.

Setting

A Veteran Affairs and university-based research center.

Specimens

Nine PAPAWs.

Interventions

Not applicable.

Main Outcome Measures

Static, dynamic stability, brake effectiveness, maximum speed, acceleration, retardation, energy consumption, static, impact, and fatigue strength.

Results

There was no significant difference among the 3 models in forward stability. The iGLIDE was the most stable, whereas the e-motion was the least stable model in the rearward stability tests. All PAPAWs performed equally on the slopes of 3° and 6° in the forward and rearward directions. Braking distance was the highest for e-motion (5.64±0.28m) and the lowest (1.13±0.03m) for the iGLIDE in forward direction. The average equivalent cycles of all PAPAWs were 318,292±112,776.6 cycles (n=8) on the fatigue tests. All PAPAWs passed the impact and static strength tests.

Conclusions

The standards of the American National Standards Institute and the Rehabilitation Engineering and Assistive Technology Society of North America could act as quality assurance tool for wheelchairs. The standards for wheelchairs were first approved in 1990; after 17 years, exceeding the minimum values in the standards would be a reasonable expectation.     

Comparison of surface cooling and invasive cooling for rapid induction of mild therapeutic hypothermia in pigs--effectiveness of two different devices

Aim of the study

The effectiveness and safety of non-invasive surface cooling was compared to invasive endovascular cooling in an animal model.

Methods

Eight healthy pigs (29-38 kg) were cooled twice, starting in the first 4 pigs with unique surface cooling pads followed by endovascular cooling. In the second 4 pigs the order was reversed. The goal was to quickly lower pulmonary artery temperature from 38 to 33 °C. A paired t-test was used to compare cooling rates (°C/h, mean ± standard deviation) between both cooling techniques.

Results

Mean non-invasive surface cooling rate (11.9 ± 3.8 °C/h) significantly exceeded mean invasive cooling rate (3.9 ± 0.7 °C/h; p < 0.001). The mean difference in cooling rates was 8.0 ± 3.6 °C/h. No surface cooling related adverse skin reactions were observed.

Conclusions

Surface cooling is a simple method for achieving fast cooling rates. In our animal model, non-invasive cooling was three times faster than rapid endovascular cooling without overshoot.     

Design and Evaluation of a New Bladder Volume Monitor

Wang J, Hou C, Zheng X, Zhang W, Chen A, Xu Z. Design and evaluation of a new bladder volume monitor.

Objective

To introduce and evaluate a new implantable bladder volume monitor.

Design

Experimental study.

Setting

Animal laboratory.

Animals

Eight dogs.

Interventions

A coin-shaped permanent magnet was stitched onto the anterior bladder wall and a magnetic field sensor was fixed onto the lower abdominal external wall in 8 male dogs. The bladder was filled with sterile normal saline in consecutive steps of 25mL each from 0 to 200mL by a transurethral catheter.

Main Outcome Measure

Sensor readings were recorded after each step of bladder filling.

Results

The sensor baseline was set at 70° when the bladder was empty. After filling the bladders with 25, 50, 75, 100, 125, 150, 175, and 200mL saline water, the sensor readings were 74.6±0.9°, 79.6±1.2°, 84.5±0.9°, 90.1±0.8°, 95.5±1.1°, 101.8±2.1°, 110.5±2.9°, and 121.9±3.5°, respectively. Sensor readings were positively correlated with bladder volume (r=1; P<.01).

Conclusions

The design of a new bladder volume monitor that is made up of an external magnetic field sensor and an internal permanent magnet is reasonable and feasible. The new bladder volume monitor is simple in structure.     

Effect of wheelchair tilt-in-space and recline angles on skin perfusion over the ischial tuberosity in people with spinal cord injury

Jan Y-K, Jones MA, Rabadi MH, Foreman RD, Thiessen A. Effect of wheelchair tilt-in-space and recline angles on skin perfusion over the ischial tuberosity in people with spinal cord injury.

Objective

To investigate the efficacy of wheelchair tilt-in-space and recline on enhancing skin perfusion over the ischial tuberosity in wheelchair users with spinal cord injury (SCI).

Design

Repeated-measures, intervention, and outcomes-measure design.

Setting

A university research laboratory.

Participants

Wheelchair users with SCI (N=11; 9 men, 2 women; mean ± SD age, 37.7±14.2y; body mass index, 24.7±2.6kg/m²; duration of injury, 8.1±7.5y).

Interventions

Protocols (N=6) of various wheelchair tilt-in-space and recline angles were randomly assigned to participants. Each protocol consisted of a 5-minute sitting-induced ischemic period and a 5-minute wheelchair tilt-in-space and recline pressure-relieving period. Participants sat in a position without tilt or recline for 5 minutes and then sat in 1 of 6 wheelchair tilted and reclined positions, including (1) 15° tilt-in-space and 100° recline, (2) 25° tilt-in-space and 100° recline, (3) 35° tilt-in-space and 100° recline, (4) 15° tilt-in-space and 120° recline, (5) 25° tilt-in-space and 120° recline, and (6) 35° tilt-in-space and 120° recline. A 5-minute washout period (at 35° tilt-in-space and 120° recline) was allowed between protocols.

Main Outcome Measures

Laser Doppler flowmetry was used to measure skin perfusion over the ischial tuberosity in response to changes in body positions caused by performing wheelchair tilt-in-space and recline. Skin perfusion response to wheelchair tilt-in-space and recline was normalized to skin perfusion of the upright seated position (no tilt/recline).

Results

Combined with 100° recline, wheelchair tilt-in-space at 35° resulted in a significant increase in skin perfusion compared with the upright seated position (no tilt/recline; P<.05), whereas there was no significant increase in skin perfusion at 15° and 25° tilt-in-space (not significant). Combined with 120° recline, wheelchair tilt-in-space at 15°, 25°, and 35° showed a significant increase in skin perfusion compared with the upright seated position (P<.05).

Conclusions

Our results indicate that wheelchair tilt-in-space should be at least 35° for enhancing skin perfusion over the ischial tuberosity when combined with recline at 100° and should be at least 25° when combined with recline at 120°. Although smaller angles of wheelchair tilt-in-space and recline are preferred by wheelchair users for functional purposes, wheelchair tilt-in-space less than 25° and recline less than 100° may not be sufficient for effective pressure reduction for enhancing skin perfusion over the ischial tuberosity in people with SCI.     

Validity of a Functional Dynamic Walking Test for the Elderly

Lark SD, Pasupuleti S. Validity of a functional dynamic walking test for the elderly.

Objective

To determine the validity of a safe, quick, and simple method of measuring dynamic balance in the elderly during gait called the parallel walk test.

Design

Control study.

Setting

Outpatient clinic, community.

Participants

Twenty-seven elderly fallers (age 82±6y) registered at a falls clinic and 34 elderly nonfallers (age 76±7y) were recruited to this study based on Mini Mental State Examination and Barthel Index scores.

Interventions

Subjects were timed as they walked 6m between 2 parallel lines on the floor at 3 different widths (20, 30.5, 38cm) in their own footwear. They were scored for foot placement on the line (1 point) or outside the lines (2 points). Participants also performed a timed 6-m tandem walk test, a 30-second tandem stance, and a 30-second parallel stance.

Main Outcome Measures

Scores and time to complete the parallel walk test and tandem walk test along with the time of standing for tandem and parallel stance. Validity coefficients were calculated for the sensitivity and specificity of the parallel walk test.

Results

All subjects completed the parallel walk test, but few attempted and completed the tandem walk test. The fallers had significantly greater scores at 20 and 30.5cm and took significantly longer to complete the 6m at all widths. The 20-cm width was most discriminatory. The parallel walk test showed a significant correlation with the tandem stance.

Conclusions

All subjects attempted and completed the parallel walk test but not the tandem walk test. The time to completion and scoring accurately measures dynamic balance during gait in elderly fallers. The parallel walk test could be a useful tool in the clinical setting for assessing balance in gait pre- and postintervention.     

Biphasic DC shock cardioverting doses for paediatric atrial dysrhythmias

Objective

To determine cardioversion doses of biphasic DC shock for paediatric atrial dysrhythmias.

Design

Prospective recording of energy, pre-shock and post-shock rhythms.

Setting

Paediatric hospital.

Patients

Shockable atrial dysrhythmias.

Main results

Forty episodes of atrial dysrhythmias among 25 children (mean age 6.8 ± 7.1 years, mean weight 28.2 ± 28.5 kg) were treated with external shock. The first shock converted the dysrhythmia to sinus rhythm in 25 episodes. Cardioversion occurred in 2 of 8 (25%) episodes with a dose of <0.5 J/kg, 14 of 16 (88%) with a dose of 0.5-1.0 J/kg and 9 of 16 (56%) with a dose of >1.0 J/kg (p = 0.01, Fisher's exact test). Ten of 15 initially non-responsive episodes were cardioverted with additional shocks at 1.1 ± 0.6 J/kg (range 0.5-2.1 J/kg). Of the remaining 5 unresponsive episodes, 2 of ventricular fibrillation (induced by unsynchronized shock) were successfully defibrillated, and 3 were managed with cardiopulmonary bypass. Among 11 additional children (mean age 4.3 ± 6.8 years, mean weight 18.1 ± 22.0 kg), 18 episodes of atrial dysrhythmias were treated with internal shock which successfully cardioverted all episodes with one or more shocks at 0.4 ± 0.2 J/kg.

Conclusions

In rounded doses, recommended initial external cardioversion doses are 0.5-1.0 J/kg and subsequently up to 2 J/kg, internal cardioversion doses are 0.5 J/kg.     

Stability Limits, Single-Leg Jump, and Body Awareness in Older Tai Chi Practitioners

Gyllensten AL, Hui-Chan CWY, Tsang WWN. Stability limits, single-leg jump, and body awareness in older Tai Chi practitioners.

Objective

To compare stability limits, single-leg jumping, and body awareness in older Tai Chi practitioners and healthy older controls and to determine possible interrelationships among these variables.

Design

Cross-sectional study.

Setting

University-based rehabilitation center.

Participants

Tai Chi practitioners (n=24; age±SD, 68.5±6.6y) and control subjects (n=20; age, 71.3±6.7y) were recruited.

Interventions

Not applicable.

Main Outcome Measures

Measures included the following: (1) subjects' intentional weight shifting to 8 different spatial positions within their base of support using the limits of stability test, (2) the ability to leave the floor in single-leg jumping and to maintain balance on landing using force platform measurements, and (3) body awareness and movement behaviors using the Body Awareness Scale-Health (BAS-H).

Results

The findings showed that Tai Chi practitioners had a significantly better ability to lean further without losing stability and better directional control (P<0.01). They had a better ability to jump off the floor (P<0.05) and to maintain a longer single-leg stance after landing (P<.05) and better overall body awareness (P<.001). The single-leg jumps also correlated significantly with limits of stability measures of movement velocity, endpoint excursions, and maximum excursions but not with directional control. The BAS-H scores correlated significantly with the limits of stability measures except directional control. They also correlated significantly with the ability to jump off the floor and maintain stability after landing.

Conclusions

When compared with healthy controls, Tai Chi practitioners had better stability limits, increased ability to perform a single-leg jump, and more stability in landing on 1 leg as well as better body awareness. Significant correlations among limits of stability measures, single-leg jumping tests, and the BAS-H scores indicate the importance of body awareness in limits of stability, single-leg jumping, and landing.     

Proprioception of the shoulder after stroke

Niessen MH, Veeger DH, Koppe PA, Konijnenbelt MH, van Dieën J, Janssen TW. Proprioception of the shoulder after stroke.

Objective

To investigate position sense and kinesthesia of the shoulders of stroke patients.

Design

Case-control study.

Setting

A rehabilitation center.

Participants

A total of 22 inpatients with stroke and 10 healthy control subjects.

Interventions

Not applicable.

Main Outcome Measures

Angular displacement (in degrees) for threshold to detection of passive motion (TDPM) tests and absolute error (in degrees) for passive reproduction of joint position tests.

Results

For patients, the TDPM for internal and external rotation was significantly higher for both the contralateral (paretic) side (internal, 7.92°±7.19°; external, 8.46°±8.87°) and the ipsilateral (nonparetic) side (internal, 4.86°±5.03°; external, 6.09°±9.15°) compared with the control group (internal, 1.83°±1.09°; external, 1.71°±.85°). Also, for internal rotation, TDPM was significantly higher for patients on the contralateral side compared with the ipsilateral side. For passive reproduction of joint position tests, no differences were found.

Conclusions

Both the contralateral and ipsilateral shoulders of stroke patients showed impaired TDPM. Passive reproduction of joint position does not seem to be affected as a result of a stroke. The control of the muscle spindles and central integration or processing problems of the afferent signals provided by muscle spindles might cause these effects.     

Effects of ankle joint mobilizations in adults poststroke: a pilot study

Kluding PM, Santos M. Effects of ankle joint mobilizations in adults poststroke: a pilot study.

Objective

To compare the effect of 2 interventions on ankle mobility, ankle kinematics, and weight-bearing symmetry during functional activities in subjects with hemiparesis after a stroke.

Design

Randomized trial.

Setting

Academic medical center.

Participants

A convenience sample of 16 subjects with hemiparesis after stroke (mean age, 55.2y; mean time since stroke, 21.4mo).

Intervention

Subjects received 8 sessions over 4 weeks of either functional task practice combined with ankle joint mobilizations, or functional task practice only.

Main Outcome Measures

Changes in ankle range of motion (ROM) (not blinded), ankle kinematics during sit-to-stand (STS) and gait, and lower-extremity weight-bearing symmetry during STS and static standing.

Results

The combined intervention group gained 5.7°±3.1° in passive ankle ROM compared with 0.2°±2.6° in the functional practice only group (95% confidence interval [CI], 2.5-8.6; P<.01). No significant changes in ankle kinematics or weight bearing during static standing were noted in either group. The functional practice group decreased differences in weight bearing during STS by 9.5%±6.47%, whereas the combined intervention group increased this difference by 3.37%±5.29% (95% CI, 3.26-19.46; P=.01).

Conclusions

The increase in ankle motion did not improve joint kinematics and may have prevented improvement in weight-bearing symmetry.     

Implanted Electrical Stimulation of the Trunk for Seated Postural Stability and Function After Cervical Spinal Cord Injury: A Single Case Study

Triolo RJ, Boggs L, Miller ME, Nemunaitis G, Nagy J, Bailey SN. Implanted electrical stimulation of the trunk for seated postural stability and function after cervical spinal cord injury: a single case study.

Objectives

To explore and quantify the physical and functional effects of stabilizing the torso with electrical stimulation of the paralyzed hip and trunk musculature after motor complete tetraplegia.

Design

Single-subject case study with repeated measures and concurrent controls.

Setting

Academic outpatient rehabilitation center.

Participants

Forty-four-year-old man with C4 American Spinal Injury Association grade A tetraplegia 20 years postspinal cord injury.

Intervention

A surgically implanted multichannel pulse generator and intramuscular stimulating electrodes to activate lumbar erector spinae, quadratus lumborum, and gluteus maximus muscles bilaterally.

Main Outcome Measures

Outcomes assessed with and without stimulation included (1) spinal alignment and pelvic orientation, (2) pulmonary function and ventilatory volumes, (3) forward bimanual reaching distance, (4) seated stability and resistance to externally applied disturbances, (5) maximal force and speed of rowing-like movements, and the ability to (6) independently return to an erect seated position from full forward or lateral flexion and (7) roll in bed without assistance.

Results

Stimulation improved spinal convexity and kyphosis by 26° and 21°, reduced posterior pelvic tilt by 11°, increased forced expiratory volume and vital capacity by 10% and 22%, and improved forward reach by more than 7cm. Average resistance to sagittal disturbances increased by more than 40% (P<.002), and mean force exerted during underhanded pulling more than doubled (P=.014) with stimulation. Restoration of upright sitting in both sagittal and coronal planes and bed turning was made possible through appropriately timed activation of the hip and trunk muscles.

Conclusions

A neuroprosthesis for controlling the paralyzed torso can positively impact spinal alignment, seated posture, pulmonary function, trunk stability, and reach. Stimulation of hip and trunk muscles can improve performance of activities of daily living as well as enable independent wheelchair and bed mobility.     

Lower Thoracic Spinal Cord Stimulation to Restore Cough in Patients With Spinal Cord Injury: Results of a National Institutes of Health-Sponsored Clinical Trial. Part I: Methodology and Effectiveness of Expiratory Muscle Activation

DiMarco AF, Kowalski KE, Geertman RT, Hromyak DR. Lower thoracic spinal cord stimulation to restore cough in patients with spinal cord injury: results of a National Institutes of Health-sponsored clinical trial. Part I: methodology and effectiveness of expiratory muscle activation.

Objective

Evaluation of the capacity of lower thoracic spinal cord stimulation (SCS) to activate the expiratory muscles and generate large airway pressures and high peak airflows characteristic of cough, in subjects with tetraplegia.

Design

Clinical trial.

Setting

Inpatient hospital setting for electrode insertion; outpatient setting for measurement of respiratory pressures; home setting for application of SCS.

Participants

Subjects (N=9; 8 men, 1 woman) with cervical spinal cord injury and weak cough.

Interventions

A fully implantable electrical stimulation system was surgically placed in each subject. Partial hemilaminectomies were made to place single-disk electrodes in the epidural space at the T9, T11, and L1 spinal levels. A radiofrequency receiver was placed in a subcutaneous pocket over the anterior portion of the chest wall. Electrode wires were tunneled subcutaneously and connected to the receiver. Stimulation was applied by activating a small portable external stimulus controller box powered by a rechargeable battery to each electrode lead alone and in combination.

Main Outcome Measures

Peak airflow and airway pressure generation achieved with SCS.

Results

Supramaximal SCS resulted in high peak airflow rates and large airway pressures during stimulation at each electrode lead. Maximum peak airflow rates and airway pressures were achieved with combined stimulation of any 2 leads. At total lung capacity, mean maximum peak airflow rates and airway pressure generation were 8.6±1.8 (mean ± SE) L/s and 137±30 cmH₂O (mean ± SE), respectively.

Conclusions

Lower thoracic SCS results in near maximum activation of the expiratory muscles and the generation of high peak airflow rates and positive airway pressures in the range of those observed with maximum cough efforts in healthy persons.     

Construct Validity and Test-Retest Reliability of the Climbing Stairs Questionnaire in Lower-Limb Amputees

de Laat FA, Rommers GM, Geertzen JH, Roorda LD. Construct validity and test-retest reliability of the Climbing Stairs Questionnaire in lower-limb amputees.

Objective

To investigate the construct validity and test-retest reliability of the Climbing Stairs Questionnaire, a patient-reported measure of activity limitations in climbing stairs, in lower-limb amputees.

Design

A cross-sectional study.

Setting

Outpatient department of a rehabilitation center.

Participants

Lower-limb amputees (N=172; mean ± SD age, 65±12y; 71% men; 82% vascular cause) participated in the study; 33 participated in the reliability study.

Interventions

Not applicable.

Main Outcome Measure(s)

Construct validity was investigated by testing 10 hypotheses: limitations in climbing stairs according to the Climbing Stairs Questionnaire will be greater in lower-limb amputees who: (1) are older, (2) have a vascular cause of amputation, (3) have a bilateral amputation, (4) have a higher level of amputation, (5) have more comorbid conditions, (6) had their rehabilitation treatment in a nursing home, and (7) climb fewer flights of stairs. Furthermore, limitations in climbing stairs will be related positively to activity limitations according to: (8) the Locomotor Capabilities Index, (9) the Questionnaire Rising and Sitting down, and (10) the Walking Questionnaire. Construct validity was quantified by using the Mann-Whitney U test, Kruskal-Wallis test, and Spearman correlation coefficient. Test-retest reliability was assessed with a 3-week interval and quantified using the intraclass correlation coefficient (ICC).

Results

Construct validity (8 of 10 null hypotheses not rejected) and test-retest reliability were good (ICC=.79; 95% confidence interval, .57-.90).

Conclusion

The Climbing Stairs Questionnaire has good construct validity and test-retest reliability in lower-limb amputees.     

Effect of Taping on Actual and Perceived Dynamic Postural Stability in Persons With Chronic Ankle Instability

Delahunt E, McGrath A, Doran N, Coughlan GF. Effect of taping on actual and perceived dynamic postural stability in persons with chronic ankle instability.

Objective

To investigate whether 2 different mechanisms of ankle joint taping ([1] lateral subtalar sling or [2] fibular repositioning) can enhance actual and perceived dynamic postural stability in participants with chronic ankle instability (CAI).

Design

Laboratory-based repeated-measures study.

Setting

University biomechanics laboratory.

Participants

Participants (n=16) with CAI.

Interventions

Participants performed the Star Excursion Balance Test (SEBT) under 3 different conditions: (1) no tape, (2) lateral subtalar sling taping and (3) fibular repositioning taping.

Main Outcome Measures

Reach distances in the anterior, posteromedial, and posterolateral directions on the SEBT. Participants' perceptions of stability, confidence, and reassurance when performing the SEBT under 2 different taping conditions.

Results

Taping did not improve reach distance on the SEBT (P>.05). Feelings of confidence increased for 56% of participants (P=.002) under both tape conditions. Feelings of stability increased for 87.5% of participants (P<.001) using condition 2 (lateral subtalar sling taping) and 75% of participants (P=.001) using condition 3 (fibular repositioning taping). Feelings of reassurance increased for 68.75% of participants (P=.001) using condition 2 (lateral subtalar sling taping) and 50% of participants (P=.005) using condition 3 (fibular repositioning taping).

Conclusions

No significant change in dynamic postural stability was observed after application of either taping mechanism; however, participants' perceptions of confidence, stability, and reassurance were significantly improved. Further research is necessary to fully elucidate the exact mechanisms by which taping may help reduce the incidence of repeated injury in subjects with CAI.     

Changes in Passive Mechanical Properties of the Gastrocnemius Muscle at the Muscle Fascicle and Joint Levels in Stroke Survivors

Gao F, Grant TH, Roth EJ, Zhang L-Q. Changes in passive mechanical properties of the gastrocnemius muscle at the muscle fascicle and joint levels in stroke survivors.

Objectives

To investigate the ankle joint-level and muscle fascicle-level changes and their correlations in stroke survivors with spasticity, contracture, and/or muscle weakness at the ankle.

Design

To investigate the fascicular changes of the medial gastrocnemius muscle using ultrasonography and the biomechanical changes at the ankle joint across 0°, 30°, 60°, and 90° knee flexion in a case-control manner.

Setting

Research laboratory in a rehabilitation hospital.

Participants

Stroke survivors (n=10) with ankle spasticity/contracture and healthy control subjects (n=10).

Interventions

Not applicable.

Main Outcome Measurements

At the muscle fascicle level, medial gastrocnemius muscle architecture including the fascicular length, pennation angle, and thickness were evaluated in vivo with the knee and ankle flexion changed systematically. At the joint level, the ankle range of motion (ROM) and stiffness were determined across the range of 0° to 90° knee flexion.

Results

At comparable joint positions, stroke survivors showed reduced muscle fascicle length, especially in ankle dorsiflexion (P≤.048) and smaller pennation angle, especially for more extended knee positions (P≤.049) than those of healthy control subjects. At comparable passive gastrocnemius force, stroke survivors showed higher fascicular stiffness (P≤.044) and shorter fascicle length (P≤.025) than controls. The fascicle-level changes of decreased muscle fascicle length and pennation angle and increased medial gastrocnemius fascicle stiffness in stroke were correlated with the joint level changes of increased joint stiffness and decreased ROM (P<.05).

Conclusions

This study evaluated specific muscle fascicular changes as mechanisms underlying spasticity, contracture, and joint-level impairments, which may help improve stroke rehabilitation and outcome evaluation.     

Test position and hip strength in healthy adults and people with chronic stroke

Barbic S, Brouwer B. Test position and hip strength in healthy adults and people with chronic stroke.

Objective

To determine if peak torques generated by the hip flexors and extensors are dependent on test position in healthy adults and in people with chronic stroke.

Design

Cross-sectional study.

Setting

Motor performance laboratory.

Participants

Volunteers were 10 young (20.7±1.5y), 10 older adults (62.1±7y), and 10 stroke survivors (60.6±10y) who were an average of 5 years poststroke.

Interventions

Not applicable.

Main Outcome Measures

Isokinetic (60°/s) peak concentric hip flexor and extensor torques (in Nm/kg) generated in supine and standing positions.

Results

Peak flexor torques measured in standing were generally higher than in supine (P=.018); a pattern evident in all groups, but significant only in stroke. An interaction between test position and group for hip extensor strength (P=.016) reflected 2 distinct patterns in which torques were highest in standing among the young subjects and highest in supine after stroke.

Conclusions

Isokinetic hip flexor and extensor strength measured in standing and supine are comparable in young and older healthy people. In chronic stroke, the test position may over or underestimate maximum peak torque depending on the muscle group tested, particularly on the side ipsilateral to the lesion. These findings may have implications for predicting functional ability from strength measurements.     

Physical Function, Gait, and Dynamic Balance of Transfemoral Amputees Using Two Mechanical Passive Prosthetic Knee Devices

Lythgo N, Marmaras B, Connor H. Physical function, gait, and dynamic balance of transfemoral amputees using two mechanical passive prosthetic knee devices.

Objective

To investigate the effect of the 3R90 and 3R92 (Otto Bock Healthcare) mechanical passive prosthetic knee devices on the physical function, gait, and dynamic balance (sudden stop and turn) of transfemoral amputees.

Design

Intervention study with crossover design.

Setting

University research center.

Participants

Men (N=5; mean age ± SD, 58.8±11.9y) with unilateral transfemoral amputation.

Intervention

Prosthetic knee joints (N=2; 3R90 and 3R92). Acclimatization ranged from 14 to 47 days (25.5±9.3d).

Main Outcome Measures

Physical function, gait, dynamic balance.

Results

The Timed Up and Go Test, 6-Minute Walk Test, and Four Square Step Test measures improved with the 3R92. Total scores on the Prosthesis Evaluation Questionnaire were similar for the 3R92 (82.0±6.3) and the participant's own or original device (83.9±4.8). These devices were rated higher than the 3R90 (65.5±16.8). Compared with the original device, gait velocity was significantly slower (5cm/s; P=.017) with the 3R92, but was unchanged for the 3R90. This difference was not considered clinically significant because the effect size was small (0.2). No other significant gait differences were found. Large temporal gait asymmetries observed with the original device remained with the 3R90 and 3R92 (step, ≈20%; single support, ≈30%; stance, ≈19%). Although no significant differences were found for the sudden-turn or sudden-stop tasks, the sudden-turn group success rates were highest with the original devices.

Conclusions

Gait and symmetry measures were unchanged. Gait speed was slower with the 3R92, but this was not considered to be clinically significant. Sudden-turn success rates generally were higher with the original devices. A crossover stepping movement was more difficult to implement than a side-stepping movement during sudden turns.     

Effect of Hamstring Flexibility on Hip and Lumbar Spine Joint Excursions During Forward-Reaching Tasks in Participants With and Without Low Back Pain

Johnson EN, Thomas JS. Effect of hamstring flexibility on hip and lumbar spine joint excursions during forward-reaching tasks in participants with and without low back pain.

Objective

To examine the correlation between hamstring flexibility and hip and lumbar spine joint excursions during standardized reaching and forward-bending tasks.

Design

Retrospective analysis of data obtained during 2 previous prospective studies that examined kinematics and kinetics during forward-reaching tasks in participants with and without low back pain (LBP).

Setting

The 2 previous studies were conducted in the Motor Control Lab at Ohio University and the Orthopaedic Ergonomics Laboratory at The Ohio State University.

Participants

Data from a total of 122 subjects from 2 previous studies: study 1: 86 subjects recovered from an episode of acute LBP (recovered) and study 2 (A.I. McCallum, unpublished data): 18 chronic LBP subjects and 18 healthy-matched controls (healthy).

Interventions

Not applicable.

Main Outcome Measure

Correlation values between hamstring flexibility as measured by straight leg raise (SLR) and amount of hip and lumbar spine joint excursions used during standardized reaching and forward-bending tasks.

Results

No significant correlation was found between hamstring flexibility and hip and lumbar joint excursions during forward-bending tasks in the LBP or recovered groups. The SLR had a significant negative correlation with lumbar spine excursions during reaching tasks to a low target in the healthy group (right SLR: P=.011, left SLR: P=.004).

Conclusions

Hamstring flexibility is not strongly related to the amount of lumbar flexion used to perform forward-reaching tasks in participants who have chronic LBP or who have recovered from LBP. More research needs to be conducted to examine the influence of hamstring flexibility on observed movement patterns to further evaluate the efficacy of flexibility training in the rehabilitation of patients with LBP.     

Proprioceptive acuity in active rotation movements in healthy knees

Muaidi QI, Nicholson LL, Refshauge KM. Proprioceptive acuity in active rotation movements in healthy knees.

Objectives

To investigate the ability of asymptomatic participants to discriminate between active knee rotation movements of different magnitude and to determine whether proprioceptive acuity of active knee rotation differs between limbs (dominant and nondominant and right and left).

Design

Cross-sectional study.

Setting

Laboratory in an Australian university.

Participants

Healthy volunteers (N=30) without previous cruciate ligament injury or surgery, previous fracture of the lower limbs, or other lower-limb disorders in the last 3 months.

Interventions

Not applicable.

Main Outcome Measures

Knee rotation proprioceptive acuity was determined by using our custom-designed device. The measure of proprioceptive acuity used in this study was the just-noticeable difference (JND). Participants actively rotated the knee (internal or external rotation) to 1 of 4 movement blocks and judged the magnitude of the permitted motion. Proprioceptive acuity scores, representing a participant’s ability to detect small differences in magnitude of active knee rotation movements, were then calculated.

Results

The means of the JND for proprioceptive acuity of internal rotation (1.37°±.11°) were significantly (P=.04) lower than for external rotation (1.6°±.14°) regardless of side (right, left) or dominance. No significant difference was found between the mean JND for left and right knee rotations (P=.84) or between the mean JND for dominant and nondominant knee rotation (P=.69).

Conclusions

Participants perceived smaller differences between active internal rotation movements than external rotation. No significant difference was found between the dominant and nondominant leg or between the left and right leg; therefore, clinicians can establish whether a proprioceptive deficit exists after unilateral injury and can use acuity of the uninjured knee as a normal status for rehabilitation.