Combined use of body weight support, functional electric stimulation, and treadmill training to improve walking ability in individuals with chronic incomplete spinal cord injury

Is body weight-support treadmill training effective in increasing muscle trophism after traumatic spinal cord injury? A systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine the effectiveness of body weight-support treadmill training (BWSTT) for muscle atrophy management in people with spinal cord injury (SCI).

SETTING

Studies from multiple countries were included.

METHODS

The following databases were consulted from January to October 2013: PubMed, Institute for Scientific Information (ISI), Science Direct and Lilacs. The methodological quality of the articles included was classified according to Jovell and Navarro-Rubio.

RESULTS

A total of five studies were included. These studies reported a significant association between BWSTT and increased trophism of the lower limb muscles of humans with SCI, which was observed as an increase in the cross-sectional area. Moreover, improvements in the ability to generate peak torque, contract the knee extensors and ankle plantarflexors with reduction of body weight support were observed after BWSTT.

CONCLUSION

The results were considered inconclusive because of the low methodological quality of the articles, which was because of the absence of sample homogeneity, thereby providing a low level of evidence for clinical practice.

Adverse events in cardiovascular-related training programs in people with spinal cord injury: a systematic review

CONTEXT

There are anecdotal reports of adverse events (AEs) associated with exercise in people with spinal cord injury (SCI) and consequent concern by people with SCI and their providers about potential risks of exercise. Enumeration of specific events has never been performed and the extent of risk of exercise to people with SCI is not understood.

OBJECTIVE

To systematically review published evidence to identify and enumerate reports of adverse events or AEs associated with training in persons with SCI.

METHODS

Review was limited to peer-reviewed studies published in English from 1970 to 2011: (1) in adults with SCI, (2) evaluating training protocols consisting of repeated sessions over at least 4 weeks to maintain or improve cardiovascular health, (3) including volitional exercise modalities and functional electrical stimulation (FES)-enhanced exercise modalities, and (4) including a specific statement about AEs. Trained reviewers initially identified a total of 145 studies. After further screening, 38 studies were included in the review. Quality of evidence was evaluated using established procedures.

RESULTS

There were no serious AEs reported. There were no common AEs reported across most types of interventions, except for musculoskeletal AEs related to FES walking. There were few AEs in volitional exercise studies.

CONCLUSION

There is no evidence to suggest that cardiovascular exercise done according to guidelines and established safety precautions is harmful. To improve the strength of these conclusions, future publications should include definition of AEs, information about pre-intervention screening, and statements of the nature and extent of AEs.

A randomized trial of functional electrical stimulation for walking in incomplete spinal cord injury: Effects on walking competency

BACKGROUND

Multi-channel surface functional electrical stimulation (FES) for walking has been used to improve voluntary walking and balance in individuals with spinal cord injury (SCI).

OBJECTIVE

To investigate short- and long-term benefits of 16 weeks of thrice-weekly FES-assisted walking program, while ambulating on a body weight support treadmill and harness system, versus a non-FES exercise program, on improvements in gait and balance in individuals with chronic incomplete traumatic SCI, in a randomized controlled trial design.

METHODS

Individuals with traumatic and chronic (≥18 months) motor incomplete SCI (level C2 to T12, American Spinal Cord Injury Association Impairment Scale C or D) were recruited from an outpatient SCI rehabilitation hospital, and randomized to FES-assisted walking therapy (intervention group) or aerobic and resistance training program (control group). Outcomes were assessed at baseline, and after 4, 6, and 12 months. Gait, balance, spasticity, and functional measures were collected.

RESULTS

Spinal cord independence measure (SCIM) mobility sub-score improved over time in the intervention group compared with the control group (baseline/12 months: 17.27/21.33 vs. 19.09/17.36, respectively). On all other outcome measures the intervention and control groups had similar improvements. Irrespective of group allocation walking speed, endurance, and balance during ambulation all improved upon completion of therapy, and majority of participants retained these gains at long-term follow-ups.

CONCLUSIONS

Task-oriented training improves walking ability in individuals with incomplete SCI, even in the chronic stage. Further randomized controlled trials, involving a large number of participants are needed, to verify if FES-assisted treadmill training is superior to aerobic and strength training.

Activity-based therapy for recovery of walking in individuals with chronic spinal cord injury: results from a randomized clinical trial

OBJECTIVE

To examine the effects of activity-based therapy (ABT) on neurologic function, walking ability, functional independence, metabolic health, and community participation.

DESIGN

Randomized controlled trial with delayed treatment design.

SETTING

Outpatient program in a private, nonprofit rehabilitation hospital.

PARTICIPANTS

Volunteer sample of adults (N=48; 37 men and 11 women; age, 18-66y) with chronic (≥12mo postinjury), motor-incomplete (ASIA Impairment Scale grade C or D) spinal cord injury (SCI).

INTERVENTIONS

A total of 9h/wk of ABT for 24 weeks including developmental sequencing; resistance training; repetitive, patterned motor activity; and task-specific locomotor training. Algorithms were used to guide group allocation, functional electrical stimulation utilization, and locomotor training progression.

MAIN OUTCOME MEASURES

Neurologic function (International Standards for Neurological Classification of Spinal Cord Injury); walking speed and endurance (10-meter walk test, 6-minute walk test, and Timed Up and Go test); community participation (Spinal Cord Independence Measure, version III, and Reintegration to Normal Living Index); and metabolic function (weight, body mass index, and Quantitative Insulin Sensitivity Check).

RESULTS

Significant improvements in neurologic function were noted for experimental versus control groups (International Standards for Neurological Classification of Spinal Cord Injury total motor score [5.1±6.3 vs 0.9±5.0; P=.024] and lower extremity motor score [4.2±5.2 vs -0.6±4.2; P=.004]). Significant differences between experimental and control groups were observed for 10-meter walk test speed (0.096±0.14m/s vs 0.027±0.10m/s; P=.036) and 6-minute walk test total distance (35.97±48.2m vs 3.0±25.5m; P=.002).

CONCLUSIONS

ABT has the potential to promote neurologic recovery and enhance walking ability in individuals with chronic, motor-incomplete SCI. However, further analysis is needed to determine for whom ABT is going to lead to meaningful clinical benefits.

Inter- and intralimb adaptations to a sensory perturbation during activation of the serotonin system after a low spinal cord transection in neonatal rats

Activation of the serotonin system has been shown to induce locomotor activity following a spinal cord transection. This study examines how the isolated spinal cord adapts to a sensory perturbation during activation of the serotonergic system. Real-time and persistent effects of a perturbation were examined in intact and spinal transected newborn rats. Rats received a spinal surgery (sham or low thoracic transection) on postnatal day 1 and were tested 9 days later. At test, subjects were treated with the serotonergic receptor agonist quipazine (3.0 mg/kg) to induce stepping behavior. Half of the subjects experienced range of motion (ROM) restriction during stepping, while the other half did not. Differences in stepping behavior (interlimb coordination) and limb trajectories (intralimb coordination) were found to occur in both intact and spinal subjects. Adaptations were seen in the forelimbs and hindlimbs. Also, real-time and persistent effects of ROM restriction (following removal of the perturbation) were seen in ROM-restricted subjects. This study demonstrates the sensitivity of the isolated spinal cord to sensory feedback in conjunction with serotonin modulation.

Comparison of body weight-supported treadmill training versus body weight-supported overground training in people with incomplete tetraplegia: a pilot randomized trial

Objective:

To compare the effectiveness of body weight-supported treadmill training and body weight-supported overground training for improving gait and strength in people with traumatic incomplete tetraplegia.

Design:

Assessor blinded randomized trial.

Setting:

Rehabilitation institute of a tertiary care teaching hospital in India.

Participants:

Sixteen participants with traumatic motor incomplete tetraplegia and within two years of injury.

Interventions:

Participants were randomised to one of two groups: body weight-supported overground training on level ground and body weight-supported treadmill training. Both groups received 30 minutes of gait training per day, five days a week for eight weeks. In addition, both groups received regular rehabilitation which included flexibility, strength, balance, self care and functional training.

Outcome measures:

The primary outcome measure was the Walking Index for Spinal Cord Injury (/20 points) and the secondary outcome was the Lower Extremity Muscle Score (/50 points).

Results:

There was no statistically significant between group differences in the Walking Index for Spinal Cord Injury [mean difference=0.3points; 95% CI (-4.8 to 5.4); p=0.748] or the Lower Extremity Muscle Score [mean difference=0.2 points; 95% CI (-3.8 to 5.1); p=0.749].

Conclusions:

Gait training with body weight-supported overground training is comparable to treadmill training for improving locomotion in people with traumatic incomplete tetraplegia.

Effects of FES-Ambulation Training on Locomotor Function and Health-Related Quality of Life in Individuals With Spinal Cord Injury

BACKGROUND

The combination of body weight-supported gait training with functional electrical stimulation (FES) may provide the optimal stimulus for improving overground walking after spinal cord injury (SCI). This potential benefit is likely due to the combination of specificity with the maximization of muscle contractions.

OBJECTIVES

To investigate the effects of 12 weeks of FES-ambulation on overground walking and health-related quality of life (HRQOL) in individuals with SCI.

METHODS

Six individuals (60.5 ± 13.2 years) with SCI (C4-L3; AIS D; 9.3 ± 12.0 years post injury), completed a thrice-weekly, 12-week FES-ambulation training program. Locomotor function was assessed via the Walking Index for Spinal Cord Injury II (WISCI II), the 6-minute walk test (6MWT), the 10-meter walk test (10MWT), and the body-weight support required during training. HRQOL was assessed via the Short Form-36, the Perceived Stress Scale, and the Center of Epidemiological Studies for Depression scale.

RESULTS

Participants showed significant improvements in the 6MWT (223.6 ± 141.5 m to 297.3 ± 164.5 m; P = .03), the required body weight support (55.3% ± 12.6% to 14.7% ± 23.2%; P = .03), and a nonsignificant trend toward an increase in walking speed during the 10MWT (0.69 ± 0.4 m/s to 0.9 ± 0.5 m/s; P = .08) following the training program. Four participants showed improvements on the WISCI II (1-4 points). Participants also showed a decrease in the Short Form-36 pain score (6.5 ± 1.2 to 5.0 ± 1.7; P = .04) and an increase in the overall mental health score (47.8 ± 12.6 to 54.2 ± 6.7; P = .04).

CONCLUSION

FES-ambulation was associated with enhanced overground walking in individuals with AIS D SCI, reduced pain, and improved mental health.

Treino locomotor com suporte parcial de peso corporal na reabilitação da lesão medular: revisão da literatura

INTRODUÇÃO: O treino locomotor com suporte de peso corporal (TLSP) é utilizado há aproximadamente 20 anos no campo da reabilitação em pacientes que sofrem de patologias neurológicas. O TLSP favorece melhoras osteomusculares, cardiovasculares e psicológicas, pois desenvolve ao máximo o potencial residual do organismo, proporcionando a reintegração na convivência familiar, profissional e social. OBJETIVO: Identificar as principais modalidades de TLSP e seus parâmetros de avaliação com a finalidade de contribuir com o estabelecimento de evidências confiáveis para as práticas reabilitativas de pessoas com lesão medular. MATERIAIS E MÉTODOS: Foram analisados artigos originais, publicados entre 2000 e 2011, que envolvessem treino de marcha após a lesão medular, com ou sem suporte parcial de peso corporal, e tecnologias na assistência do treino, como biofeedback e estimulação elétrica funcional, entre outras. RESULTADOS: A maioria dos participantes dos estudos era do sexo masculino; os níveis de lesão variavam de C3 a L3; ASIA teve pontuações de A a D; os tempos de lesão variaram entre 0,3 meses a 33 anos. Também se verificou que não há consenso em relação ao protocolo de TLSP. CONCLUSÃO: O treino locomotor com suporte de peso corporal mostra-se viável na reabilitação de pacientes que sofrem de uma patologia neurológica como a lesão medular. Independentemente do protocolo de treino utilizado, os benefícios referentes ao aumento da força muscular, manutenção ou aumento da densidade óssea, diminuição da frequência cardíaca e aumento do condicionamento físico estão presentes

Daily intermittent hypoxia enhances walking after chronic spinal cord injury: a randomized trial

Objectives:

To test the hypothesis that daily acute intermittent hypoxia (dAIH) and dAIH combined with overground walking improve walking speed and endurance in persons with chronic incomplete spinal cord injury (iSCI).

Methods:

Nineteen subjects completed the randomized, double-blind, placebo-controlled, crossover study. Participants received 15, 90-second hypoxic exposures (dAIH, fraction of inspired oxygen [Fio₂] = 0.09) or daily normoxia (dSHAM, Fio₂ = 0.21) at 60-second normoxic intervals on 5 consecutive days; dAIH was given alone or combined with 30 minutes of overground walking 1 hour later. Walking speed and endurance were quantified using 10-Meter and 6-Minute Walk Tests. The trial is registered at ClinicalTrials.gov (NCT01272349).

Results:

dAIH improved walking speed and endurance. Ten-Meter Walk time improved with dAIH vs dSHAM after 1 day (mean difference [MD] 3.8 seconds, 95% confidence interval [CI] 1.1–6.5 seconds, p = 0.006) and 2 weeks (MD 3.8 seconds, 95% CI 0.9–6.7 seconds, p = 0.010). Six-Minute Walk distance increased with combined dAIH + walking vs dSHAM + walking after 5 days (MD 94.4 m, 95% CI 17.5–171.3 m, p = 0.017) and 1-week follow-up (MD 97.0 m, 95% CI 20.1–173.9 m, p = 0.014). dAIH + walking increased walking distance more than dAIH after 1 day (MD 67.7 m, 95% CI 1.3–134.1 m, p = 0.046), 5 days (MD 107.0 m, 95% CI 40.6–173.4 m, p = 0.002), and 1-week follow-up (MD 136.0 m, 95% CI 65.3–206.6 m, p < 0.001).

Conclusions:

dAIH ± walking improved walking speed and distance in persons with chronic iSCI. The impact of dAIH is enhanced by combination with walking, demonstrating that combinatorial therapies may promote greater functional benefits in persons with iSCI.

Classification of evidence:

This study provides Class I evidence that transient hypoxia (through measured breathing treatments), along with overground walking training, improves walking speed and endurance after iSCI.

Repetitive mass practice or focused precise practice for retraining walking after incomplete spinal cord injury? A pilot randomized clinical trial

BACKGROUND

Retraining walking following spinal cord injury using visually guided tasks may be especially efficacious because it engages the motor cortex, whose input may facilitate improvements in functional walking.

OBJECTIVES

To contrast 2 methods of retraining, one emphasizing precise, visually guided walking over obstacles and on targets (Precision Training), the other emphasizing mass practice of walking on a treadmill (Endurance Training).

METHODS

A randomized, single-blind, crossover design was used. Twenty-two participants, ≥7 months postinjury, were randomly allocated to start with Precision or Endurance Training. Each phase of training was 5 times per week for 2 months, followed by a 2-month rest.

MEASURES

of walking speed, distance, skill, confidence, and depression were obtained before training, then monthly thereafter.

RESULTS

Both forms of training led to significant improvements in walking, with Endurance Training inducing bigger improvements in walking distance than Precision Training, especially for high-functioning walkers who had initial walking speeds >0.5 m/s. The largest improvements in walking speed and distance occurred in the first month of Endurance Training, with minimal changes in the second month of training. In contrast, improvements in walking skill occurred over both months during both types of training. Retention of over ground walking speed, distance, and skill was excellent for both types of training.

CONCLUSIONS

Intensive walking training in the chronic phase after spinal cord injury is effective in improving over ground walking. Visually guided tasks for training individuals with chronic spinal cord injury were not superior to mass practice on a treadmill.

Lower extremity functional electrical stimulation cycling promotes physical and functional recovery in chronic spinal cord injury

OBJECTIVE

To examine the effect of long-term lower extremity functional electrical stimulation (FES) cycling on the physical integrity and functional recovery in people with chronic spinal cord injury (SCI).

DESIGN

Retrospective cohort, mean follow-up 29.1 months, and cross-sectional evaluation.

SETTING

Washington University Spinal Cord Injury Neurorehabilitation Center, referral center.

PARTICIPANTS

Twenty-five people with chronic SCI who received FES during cycling were matched by age, gender, injury level, and severity, and duration of injury to 20 people with SCI who received range of motion and stretching.

INTERVENTION

Lower extremity FES during cycling as part of an activity-based restorative treatment regimen.

MAIN OUTCOME MEASURE

Change in neurological function: motor, sensory, and combined motor-sensory scores (CMSS) assessed by the American Spinal Injury Association Impairment scale. Response was defined as ≥ 1 point improvement.

RESULTS

FES was associated with an 80% CMSS responder rate compared to 40% in controls. An average 9.6 CMSS point loss among controls was offset by an average 20-point gain among FES subjects. Quadriceps muscle mass was on average 36% higher and intra/inter-muscular fat 44% lower, in the FES group. Hamstring and quadriceps muscle strength was 30 and 35% greater, respectively, in the FES group. Quality of life and daily function measures were significantly higher in FES group.

CONCLUSION

FES during cycling in chronic SCI may provide substantial physical integrity benefits, including enhanced neurological and functional performance, increased muscle size and force-generation potential, reduced spasticity, and improved quality of life.

Multivariate assessment of differences between a neuromuscular electrical stimulation therapy and robotic treadmill training in the rehabilitation of spinal cord injured rats

A study was conducted to evaluate and compare the effects of two different rehabilitation therapies on spinal cord injured (SCI) rats: neuromuscular electrical stimulation which is timed to robotic treadmill training (NMES+RTT) and RTT alone. Several electromyography (EMG) based variables were measured, but most did not change significantly after treatment, contrary to observations of overall qualitative stepping ability. However, when the variables are viewed in multi-dimensional space, there are visible differences between changes after NMES+RTT vs. those after RTT only. Principal component analysis (PCA) and k-means clustering were applied to the multivariate data. The data in principal component space was significantly separated, according to the Euclidean distance. PCA also provided a straightforward tool for selecting which combination of measures to compare. The measures which best separated out the differences between NMES+RTT and RTT were percentage of steps associated with bursts, burst-to-step latency, and the standard deviation of this latency, even though these measures did not always show the greatest statistical significance individually. Thus, the rehabilitative effects of NMES+RTT are not necessarily reflected in individual EMG measures, but rather in a combination of the measures representing a multi-dimensional space.

Step trajectory analysis of spinal cord injured rats trained with neuromuscular electrical stimulation coordinated with robotic treadmill training

Applying neuromuscular electrical stimulation (NMES) during treadmill training (TT) has been shown to improve functional outcomes, such as gait speed and walking distance, in spinal cord injury (SCI) patients. However, ways to improve this combined NMES+TT therapy have not been investigated. We have developed NMES system for a rodent model of SCI to investigate whether and how more precisely timing the stimulation to robotically assisted hindlimb position might achieve rehabilitation of independent stepping after SCI. In our therapy (NMES+RTT), rodent ankle flexor muscles are stimulated while the hindlimbs are robotically driven through pre-programmed trajectories during treadmill training. The objectives of the work presented here were to quantify changes in step trajectory resulting from our combined NMES+RTT therapy and compare those effects with those induced by robotic treadmill training (RTT) alone. Animals were spinally contused to model severe SCI, and either received 2 weeks of NMES+RTT followed by 2 weeks of RTT (n=6) or 2 weeks of RTT followed by 2 weeks of NMES+RTT (n=7). Changes in step trajectories after training were analyzed. According to a deviation measure we developed, the step trajectories improved after either NMES+RTT or RTT training but more closely matched the desired pre-programmed trajectories after NMES+RTT than after RTT only. The step trajectories are also more consistent, as indicated by a coefficient of variation measure, after training and more so after NMES+RTT than after RTT only. These preliminary results from our NMES+RTT vs. RTT study are consistent with the hypothesis that appropriately timing NMES with hindlimb movements during stepping is an effective therapy for restoring the ability to step after spinal cord injury.

Functional reorganization of soleus H-reflex modulation during stepping after robotic-assisted step training in people with complete and incomplete spinal cord injury

Body weight-supported (BWS) robotic-assisted step training on a motorized treadmill is utilized with the aim to improve walking ability in people after damage to the spinal cord. However, the potential for reorganization of the injured human spinal neuronal circuitry with this intervention is not known. The objectives of this study were to determine changes in the soleus H-reflex modulation pattern and activation profiles of leg muscles during stepping after BWS robotic-assisted step training in people with chronic spinal cord injury (SCI). Fourteen people who had chronic clinically complete, motor complete, and motor incomplete SCI received an average of 45 training sessions, 5 days per week, 1 h per day. The soleus H-reflex was evoked and recorded via conventional methods at similar BWS levels and treadmill speeds before and after training. After BWS robotic-assisted step training, the soleus H-reflex was depressed at late stance, stance-to-swing transition, and swing phase initiation, allowing a smooth transition from stance to swing. The soleus H-reflex remained depressed at early and mid-swing phases of the step cycle promoting a reciprocal activation of ankle flexors and extensors. The spinal reflex circuitry reorganization was, however, more complex, with the soleus H-reflex from the right leg being modulated either in a similar or in an opposite manner to that observed in the left leg at a given phase of the step cycle after training. Last, BWS robotic-assisted step training changed the amplitude and onset of muscle activity during stepping, decreased the step duration, and improved the gait speed. BWS robotic-assisted step training reorganized spinal locomotor neuronal networks promoting a functional amplitude modulation of the soleus H-reflex and thus step progression. These findings support that spinal neuronal networks of persons with clinically complete, motor complete, or motor incomplete SCI have the potential to undergo an endogenous-mediated reorganization, and improve spinal reflex function and walking function with BWS robotic-assisted step training.

Lower extremity functional electrical stimulation cycling promotes physical and functional recovery in chronic spinal cord injury

OBJECTIVE

To examine the effect of long-term lower extremity functional electrical stimulation (FES) cycling on the physical integrity and functional recovery in people with chronic spinal cord injury (SCI).

DESIGN

Retrospective cohort, mean follow-up 29.1 months, and cross-sectional evaluation.

SETTING

Washington University Spinal Cord Injury Neurorehabilitation Center, referral center.

PARTICIPANTS

Twenty-five people with chronic SCI who received FES during cycling were matched by age, gender, injury level, and severity, and duration of injury to 20 people with SCI who received range of motion and stretching.

INTERVENTION

Lower extremity FES during cycling as part of an activity-based restorative treatment regimen.

MAIN OUTCOME MEASURE

Change in neurological function: motor, sensory, and combined motor-sensory scores (CMSS) assessed by the American Spinal Injury Association Impairment scale. Response was defined as ≥ 1 point improvement.

RESULTS

FES was associated with an 80% CMSS responder rate compared to 40% in controls. An average 9.6 CMSS point loss among controls was offset by an average 20-point gain among FES subjects. Quadriceps muscle mass was on average 36% higher and intra/inter-muscular fat 44% lower, in the FES group. Hamstring and quadriceps muscle strength was 30 and 35% greater, respectively, in the FES group. Quality of life and daily function measures were significantly higher in FES group.

CONCLUSION

FES during cycling in chronic SCI may provide substantial physical integrity benefits, including enhanced neurological and functional performance, increased muscle size and force-generation potential, reduced spasticity, and improved quality of life.

Metabolic responses to 4 different body weight-supported locomotor training approaches in persons with incomplete spinal cord injury

OBJECTIVE

To describe metabolic responses accompanying 4 different locomotor training (LT) approaches.

DESIGN

Single-blind, randomized controlled trial.

SETTING

Rehabilitation research laboratory, academic medical center.

PARTICIPANTS

Individuals (N=62) with minimal walking function due to chronic motor-incomplete spinal cord injury.

INTERVENTION

Participants trained 5 days/week for 12 weeks. Groups were treadmill-based LT with manual assistance (TM), transcutaneous electrical stimulation (TS), and a driven gait orthosis (DGO) and overground (OG) LT with electrical stimulation.

MAIN OUTCOME MEASURES

Oxygen uptake (V˙o2), walking velocity and economy, and substrate utilization during subject-selected "slow," "moderate," and "maximal" walking speeds.

RESULTS

V˙o2 did not increase from pretraining to posttraining for DGO (.00 ± .18L/min, P=.923). Increases in the other groups depended on walking speed, ranging from .01 ± .18 m/s (P=.860) for TM (slow speed) to .20 ± .29 m/s (P=.017) for TS (maximal speed). All groups increased velocity but to varying degrees (DGO, .01 ± .18 Ln[m/s], P=.829; TM, .07 ± .29 Ln[m/s], P=.371; TS, .33 ± .45 Ln[m/s], P=.013; OG, .52 ±.61 Ln[m/s], P=.007). Changes in walking economy were marginal for DGO and TM (.01 ± .20 Ln[L/m], P=.926, and .00 ± .42 Ln[L/m], P=.981) but significant for TS and OG (.26 ± .33 Ln[L/m], P=.014, and .44 ± .62 Ln[L/m], P=.025). Many participants reached respiratory exchange ratios ≥ 1 at any speed, rendering it impossible to statistically discern differences in substrate utilization. However, after training, fewer participants reached this ceiling for each speed (slow: 9 vs 6, n=32; moderate: 12 vs 8, n=29; and maximal 15 vs 13, n=28).

CONCLUSIONS

DGO and TM walking training was less effective in increasing V˙o2 and velocity across participant-selected walking speeds, while TS and OG training was more effective in improving these parameters and also walking economy. Therefore, the latter 2 approaches hold greater promise for improving clinically relevant outcomes such as enhanced endurance, functionality, or in-home/community ambulation.

Modulation of ankle EMG in spinally contused rats through application of neuromuscular electrical stimulation timed to robotic treadmill training

While neuromuscular electrical stimulation (NMES) has enabled patients of neuromotor dysfunction to effectively regain some functions, analysis of neuromuscular changes underlying these functional improvements is lacking. We have developed an NMES system for a rodent model of SCI with the long term goal of creating a therapy which restores control over stepping back to the spinal circuitry. NMES was applied to the tibialis anterior (TA) and timed to the afferent feedback generated during robotic treadmill training (RTT). The effect of NMES+RTT on modifications in EMG was compared with that of RTT alone. A longitudinal study with a crossover design was conducted in which group 1 (n=7) received 2 weeks of RTT only followed by 2 weeks of NMES+RTT; group 2 (n=7) received 2 weeks of NMES+RTT followed by RTT only. On average, both types of training helped to modulate TA EMG activity over a gait cycle, resulting in EMG profiles across steps with peaks occurring just before or at the beginning of the swing phase, when ankle flexion is most needed. However, NMES+RTT resulted in concentration of EMG activation during the initial swing phase more than RTT only. In conjunction with these improvements in EMG activation presented here, a more complete analyses comparing changes after NMES+RTT vs. RTT is expected to further support the notion that NMES timed appropriately to hindlimb stepping could help to reinforce the motor learning that is induced by afferent activity generated by treadmill training.

Locomotor training for walking after spinal cord injury

BACKGROUND

A traumatic spinal cord injury (SCI) is a lesion of neural elements of the spinal cord that can result in any degree of sensory and motor deficit, autonomic or bowel dysfunction. Improvement of locomotor function is one of the primary goals for people with SCI. Locomotor training for walking is therefore used in rehabilitation after SCI and might help to improve a person's ability to walk. However, a systematic review of the evidence is required to assess the effects and acceptability of locomotor training after SCI.

OBJECTIVES

To assess the effects of locomotor training on improvement in walking for people with traumatic SCI.

SEARCH METHODS

We searched the Cochrane Injuries Group's Specialised Register (searched November 2011); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 4); MEDLINE (Ovid) (1966 to November 2011); EMBASE (Ovid) (1980 to November 2011); CINAHL (1982 to November 2011); AMED (Allied and Complementary Medicine Database) (1985 to November 2011); SPORTDiscus (1949 to November 2011); PEDro (the Physiotherapy Evidence database) (searched November 2011); COMPENDEX (engineering databases) (1972 to November 2011); and INSPEC (1969 to November 2011). We also searched the online trials databases Current Controlled Trials (www.controlled-trials.com/isrctn) and Clinical Trials (www.clinicaltrials.gov). We handsearched relevant conference proceedings, checked reference lists of relevant published papers and contacted study authors in an effort to identify published, unpublished and ongoing trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) involving people with SCI that compared locomotor training to a control of any other exercise or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial quality and extracted data. The primary outcomes were the speed of walking and walking capacity at final follow-up.

MAIN RESULTS

Five RCTs involving 309 people are included in this review. Overall, the results were inconclusive. There was no statistically significant superior effect of any locomotor training approach on walking function after SCI compared with any other kind of physical rehabilitation. The use of bodyweight supported treadmill training as locomotor training for people after SCI did not significantly increase walking velocity (0.03 m/sec with a 95% confidence interval (CI) -0.05 to 0.11; P = 0.52; I(2) = 22%) nor did it increase walking capacity (-1.3 metres (95% CI -41 to 40); P = 0.95; I(2) = 62%). However, in one study involving 74 people the group receiving robotic-assisted locomotor training had reduced walking capacity compared with people receiving any other intervention, a finding which needs further investigation. In all five studies there were no differences in adverse events or drop-outs between study groups.

AUTHORS' CONCLUSIONS

There is insufficient evidence from RCTs to conclude that any one locomotor training strategy improves walking function more than another for people with SCI. The effects especially of robotic-assisted locomotor training are not clear, therefore research in the form of large RCTs, particularly for robotic training, is needed. Specific questions about which type of locomotor training might be most effective in improving walking function for people with SCI need to be explored.

Locomotor training: as a treatment of spinal cord injury and in the progression of neurologic rehabilitation

Scientists, clinicians, administrators, individuals with spinal cord injury (SCI), and caregivers seek a common goal: to improve the outlook and general expectations of the adults and children living with neurologic injury. Important strides have already been accomplished; in fact, some have labeled the changes in neurologic rehabilitation a "paradigm shift." Not only do we recognize the potential of the damaged nervous system, but we also see that "recovery" can and should be valued and defined broadly. Quality-of-life measures and the individual's sense of accomplishment and well-being are now considered important factors. The ongoing challenge from research to clinical translation is the fine line between scientific uncertainty (ie, the tenet that nothing is ever proven) and the necessary burden of proof required by the clinical community. We review the current state of a specific SCI rehabilitation intervention (locomotor training), which has been shown to be efficacious although thoroughly debated, and summarize the findings from a multicenter collaboration, the Christopher and Dana Reeve Foundation's NeuroRecovery Network.

Basic concepts of activity-based interventions for improved recovery of motor function after spinal cord injury

Spinal cord injury (SCI) is a devastating condition that affects a large number of individuals. Historically, the recovery process after an SCI has been slow and with limited success. Recently, a number of advances have been made in the strategies used for rehabilitation, resulting in marked improved recovery, even after a complete SCI. Several rehabilitative interventions, that is, assisted motor training, spinal cord epidural stimulation, and/or administration of pharmacologic agents, alone or in combination, have produced remarkable recovery in motor function in both humans and animals. The success with each of these interventions appears to be related to the fact that the spinal cord is smart, in that it can use ensembles of sensory information to generate appropriate motor responses without input from supraspinal centers, a property commonly referred to as central pattern generation. This ability of the spinal cord reflects a level of automaticity, that is, the ability of the neural circuitry of the spinal cord to interpret complex sensory information and to make appropriate decisions to generate successful postural and locomotor tasks. Herein, we provide a brief review of some of the neurophysiologic rationale for the success of these interventions.

Lack of functional effects of neuromuscular electrical stimulation on skeletal muscle oxidative metabolism in healthy humans

A recent study has demonstrated that neuromuscular electrical stimulation (NMES) determines, in vitro, a fast-to-slow shift in the metabolic profile of muscle fibers. The aim of the present study was to evaluate if, in the same subjects, these changes would translate, in vivo, into an enhanced skeletal muscle oxidative metabolism. Seven young men were tested (cycle ergometer) during incremental exercises up to voluntary exhaustion and moderate and heavy constant-load exercises (CLE). Measurements were carried out before and after an 8-wk training program by isometric bilateral NMES (quadriceps muscles), which induced an ∼25% increase in maximal isometric force. Breath-by-breath pulmonary O2 uptake (V̇o2) and vastus lateralis oxygenation indexes (by near-infrared spectroscopy) were determined. Skeletal muscle fractional O2 extraction was estimated by near-infrared spectroscopy on the basis of changes in concentration of deoxygenated hemoglobin + myoglobin. Values obtained at exhaustion were considered “peak” values. The following functional evaluation variables were unaffected by NMES: peak V̇o2; gas exchange threshold; the V̇o2 vs. work rate relationship (O2 cost of cycling); changes in concentration of deoxygenated hemoglobin + myoglobin vs. work rate relationship (related to the matching between O2 delivery and V̇o2); peak fractional O2 extraction; V̇o2 kinetics (during moderate and heavy CLE) and the amplitude of its slow component (during heavy CLE). Thus NMES did not affect several variables of functional evaluation of skeletal muscle oxidative metabolism. Muscle hypertrophy induced by NMES could impair peripheral O2 diffusion, possibly counterbalancing, in vivo, the fast-to-slow phenotypic changes that were observed in vitro, in a previous work, in the same subjects of the present study.

Training to achieve over ground walking after spinal cord injury: a review of who, what, when, and how

OBJECTIVES

(1) To provide clinicians with the best evidence for effective retraining of walking after spinal cord injury (SCI) to achieve over ground walking. (2) To identify gaps in our knowledge to guide future research.

METHODS

Articles that addressed the retraining of walking in adults with SCI and reported outcome measures of over ground walking ability were identified through a non-systematic search of the PubMed, Scopus, and CINAHL databases. No restriction was applied to the method of training. Selected articles were appraised using the Physiotherapy Evidence Database scale. Information was synthesized to answer who best responds to what type of treatment, how that treatment should be delivered, and at what stage after injury.

RESULTS

Individuals with motor incomplete SCI (American Spinal Injury Association (ASIA) Impairment scale (AIS) C and D) are most likely to regain walking over ground. The effective methods of training all involved a substantial component of walking in the training, and if assistance was provided, partial assistance was more effective than total assistance. Walking training resulted in a change in over ground walking speed of 0.06-0.77 m/s, and 6 minute walk distance of 24-357 m. The effective training schedules ranged from 10 to 130 sessions, with a density of sessions ranging from 2 per week to 5 per week. Earlier training led to superior results both in the subacute (<6 months) and chronic phases (>6 months) after injury, but even individuals with chronic injuries of long duration can improve.

CONCLUSIONS

Frequent, early treatment for individuals with motor incomplete SCI using walking as the active ingredient whether on the treadmill or over ground, generally leads to improved walking over ground. Much work remains for the future, including better quantification of treatment intensity, better outcome measures to quantify a broader range of walking skills, and better ways to retrain individuals with more severe lesions (AIS A and B).

A system to integrate electrical stimulation with robotically controlled treadmill training to rehabilitate stepping after spinal cord injury

A functional electrical stimulation (FES) system was engineered to integrate information from a robotically controlled position during stepping in order to time stimulation to continuous gait information in a rodent model of spinal cord injury (SCI). In contrast to conventional FES systems which have a fixed timing pattern relative to gait cycle onset (i.e., toe off/heel off or paw contact/heel strike), this system allows adaptation of stimulation to a robotically controlled position. Rationale for the system design is presented along with bench-test results verifying the timing of the stimulation with respect to hindlimb position. This robotically timed FES system will enable studies investigating the capability of this FES therapy to encourage rehabilitation by way of spinal plasticity.

Plasticity of corticospinal neural control after locomotor training in human spinal cord injury

Spinal lesions substantially impair ambulation, occur generally in young and otherwise healthy individuals, and result in devastating effects on quality of life. Restoration of locomotion after damage to the spinal cord is challenging because axons of the damaged neurons do not regenerate spontaneously. Body-weight-supported treadmill training (BWSTT) is a therapeutic approach in which a person with a spinal cord injury (SCI) steps on a motorized treadmill while some body weight is removed through an upper body harness. BWSTT improves temporal gait parameters, muscle activation patterns, and clinical outcome measures in persons with SCI. These changes are likely the result of reorganization that occurs simultaneously in supraspinal and spinal cord neural circuits. This paper will focus on the cortical control of human locomotion and motor output, spinal reflex circuits, and spinal interneuronal circuits and how corticospinal control is reorganized after locomotor training in people with SCI. Based on neurophysiological studies, it is apparent that corticospinal plasticity is involved in restoration of locomotion after training. However, the neural mechanisms underlying restoration of lost voluntary motor function are not well understood and translational neuroscience research is needed so patient-orientated rehabilitation protocols to be developed.

Association between reliance on devices and people for walking and ability to walk community distances among persons with spinal cord injury

OBJECTIVE

To identify and describe the frequency of reliance on assistive devices and/or people for ambulating distances and stair climbing.

DESIGN

Survey.

SETTING

A total of 429 adults with traumatic spinal cord injury who were able to walk at least 10 m were identified through inpatient and outpatient hospital databases at a specialty hospital in the southeast United States.

OUTCOME MEASURE

Data were collected using a self-report questionnaire including items related to distances walked and devices used for ambulation.

RESULTS

Participants best able to ambulate community distances were those who were independent with ambulation and those who used one cane or crutch. Reliance on people or use of a walker was associated with walking shorter distances. Regression analysis indicated reliance on devices or people for walking predicted variation in ability to ambulate community distances after controlling for demographic and injury characteristics.

CONCLUSION

This study suggests that reliance on devices or a person for assistance is important to consider when assessing potential for achieving functional community ambulation.

Development of less invasive neuromuscular electrical stimulation model for motor therapy in rodents

BACKGROUND

Combination therapy is essential for functional repairs of the spinal cord. Rehabilitative therapy can be considered as the key for reorganizing the nervous system after spinal cord regeneration therapy. Functional electrical stimulation has been used as a neuroprosthesis in quadriplegia and can be used for providing rehabilitative therapy to tap the capability for central nervous system reorganization after spinal cord regeneration therapy.

OBJECTIVE

To develop a less invasive muscular electrical stimulation model capable of being combined with spinal cord regeneration therapy especially for motor therapy in the acute stage after spinal cord injury.

METHODS

The tibialis anterior and gastrocnemius motor points were identified in intact anesthetized adult female Fischer rats, and stimulation needle electrodes were percutaneously inserted into these points. Threshold currents for visual twitches were obtained upon stimulation using pulses of 75 or 8 kHz for 200 ms. Biphasic pulse widths of 20, 40, 80, 100, 300, and 500 µs per phase were used to determine strength-duration curves. Using these parameters and previously obtained locomotor electromyogram data, stimulations were performed on bilateral joint muscle pairs to produce reciprocal flexion/extension movements of the ankle for 15 minutes while three-dimensional joint kinematics were assessed.

RESULTS

Rhythmic muscular electrical stimulation with needle electrodes was successfully done, but decreased range of motion (ROM) over time. High-frequency and high-amplitude stimulation was also shown to be effective in alleviating decreases in ROM due to muscle fatigue.

CONCLUSIONS

This model will be useful for investigating the ability of rhythmic muscular electrical stimulation therapy to promote motor recovery, in addition to the efficacy of combining treatments with spinal cord regeneration therapy after spinal cord injuries.

Robotic resistance treadmill training improves locomotor function in human spinal cord injury: a pilot study

OBJECTIVE

To determine whether cable-driven robotic resistance treadmill training can improve locomotor function in humans with incomplete spinal cord injury (SCI).

DESIGN

Repeated assessment of the same patients with crossover design.

SETTING

Research units of rehabilitation hospitals in Chicago.

PARTICIPANTS

Patients with chronic incomplete SCI (N=10) were recruited to participate in this study.

INTERVENTIONS

Subjects were randomly assigned to 1 of 2 groups. One group received 4 weeks of assistance training followed by 4 weeks of resistance training, while the other group received 4 weeks of resistance training followed by 4 weeks of assistance training. Locomotor training was provided by using a cable-driven robotic locomotor training system, which is highly backdrivable and compliant, allowing patients the freedom to voluntarily move their legs in a natural gait pattern during body weight supported treadmill training (BWSTT), while providing controlled assistance/resistance forces to the leg during the swing phase of gait.

MAIN OUTCOME MEASURES

Primary outcome measures were evaluated for each participant before training and after 4 and 8 weeks of training. Primary measures were self-selected and fast overground walking velocity and 6-minute walking distance. Secondary measures included clinical assessments of balance, muscle tone, and strength.

RESULTS

A significant improvement in walking speed and balance in humans with SCI was observed after robotic treadmill training using the cable-driven robotic locomotor trainer. There was no significant difference in walking functional gains after resistance versus assistance training, although resistance training was more effective for higher functioning patients.

CONCLUSIONS

Cable-driven robotic resistance training may be used as an adjunct to BWSTT for improving overground walking function in humans with incomplete SCI, particularly for those patients with relatively high function.

Effect of functional electrical stimulation (FES) combined with robotically assisted treadmill training on the EMG profile

Functional electrical stimulation (FES) is used to assist spinal cord injury patients during walking. However, FES has yet to be shown to have lasting effects on the underlying neurophysiology which lead to long-term rehabilitation. A new approach to FES has been developed by which stimulation is timed to robotically controlled movements in an attempt to promote long-term rehabilitation of walking. This approach was tested in a rodent model of spinal cord injury. Rats who received this FES therapy during a 2-week training period exhibited peak EMG activity during the appropriate phase of the gait cycle; whereas, rats who received stimulation which was randomly timed with respect to their motor activity exhibited no clear pattern in their EMG profile. These results from our newly developed FES system serve as a launching point for many future studies to test and understand the long-term effect of FES on spinal cord rehabilitation.

The changing field of rehabilitation: optimizing spontaneous regeneration and functional recovery

For neurorehabilitation of patients with spinal cord injury (SCI), the traditional emphasis on social adaptation is being expanded to include strategies that promote plasticity and regeneration in the central nervous system. Such strategies are needed to optimize recovery of neurological function. For example, the known dependence of most cellular processes on physical activity has led to the novel concept that activity is important in neural repair. This hypothesis has given rise to activity-based restoration therapies (ABRT), which aim to optimize neural activity in the damaged spinal cord, particularly below the injury level. Here, we review the basic science and clinical evidence supporting the lifelong use of ABRT for recovery from spinal cord injury. We define and describe ABRT, and discuss its components, its clinical applications, its relationship to medical management of spinal cord injury, and the potential influences of medications on recovery. We also discuss the health benefits of ABRT under physiological and pathological conditions. We stress that lifelong ABRT is required to optimize return of function and to allow patients to benefit from any "cures" that will be discovered.

Comparison of training methods to improve walking in persons with chronic spinal cord injury: a randomized clinical trial

OBJECTIVE

To compare two forms of device-specific training - body-weight-supported (BWS) ambulation on a fixed track (TRK) and BWS ambulation on a treadmill (TM) - to comprehensive physical therapy (PT) for improving walking speed in persons with chronic, motor-incomplete spinal cord injury (SCI).

METHODS

Thirty-five adult subjects with a history of chronic SCI (>1 year; AIS 'C' or 'D') participated in a 13-week (1 hour/day; 3 days per week) training program. Subjects were randomized into one of the three training groups. Subjects in the two BWS groups trained without the benefit of additional input from a physical therapist or gait expert. For each training session, performance values and heart rate were monitored. Pre- and post-training maximal 10-m walking speed, balance, muscle strength, fitness, and quality of life were assessed in each subject.

RESULTS

All three training groups showed significant improvement in maximal walking speed, muscle strength, and psychological well-being. A significant improvement in balance was seen for PT and TRK groups but not for subjects in the TM group. In all groups, post-training measures of fitness, functional independence, and perceived health and vitality were unchanged.

CONCLUSIONS

Our results demonstrate that persons with chronic, motor-incomplete SCI can improve walking ability and psychological well-being following a concentrated period of ambulation therapy, regardless of training method. Improvement in walking speed was associated with improved balance and muscle strength. In spite of the fact that we withheld any formal input of a physical therapist or gait expert from subjects in the device-specific training groups, these subjects did just as well as subjects receiving comprehensive PT for improving walking speed and strength. It is likely that further modest benefits would accrue to those subjects receiving a combination of device-specific training with input from a physical therapist or gait expert to guide that training.

The relationship between prescription medication use and ability to ambulate distances after spinal cord injury

OBJECTIVE

To investigate the relationship between prescription medication use for pain and spasticity and ambulation distances while controlling for pain severity, injury severity, age, sex, and race in participants with spinal cord injury (SCI).

DESIGN

Secondary analysis of survey data.

SETTING

Specialty hospital in the Southeast United States.

PARTICIPANTS

Adults (N=407) with traumatic SCI identified through inpatient and outpatient hospital databases.

INTERVENTION

Not applicable.

MAIN OUTCOMES MEASURES

A questionnaire measured prescription medication use, ambulation distance, and other demographic data. A composite score of four 10-point scales from the Brief Pain Inventory was used to measure pain severity. Multinomial logistic regression was used to calculate the odds ratio (OR) of ambulation distance using 1000 ft or more as the reference group.

RESULTS

Persons with SCI who were heavy prescription medication users (defined as weekly or daily use for pain or spasticity) were more likely to be limited to distances less than 150 (OR, 2.82; 95% confidence interval [CI], 1.57-5.04) and 150 to 999 ft (OR, 2.52; 95% CI, 1.45-4.39).

CONCLUSION

Heavy prescription medication use for pain and spasticity was related inversely to a person's ability to achieve community ambulation distances of 1000 ft or more.

Utility of quantitative ultrasound of the calcaneus in diagnosing osteoporosis in spinal cord injury patients

OBJECTIVE

: The aim of this study was to assess the utility of quantitative ultrasound of the calcaneus in diagnosing osteoporosis in spinal cord injury patients in a Brazilian Teaching Hospital.

DESIGN

: This is a diagnostic test criterion standard comparison study. Between January 2008 and October 2009, the bone density of 15 spinal cord injury patients was assessed for analysis before beginning rehabilitation using muscle stimulation. The bone density was assessed using bone densitometry examination (DEXA) and ultrasound examination of the calcaneus (QUS). The measurements acquired using QUS and DEXA were compared between patients with spinal cord injury and a control group of ten healthy individuals.

RESULTS

: The T-score values for femoral neck using DEXA (P < 0.0022) and those using QUS of the calcaneus (P < 0.0005) differed significantly between the groups, and the means in the normal subjects were higher than those in spinal cord injury patients who would receive electrical stimulation. In spinal cord injury patients, the significant differences were found between the QUS T-score for calcaneus and the DEXA scores for the lumbar spine and femoral neck.

CONCLUSIONS

: Because of the low level of mechanical stress on the calcaneus, the results of the QUS could not be correlated with the DEXA results for diagnosing osteoporosis. Therefore, QUS seems to be not a good choice for diagnosis and follow-up.

An intensive intervention for improving gait, balance, and mobility in individuals with chronic incomplete spinal cord injury: a pilot study of activity tolerance and benefits

OBJECTIVE

To determine the tolerance to and benefits of an intensive mobility training (IMT) approach for individuals with incomplete spinal cord injury (ISCI).

DESIGN

Prospective pretest-posttest study with 6-month follow-up.

SETTING

University research laboratory.

PARTICIPANTS

A volunteer sample of individuals with ISCI (N=15; >6 mo postinjury and able to walk at least 3.05 m with or without assistance). Follow-up data were collected for 10 of the participants.

INTERVENTIONS

Participants received IMT for 3h/d for 10 weekdays, participating in activities that encouraged repetitive, task-specific training of their lower extremities in a massed practice schedule.

MAIN OUTCOME MEASURES

Amount of time spent in therapeutic activities and rest was used to assess participants' tolerance to the intervention. Treatment outcomes were assessed pretest, posttest, and 6 months after the intervention and included the Berg Balance Scale (BBS), Dynamic Gait Index (DGI), 6-minute walk test, gait speed, and Spinal Cord Injury Functional Ambulation Inventory.

RESULTS

Individuals in the higher functioning ISCI group (BBS score ≥45 and gait speed ≥0.6 m/s) spent more time in the intensive therapy on average than individuals in the lower functioning ISCI group. Effect sizes were comparable for changes in balance and mobility assessments between the lower and higher functioning groups, with the largest effect sizes observed for the DGI.

CONCLUSIONS

This dosage of IMT may be a more appropriate treatment approach for higher functioning ISCI individuals, as they were better able to tolerate the length of the session and demonstrated higher effect sizes postintervention.

Electrical stimulation of the sural cutaneous afferent nerve controls the amplitude and onset of the swing phase of locomotion in the spinal cat

Sensory feedback plays a crucial role in the control of locomotion and in the recovery of function after spinal cord injury. Investigations in reduced preparations have shown that the locomotor cycle can be modified through the activation of afferent feedback at various phases of the gait cycle. We investigated the effect of phase-dependent electrical stimulation of a cutaneous afferent nerve on the locomotor pattern of trained spinal cord-injured cats. Animals were first implanted with chronic nerve cuffs on the sural and sciatic nerves and electromyographic electrodes in different hindlimb muscles. Cats were then transected at T12 and trained daily to locomote on a treadmill. We found that electrical stimulation of the sural nerve can enhance the ongoing flexion phase, producing higher (+129%) and longer (+17.4%) swing phases of gait even at very low threshold of stimulation. Sural nerve stimulation can also terminate an ongoing extension and initiate a flexion phase. A higher prevalence of early switching to the flexion phase was observed at higher stimulation levels and if stimulation was applied in the late stance phase. All flexor muscles were activated by the stimulation. These results suggest that electrical stimulation of the sural nerve may be used to increase the magnitude of the swing phase and control the timing of its onset after spinal cord injury and locomotor training.

A portable gait assessment tool to record temporal gait parameters in SCI

BACKGROUND

The ability to objectively analyze gait in a clinical environment is challenging due to time, space and cost constraints. This study investigated the validity of a portable gait assessment tool in objectively assessing the temporal gait parameters in subjects with spinal cord injury. The portable gait assessment tool consisted of a pair of insoles instrumented with force sensing resistors that were strategically positioned over the sole of each foot.

AIM

To demonstrate the validity of the gait assessment tool by assessing the change in walking ability in incomplete spinal cord injured (ISCI) subjects, who participated in a robot-assisted gait training program.

METHODS

Eighteen subjects with either an acute or chronic ISCI participated in this study (age range 26-63 years). Each subject participated in a robot assisted gait training programme for 6 weeks. Assessments were performed using the gait assessment tool before during and after the intervention.

RESULTS

The gait assessment tool showed greater sensitivity to the change in the subject's gait, when compared to clinical assessments such as the walking index in spinal cord injury (WISCI II). Subjects with an acute ISCI showed a statistically significant (p<0.05) change in temporal gait parameters within the first 3 weeks of training.

DISCUSSION AND CONCLUSION

This study for the first time has used the gait assessment tool in an ISCI population and has demonstrated that gait parameters can be measured and changes can be quantified within a clinical environment. The statistically significant changes during the first 3 weeks of training may indicate that an effective dose of robotic training can be administered within a relatively short period in ISCI subjects during the acute phase.

Impact of a limited trial of walking training using body weight support and a treadmill on the gait characteristics of an individual with chronic, incomplete spinal cord injury

Studies showing improvement in locomotor ability for individuals with chronic spinal cord injury (SCI) use training times that may be prohibitive for clinics. The purpose of this study was to examine the impact of a limited period of training on the gait characteristics of a man with chronic, incomplete SCI. The participant was a minimally ambulatory 59-year-old man almost 3 years post C(3) central cord injury with an ASIA Impairment Scale (AIS) classification of C. The participant received 11 training sessions using body weight support and a treadmill (BWST) over a 6-week period. The Six Minute Walk Test (6 MWT), and gait characteristics measured with motion analysis were obtained pretraining and posttraining. The participant made improvements on all measured gait characteristics. The participant's walking speed and comfort level on the treadmill improved enough for him to use community resources. This participant was able to make improvements in his gait with a much shorter training time period than those reported in previous locomotor training studies. Although this man did not obtain community ambulation status, his decreased dependence on his power chair at home and his new ability to use an available treadmill allow for continued walking practice outside the clinic.

Influence of a locomotor training approach on walking speed and distance in people with chronic spinal cord injury: a randomized clinical trial

BACKGROUND

Impaired walking limits function after spinal cord injury (SCI), but training-related improvements are possible even in people with chronic motor incomplete SCI.

OBJECTIVE

The objective of this study was to compare changes in walking speed and distance associated with 4 locomotor training approaches.

DESIGN

This study was a single-blind, randomized clinical trial.

SETTING

This study was conducted in a rehabilitation research laboratory.

PARTICIPANTS

Participants were people with minimal walking function due to chronic SCI.

INTERVENTION

Participants (n=74) trained 5 days per week for 12 weeks with the following approaches: treadmill-based training with manual assistance (TM), treadmill-based training with stimulation (TS), overground training with stimulation (OG), and treadmill-based training with robotic assistance (LR).

MEASUREMENTS

Overground walking speed and distance were the primary outcome measures.

RESULTS

In participants who completed the training (n=64), there were overall effects for speed (effect size index [d]=0.33) and distance (d=0.35). For speed, there were no significant between-group differences; however, distance gains were greatest with OG. Effect sizes for speed and distance were largest with OG (d=0.43 and d=0.40, respectively). Effect sizes for speed were the same for TM and TS (d=0.28); there was no effect for LR. The effect size for distance was greater with TS (d=0.16) than with TM or LR, for which there was no effect. Ten participants who improved with training were retested at least 6 months after training; walking speed at this time was slower than that at the conclusion of training but remained faster than before training.

LIMITATIONS

It is unknown whether the training dosage and the emphasis on training speed were optimal. Robotic training that requires active participation would likely yield different results.

CONCLUSIONS

In people with chronic motor incomplete SCI, walking speed improved with both overground training and treadmill-based training; however, walking distance improved to a greater extent with overground training.

Influence of a locomotor training approach on walking speed and distance in people with chronic spinal cord injury: a randomized clinical trial

BACKGROUND

Impaired walking limits function after spinal cord injury (SCI), but training-related improvements are possible even in people with chronic motor incomplete SCI.

OBJECTIVE

The objective of this study was to compare changes in walking speed and distance associated with 4 locomotor training approaches.

DESIGN

This study was a single-blind, randomized clinical trial.

SETTING

This study was conducted in a rehabilitation research laboratory.

PARTICIPANTS

Participants were people with minimal walking function due to chronic SCI.

INTERVENTION

Participants (n=74) trained 5 days per week for 12 weeks with the following approaches: treadmill-based training with manual assistance (TM), treadmill-based training with stimulation (TS), overground training with stimulation (OG), and treadmill-based training with robotic assistance (LR).

MEASUREMENTS

Overground walking speed and distance were the primary outcome measures.

RESULTS

In participants who completed the training (n=64), there were overall effects for speed (effect size index [d]=0.33) and distance (d=0.35). For speed, there were no significant between-group differences; however, distance gains were greatest with OG. Effect sizes for speed and distance were largest with OG (d=0.43 and d=0.40, respectively). Effect sizes for speed were the same for TM and TS (d=0.28); there was no effect for LR. The effect size for distance was greater with TS (d=0.16) than with TM or LR, for which there was no effect. Ten participants who improved with training were retested at least 6 months after training; walking speed at this time was slower than that at the conclusion of training but remained faster than before training.

LIMITATIONS

It is unknown whether the training dosage and the emphasis on training speed were optimal. Robotic training that requires active participation would likely yield different results.

CONCLUSIONS

In people with chronic motor incomplete SCI, walking speed improved with both overground training and treadmill-based training; however, walking distance improved to a greater extent with overground training.

Effects of robot-driven gait orthosis treadmill training on the autonomic response in rehabilitation-responsive stroke and cervical spondylotic myelopathy patients

Body weight supported treadmill training (BWSTT) assisted with a robotic-driven gait orthosis is utilized in rehabilitation of individuals with lost motor skills. A typical rehabilitation session included: sitting, standing, suspension, robotic-assisted walking at 1.5 and 2.5km/h, respectively with 50% body weight support and recovery. While the effects of robotic-assisted BWSTT on motor performances were deeply studied, the influences on the cardiovascular control are still unknown. The aim of the study was to evaluate in stroke (ST) and cervical spondylotic myelopathy (CSM) patients: (1) the autonomic response during a traditional robotic-assisted BWSTT session of motor rehabilitation; (2) the effects of 30 daily sessions of BWSTT on cardiovascular regulation. The autonomic response was assessed through symbolic analysis of short-term heart rate variability in 11 pathologic subjects (5 ST and 6 CSM patients) whose motor skills were improved as a result of the rehabilitation therapy. Results showed variable individual responses to the rehabilitation session in ST patients at the beginning of the therapy. At the end of the rehabilitation process, the responses of ST patients were less variable and more similar to those previously observed in healthy subjects. CSM patients exhibited an exaggerated vagal response to the fastest walking phase during the first rehabilitative session. This abnormal response was limited after the last rehabilitative session. We conclude that robotic-assisted BWSTT is helpful in restoring cardiovascular control in rehabilitation-responsive ST patients and limiting vagal responses in rehabilitation-responsive CSM patients.

Repetetive hindlimb movement using intermittent adaptive neuromuscular electrical stimulation in an incomplete spinal cord injury rodent model

The long-term objective of this work is to understand the mechanisms by which electrical stimulation based movement therapies may harness neural plasticity to accelerate and enhance sensorimotor recovery after incomplete spinal cord injury (iSCI). An adaptive neuromuscular electrical stimulation (aNMES) paradigm was implemented in adult Long Evans rats with thoracic contusion injury (T8 vertebral level, 155+/-2 Kdyne). In lengthy sessions with lightly anesthetized animals, hip flexor and extensor muscles were stimulated using an aNMES control system in order to generate desired hip movements. The aNMES control system, which used a pattern generator/pattern shaper structure, adjusted pulse amplitude to modulate muscle force in order to control hip movement. An intermittent stimulation paradigm was used (5-cycles/set; 20-second rest between sets; 100 sets). In each cycle, hip rotation caused the foot plantar surface to contact a stationary brush for appropriately timed cutaneous input. Sessions were repeated over several days while the animals recovered from injury. Results indicated that aNMES automatically and reliably tracked the desired hip trajectory with low error and maintained range of motion with only gradual increase in stimulation during the long sessions. Intermittent aNMES thus accounted for the numerous factors that can influence the response to NMES: electrode stability, excitability of spinal neural circuitry, non-linear muscle recruitment, fatigue, spinal reflexes due to cutaneous input, and the endogenous recovery of the animals. This novel aNMES application in the iSCI rodent model can thus be used in chronic stimulation studies to investigate the mechanisms of neuroplasticity targeted by NMES-based repetitive movement therapy.

Patterns of muscle coordination vary with stride frequency during weight assisted treadmill walking

Partial body weight-supported treadmill training is an approach for gait rehabilitation. Variables such as stepping frequency and the amount of body weight support are key parameters manipulated during training. The purpose of this study was to quantify the extent to which body weight support and stride frequency contribute and interact to produce the coordination patterns of the leg muscles. Principal components analysis was used to provide insight into the interaction effects of these factors on electromyographical (EMG) activity during treadmill locomotion. Eight healthy subjects walked on a treadmill at 15 different combinations of weight support (0%, 20%, 40%, 60%, 100%), and stride frequency (0.40, 0.49, 0.57 Hz). Treadmill walking was performed with the Lokomat robotic gait orthosis to constrain leg kinematics. Surface EMG data were collected from several lower limb muscles. Results indicate that much of the variance in EMG activity during treadmill locomotion can be attributed to the mechanics of the locomotor task imposed by the level of body weight support and stride frequency. We also showed that body weight support and stride frequency interact in different ways to affect muscle coordination patterns. EMG coordination patterns are similar between conditions of high levels of body weight support and faster stride frequencies vs. lower levels of body weight support and slower stride frequency. Our data suggest that the interaction of body weight support and stride frequency should be taken into consideration for optimizing motor output during locomotor training.

Treadmill-based locomotor training with leg weights to enhance functional ambulation in people with chronic stroke: a pilot study

BACKGROUND AND PURPOSE

Novel locomotor training strategies for individuals with disorders of the central nervous system have been associated with improved locomotor function. The purpose of this study was to investigate the effects of treadmill-based locomotor training combined with leg weights on functional ambulation in individuals with chronic stroke. We assessed functional ambulation and muscle activity in ambulatory individuals with chronic stroke.

METHODS

We used a pre/posttest design. Six individuals with chronic stroke who were community ambulators were recruited. Participants underwent a 30-minute treadmill-based locomotor training sessions three times per week for four to 12 weeks. The training program involved treadmill walking for 30 minutes with partial body weight support as needed. Leg weights, equivalent to 5% of body weight, were affixed around the paretic leg. Outcome measures consisted of the 10-m walk test, the modified Emory Functional Ambulation Profile, and temporal gait parameters.

RESULTS

Improvements were observed in functional ambulation measures, particularly the stairs subscore of the modified Emory Functional Ambulation Profile. Participants also exhibited an increase in the proportion of time the paretic leg spent in swing. No significant improvements were observed in the 10-m walk test.

CONCLUSIONS

This pilot study demonstrates that the combination of leg weights and treadmill training is a feasible approach, that is well tolerated by participants. This approach may have the potential to improve some aspects of functional ambulation and the performance of activities requiring hip and knee flexion.

Long-term therapeutic and orthotic effects of a foot drop stimulator on walking performance in progressive and nonprogressive neurological disorders

BACKGROUND

Stimulators applying functional electrical stimulation (FES) to the common peroneal nerve improve walking with a foot drop, which occurs in several disorders.

OBJECTIVE

To compare the orthotic and therapeutic effects of a foot drop stimulator on walking performance of subjects with chronic nonprogressive (eg, stroke) and progressive (eg, multiple sclerosis) disorders.

METHODS

Subjects with nonprogressive (41) and progressive (32) conditions used a foot drop stimulator for 3 to 12 months while walking in the community. Walking speed was measured with a 10-m test and a 4-minute figure-8 test; physiological cost index (PCI) and device usage were also measured. The subjects were tested with FES on and off (orthotic effect) before and after (therapeutic effect) stimulator use.

RESULTS

After 3 months of FES use, the nonprogressive and progressive groups had a similar, significant orthotic effect (5.0% and 5.7%, respectively, P < .003; percentage change in mean values) and therapeutic effect with FES off (17.8% and 9.1%, respectively, P < .005) on figure-8 walking speed. Overall, PCI showed a decreasing trend (P = .031). The therapeutic effect on figure-8 speed diverged later between both groups to 28.0% (P < .001) and 7.9% at 11 months. The combined therapeutic plus orthotic effect on figure-8 speed at 11 months was, respectively, 37.8% (P < .001) and 13.1% (P = .012); PCI decreased 18.2% (P = .038) and 6.5%, respectively.

CONCLUSIONS

Subjects with progressive and nonprogressive disorders had an orthotic benefit from FES up to 11 months. The therapeutic effect increased for 11 months in nonprogressive disorders but only for 3 months in progressive disorders. The combined effect remained significant and clinically relevant.