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Journal ArticleDOI

Isometric hip and knee torque measurements as an outcome measure in robot assisted gait training

01 Jan 2014-NeuroRehabilitation (IOS Press)-Vol. 34, Iss: 2, pp 287-295

TL;DR: The peak torque recorded during isometric contractions provided an objective outcome measure to record changes in muscle strength following RAGT.
Abstract: BACKGROUND: Strength changes in lower limb muscles following robot assisted gait training (RAGT) in subjects with incomplete spinal cord injury (ISCI) has not been quantified using objective outcome measures. OBJECTIVE: To record changes in the force generating capacity of lower limb muscles (recorded as peak voluntary isometric torque at the knee and hip), before, during and after RAGT in both acute and subacute/chronic ISCI subjects using a repeated measures study design. METHODS: Eighteen subjects with ISCI participated in this study (Age range: 26–63 years mean age = 49.3 ± 11 years). Each subject participated in the study for a total period of eight weeks, including 6 weeks of RAGT using the Lokomat system (Hocoma AG, Switzerland). Peak torques were recorded in hip flexors, extensors, knee flexors and extensors using torque sensors that are incorporated within the Lokomat. RESULTS: All the tested lower limb muscle groups showed statistically significant (p < 0.001) increases in peak torques in the acute subjects. Comparison between the change in peak torque generated by a muscle and its motor score over time showed a non-linear relationship. CONCLUSIONS: The peak torque recorded during isometric contractions provided an objective outcome measure to record changes in muscle strength following RAGT.
Topics: Isometric exercise (54%), Gait training (53%)

Summary (3 min read)

Introduction

  • The primary sensory and motor consequences of spinal cord injury (SCI) are well known, and vary according to the level and extent of lesion.
  • This degree of muscle atrophy and the related loss of force generating capacity can contribute to functional impairment and can compromise progression of rehabilitation in SCI subjects.
  • In recent years the use of robotic assistance during BWSTT has emerged as an alternative to therapist assisted(Adams et al., 2006; Hicks et al., 2005) or FES assisted BWSTT(Postans et al., 2004) and may provide a more resource efficient method of delivering intensive and progressive gait training (Hornby, Zemon, & Campbell, 2005).
  • 2005), and chronic ISCI subjects (Wirz et al., 2005) there have been no studies documenting the associated changes in the force generating capacity of the lower limb muscles, in subjects as they progress through RAGT using BWSTT Strength changes in lower limb muscles following locomotor training have been previously documented in ISCI subjects using objective outcome measures such as peak torque recorded using a Biodex dynamometer.
  • Recently it has been shown that the peak torques, recorded using the torque sensors integrated within the DGO exoskeleton, provides data with good inter and intra-rater reliability in both healthy subjects and subjects with neuromuscular disorder.

Methodology

  • Eighteen subjects with ISCI participated in this study (Age range: 26-63 years mean age = 49.3 + 11 years) of which five were classified as sub acute/chronic subjects (> 6 months from time of injury) and thirteen were classified as acute subjects (<6 months from the time of injury).
  • Subjects were recruited if they were Acute or Chronic ISCI subjects graded as AIS classification C/D.(Marino et al., 2003) Between the ages of 18-65 years.
  • Subjects were not recruited if they had Complications requiring immobilization such as fractures and pressure sores.
  • Osteoporosis or contractures limiting range of motion.
  • Ethics approval was obtained from the National Health Service (NHS) regional ethics committee and subjects were recruited from the Queen Elizabeth National Spinal Injuries Unit, Glasgow.

Insert Table 1 here.

  • Informed and signed consent was obtained from all subjects prior to the start of the study.
  • A repeated measures study design was used.
  • When RAGT began, subjects walked on the Lokomat at a speed of 1-1.2 km/h with body weight support between 80-70% of their body weight.
  • This protocol was adopted in order to prevent any effects including muscle fatigue that subjects may experience following training, which may influence the subject’s ability to perform a peak isometric contraction.
  • If the Friedman’s test indicated that there were significant differences in the generated peak torques over the six weeks of training, a Wilcoxon signed rank test was used to identify the between week differences in the generated peak torque.

Results

  • Locomotor function (measured using WISCI II) following RAGT showed a greater increase in acute subjects compared to subacute/chronic subjects .

Insert Figure 1 here.

  • The peak torque generated as a result of isometric contraction of the muscle was successfully recorded in the hip flexors and extensors and knee flexors and extensors in all subjects.
  • Examples of the peak torques recorded in two acute subjects (P15 and P10) are presented in Figures 2a and 2b respectively.
  • Both subjects (P15 and P10) were classified as AIS D on the ASIA scale.
  • Subject P15 was unable able to walk prior to the RAGT but following six weeks of Lokomat training the subject was able to walk with the assistance of single elbow crutch and without any braces, hence progressing from a score of 0 to a score of 19 on the WISCI II scale.
  • In contrast, P10 who remained non-ambulant showed little or no change in the peak torque generated by the lower limb muscles tested over the six weeks of RAGT.

Insert Figure 2 (2a& 2b) here.

  • The normalized values of the peak torques generated in the hip flexor and extensors and knee flexors and extensors were analyzed separately for acute and subacute/chronic subjects.
  • In the subacute/chronic subjects the pooled data showed no significant change in the peak torque generated throughout the six weeks of RAGT .
  • This contrasts with data from acute subjects who show a gradual increase in their peak torque over the six weeks of RAGT .

Insert Figures 3(3a, 3b) & 4(4a,4b) here.

  • Friedman’s test performed on the pooled data from subacute/chronic subjects showed that the change in peak torque over the 6 weeks were not significant in all four muscle groups (hip flexor p=0.656, hip extensor p=0.608, knee flexor p=0.192 and knee extensor p=0.156).
  • Friedman’s test performed on the pooled data from acute subjects showed that the change in peak torque over the 6 weeks in acute subjects were highly significant in all four muscle groups (p<0.001 in all four muscle groups).
  • Therefore a Wilcoxon signed rank test was used to compare the peak torques recorded between the training weeks in acute subjects.
  • The results of these tests along with their p value are presented in Table 2.

Insert Table 2 here.

  • An increase in the lower limb motor score corresponded to an increase in the peak torque generated by the muscles that were tested.
  • However this correlation between the motor score and peak torque was not a linear relationship .
  • When the subject had the ability to perform full ROM against gravity in both lower limbs i.e. having a lower limb motor score >6, the between subject variability of the peak torque measure increased.
  • This observation was valid for both acute and sub-acute/chronic subjects who had participated in this study.
  • In addition, subacute/chronic subjects had higher lower limb motor score in both hip and knee joints compared to the acute subjects.

Discussion

  • This study has succeeded in objectively recording changes in muscle strength in both acute and subacute/chronic subjects with ISCI during their participation in a 6 week intensive Lokomat RAGT programme.
  • An increase in the recorded peak torque in the lower limb muscles was generally accompanied by a better ambulatory function in acute subjects as illustrated in the example shown in Figure 2a.
  • From the evidence presented in this study, it is clear that for those subjects that respond to the RAGT that significant gains in the force generating capacity of the lower limb muscles can be observed by the third week of training (Table 2) in acute ISCI subjects.
  • This is likely to be due to the fact that these subacute/chronic subjects were ambulant; therefore a better ambulatory capacity following ISCI seems to stabilize muscle strength.
  • At these grades the lack of precision in the manual muscle test scoring system makes it difficult to account for improvement in the force generating capacity of the muscle.

Conclusion

  • This study has recorded in ISCI subjects patterns of change in isometric peak torque in lower limb muscles over a 6 week programme of RAGT.
  • Peak torque seems to increase most in those subjects who achieve the greatest change in locomotor function at the end of the 6 week training period.
  • The measurement of isometric peak torque and its use as an outcome measure provides a more objective method for longitudinal monitoring of the force generating capacity of the muscle in subjects post injury, compared to the use of manual muscle testing.
  • The differential effects of Lokomat training on muscle strength seen in acute verses subacute/chronic ISCI subjects also merits further investigation using a larger sample of subjects.
  • Similarly, regular monitoring for change in the force generating capacity of the lower limb muscles can provide a useful yet simple method for personalizing the rehabilitation programme and in identifying responding subjects.

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1
Isometric Hip and Knee Torque measurements as an outcome
measure in Robot Assisted Gait Training
Sujay S Galen
1,2,3
Celia J Clarke
1,2
, Alan N Mclean
2
, David B Allan
2
, Bernard A Conway
1,2
1 Bioengineering Unit, University of Strathclyde, Glasgow, UK.
2 Scottish Centre for Innovation in Spinal Cord Injury (SCISCI), Queen Elizabeth National Spinal
Injuries Unit, Southern General Hospital, Glasgow, UK.
3 Physical Therapy Program, Eugene Applebaum College of Pharmacy and Health Care Sciences,
Wayne State University, Detroit, MI, USA.
*Correspondence to first author at
Physical Therapy Program
Wayne State University
259 Mack Avenue
Detroit, MI 48201.
USA.
Tel: +1 (313) 577 5531
Fax: +1 (313) 577 8685
e-mail: sujay.galen@wayne.edu
Keywords: Incomplete spinal cord injury, Lokomat, Peak torque, Dynamometry, Muscle
strength, Body weight supported treadmill training.

2
Abstract
Background: Strength changes in lower limb muscles following robot assisted gait training
(RAGT) in subjects with incomplete spinal cord injury (ISCI) has not been quantified using
objective outcome measures.
Objective: To record changes in the force generating capacity of lower limb muscles
(recorded as peak voluntary isometric torque at the knee and hip), before, during and after
RAGT in both acute and subacute/chronic ISCI subjects using a repeated measures study
design.
Methods: Eighteen subjects with ISCI participated in this study (Age range: 26-63 years
mean age = 49.3 + 11 years). Each subject participated in the study for a total period of
eight weeks, including 6 weeks of RAGT using the Lokomat system (Hocoma AG,
Switzerland). Peak torques were recorded in hip flexors, extensors, knee flexors and
extensors using torque sensors that are incorporated within the Lokomat.
Results: All the tested lower limb muscle groups showed statistically significant (p<0.001)
increases in peak torques in the acute subjects. Comparison between the change in peak
torque generated by a muscle and its motor score over time showed a non-linear relationship.
Conclusions: The peak torque recorded during isometric contractions provided an objective
outcome measure to record changes in muscle strength following RAGT.

3
Introduction
The primary sensory and motor consequences of spinal cord injury (SCI) are well known, and
vary according to the level and extent of lesion. .However, with paralysis comes a secondary
complication of muscle atrophy. Following injury, the onset of muscle atrophy can be rapid
and is evident soon after injury(Dudley-Javoroski & Shields, 2008). The loss of muscle cross
sectional area in SCI subjects has been reported to be between 18 and 46% on average when
compared with neurologically intact individuals (Giangregorio & McCartney, 2006). This
degree of muscle atrophy and the related loss of force generating capacity can contribute to
functional impairment and can compromise progression of rehabilitation in SCI subjects.
Accordingly, methods for early mobilization may mitigate against atrophy by either reversing
or reducing the rate of muscle loss. In ISCI subjects receiving intensive gait rehabilitation,
this is likely to be a factor that facilitates the functional recovery of gait (Dietz, Colombo,
Jensen, & Baumgartner, 1995).
Bodyweight supported treadmill training (BWSTT) has been shown to improve walking
ability (Nymark et al., 1998; Postans, Hasler, Granat, & Maxwell, 2004) in ISCI subjects and
is increasingly being adopted within physical therapy programs (Hicks & Martin Ginis,
2008). For acute subjects BWSTT also serves as a method for early lower limb mobilization
and exercise.
In recent years the use of robotic assistance during BWSTT has emerged as an alternative to
therapist assisted(Adams et al., 2006; Hicks et al., 2005) or FES assisted BWSTT(Postans et
al., 2004) and may provide a more resource efficient method of delivering intensive and
progressive gait training (Hornby, Zemon, & Campbell, 2005). The Lokomat® (Hocoma
AG, Switzerland) is a robotic driven gait orthosis (DGO) that provides robot assisted gait
training (RAGT) using BWSTT. Although preliminary studies have shown that Lokomat

4
training improves gait in both acute (Hornby et al., 2005), and chronic ISCI subjects (Wirz et
al., 2005) there have been no studies documenting the associated changes in the force
generating capacity of the lower limb muscles, in subjects as they progress through RAGT
using BWSTT
Strength changes in lower limb muscles following locomotor training have been previously
documented in ISCI subjects using objective outcome measures such as peak torque recorded
using a Biodex dynamometer. (Jayaraman et al., 2008) Given that the Lokomat system is
equipped with integrated torque sensors within the DGO exoskeleton, the device has the
capability to be used as a dynamometer in its own right. Recently it has been shown that the
peak torques, recorded using the torque sensors integrated within the DGO exoskeleton,
provides data with good inter and intra-rater reliability in both healthy subjects and subjects
with neuromuscular disorder.(Bolliger, Banz, Dietz, & Lunenburger, 2008) This inbuilt
capability provides the opportunity for monitoring the peak torques generated around hip and
knee during voluntary isometric exertions, and has a potential use as a clinical measure to
monitor the subject’s progress through the rehabilitation programme (Bolliger et al., 2008;
Lunenburger, Colombo, Riener, & Dietz, 2004). In this study we set out to record the change
in voluntary force generating capacity in the hip and knee flexors and extensor muscles,
before, during and at the end of RAGT in both acute and subacute/chronic ISCI subjects. The
quantitative force data is then compared with the equivalent manual muscle scores acquired
from subjects as part of the standard neurological classification of spinal cord injury. (Marino
et al., 2003)
Methodology
Eighteen subjects with ISCI participated in this study (Age range: 26-63 years mean age =
49.3 + 11 years) of which five were classified as sub acute/chronic subjects (> 6 months from

5
time of injury) and thirteen were classified as acute subjects (<6 months from the time of
injury). Subjects were recruited if they were
Acute or Chronic ISCI subjects graded as AIS classification C/D.(Marino et al., 2003)
Between the ages of 18-65 years.
Assessed as medically stable by an (independent) physician.
Subjects were not recruited if they had
Complications requiring immobilization such as fractures and pressure sores.
Osteoporosis or contractures limiting range of motion.
A bodyweight of over 130 kg or thigh length over 47 cms (Lokomat restrictions).
Ethics approval was obtained from the National Health Service (NHS) regional ethics
committee and subjects were recruited from the Queen Elizabeth National Spinal Injuries
Unit, Glasgow. The details of the subjects who participated in the study are provided in
Table1.
Insert Table 1 here.
Informed and signed consent was obtained from all subjects prior to the start of the study.
Each subject participated in the study for a total period of 8 weeks. A repeated measures
study design was used. A battery of neuro-physiological and functional outcome measures
were used to record the subject’s baseline and final measures during week1 and week8 of the
study respectively. RAGT was provided using the Lokomat for an hour each week day
(Monday to Friday) from Week 2 to Week 7 (a total of 6 weeks) for each subject. For more
details on the outcome measures used in this study , refer to Ellaway et al 2010. (Ellaway et

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TL;DR: There is no consistent benefit from rehabilitation using an exoskeleton versus a variety of conventional methods in patients with chronic spinal cord injury and later-generation exoskeletons are needed.
Abstract: Study Design Systematic review. Clinical Questions (1) When used as an assistive device, do wearable exoskeletons improve lower extremity function or gait compared with knee-ankle-foot orthoses (KAFOs) in patients with complete or incomplete spinal cord injury? (2) When used as a rehabilitation device, do wearable exoskeletons improve lower extremity function or gait compared with other rehabilitation strategies in patients with complete or incomplete spinal cord injury? (3) When used as an assistive or rehabilitation device, are wearable exoskeletons safe compared with KAFO for assistance or other rehabilitation strategies for rehabilitation in patients with complete or incomplete spinal cord injury? Methods PubMed, Cochrane, and Embase databases and reference lists of key articles were searched from database inception to May 2, 2016, to identify studies evaluating the effectiveness of wearable exoskeletons used as assistive or rehabilitative devices in patients with incomplete or complete spinal cord injury. Results No comparison studies were found evaluating exoskeletons as an assistive device. Nine comparison studies (11 publications) evaluated the use of exoskeletons as a rehabilitative device. The 10-meter walk test velocity and Spinal Cord Independence Measure scores showed no difference in change from baseline among patients undergoing exoskeleton training compared with various comparator therapies. The remaining primary outcome measures of 6-minute walk test distance and Walking Index for Spinal Cord Injury I and II and Functional Independence Measure–Locomotor scores showed mixed results, with some studies indicating no difference in change from baseline between exoskeleton training and comparator therapies, some indicating benefit of exoskeleton over comparator therapies, and some indicating benefit of comparator therapies over exoskeleton. Conclusion There is no data to compare locomotion assistance with exoskeleton versus conventional KAFOs. There is no consistent benefit from rehabilitation using an exoskeleton versus a variety of conventional methods in patients with chronic spinal cord injury. Trials comparing later-generation exoskeletons are needed.

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Abstract: Neuromuscular impairment and reduced musculoskeletal integrity are hallmarks of spinal cord injury (SCI) that hinder locomotor recovery. These impairments are precipitated by the neurological insult and resulting disuse, which has stimulated interest in activity-based physical rehabilitation therapies (ABTs) that promote neuromuscular plasticity after SCI. However, ABT efficacy declines as SCI severity increases. Additionally, many men with SCI exhibit low testosterone, which may exacerbate neuromusculoskeletal impairment. Incorporating testosterone adjuvant to ABTs may improve musculoskeletal recovery and neuroplasticity because androgens attenuate muscle loss and the slow-to-fast muscle fiber-type transition after SCI, in a manner independent from mechanical strain, and promote motoneuron survival. These neuromusculoskeletal benefits are promising, although testosterone alone produces only limited functional improvement in rodent SCI models. In this review, we discuss the (1) molecular deficits underlying muscle loss after SCI; (2) independent influences of testosterone and locomotor training on neuromuscular function and musculoskeletal integrity post-SCI; (3) hormonal and molecular mechanisms underlying the therapeutic efficacy of these strategies; and (4) evidence supporting a multimodal strategy involving ABT with adjuvant testosterone, as a potential means to promote more comprehensive neuromusculoskeletal recovery than either strategy alone.

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Cites background from "Isometric hip and knee torque measu..."

  • ..., 2014 [228] Robotic-assisted BWSTT 5 days/wk, 6 wk ASIA C&D 14 M/4 F Percent peak torque increased 68% for hip flexion, 54% for hip extension, 93% for knee flexion and 71% for knee extension....

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TL;DR: How a link between conventional scales and robotic/sensor-based assessments could be established and how this could result in more objective, clinically accepted assessment scales are discussed are discussed.
Abstract: Neurological disorders such as stroke, multiple sclerosis, traumatic brain injury, cerebral palsy, or spinal cord injury result in partial or complete sensorimotor impairments in the affected limbs. To provide an optimal rehabilitation program, a detailed assessment of the nature and degree of the sensorimotor deficits, as well as their temporal evolution, is crucial. Valid, reliable, and standardized assessments are essential to define the rehabilitation setting, and adapt it over the course of a therapy. Many clinical assessments suffer from limitations such as poor validity, low reliability, and low sensitivity and are often time consuming to administer, which greatly limits their systematic use in daily clinical routine. Rehabilitation robotics and sensor technologies are promising approaches that can provide objective, sensitive, and reliable measurements, which could help overcome the common limitations of conventional clinical assessments. This chapter focuses on the novel possibilities robotic devices and sensor technologies offer in the field of neurorehabilitation. Different strategies to evaluate sensorimotor impairments using robotic platforms, as well as wearable sensor technologies, are presented. We discuss how a link between conventional scales and robotic/sensor-based assessments could be established and how this could result in more objective, clinically accepted assessment scales. Such scales have the potential to directly influence the way therapy is provided and to generate new insights into long-term recovery and transfer of therapy into performance in the home environment.

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TL;DR: The reliability of the EMGFT for cycle ergometry is a reliable measure for assessing muscular fatigue and was in the “excellent” category.
Abstract: INTRODUCTION The purpose of this study was to determine the intersession reliability of the electromyographic fatigue threshold (EMGFT ) for cycle ergometry. METHODS On separate occasions, 10 healthy, college-aged men performed an incremental test to voluntary exhaustion on a cycle ergometer. The EMG amplitude vs. time relationships for each power output from the quadriceps femoris muscles were analyzed using linear regression. EMGFT was defined operationally as the average of the highest power output that resulted in a non-significant slope coefficient (P > 0.05) and the lowest power output that resulted in a significant (P < 0.05) positive slope coefficient. The EMGFT values for trials 1 and 2 were used to calculate the intraclass correlation coefficient (ICC). RESULTS Overall, the reliability of the EMGFT (ICC2,1 = 0.85; 95% confidence interval 0.49-0.96) was in the "excellent" category. CONCLUSIONS The EMGFT for cycle ergometry is a reliable measure for assessing muscular fatigue.

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  • ...The amplitude (mVrms) value for the EMG signal was calculated as the average of the completed bursts from 10-second epochs during the last 10seconds of each power output until participants reached voluntary fatigue.(22) The EMG signals were bandpass filtered (fourth-order Butterworth) at 10–500 HZ....

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TL;DR: The log‐transformed EMG amplitude‐power output relationship is a reliable index for measuring motor unit activation in healthy college‐aged men.
Abstract: Introduction: The purpose of this investigation was to determine the reproducibility of the log-transformed model for electromyography (EMG) amplitude during incremental single-leg knee-extensor exercise. Methods: Eight healthy college-aged men performed 3 incremental tests on separate occasions on a knee-extensor ergometer. EMG amplitude was analyzed for each participant on each occasion for the rectus femoris and vastus medialis muscles at 4 different exercise power outputs (30%, 50%, 70%, and 90%) corresponding to each participant's maximal power output. Intraclass correlation coefficients (ICC) were determined for the slope and y-intercept terms derived from the log-transformed EMG amplitude-power output relationship for each muscle. Results: The ICC values for the rectus femoris (slope = 0.779; y-intercept = 0.787) and vastus medialis (slope = 0.756; y-intercept = 0.763) muscles were high. Conclusions: The log-transformed EMG amplitude-power output relationship is a reliable index for measuring motor unit activation. Muscle Nerve 52:428–434, 2015

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  • ...The amplitude (microvolts root mean square, mVrms) value for the EMG signal was calculated as the average of the completed kick thrusts from 10s epochs during the last 10 s of each power output until the participants reached voluntary fatigue.(21) The EMG amplitude from the MVIC was calculated for a 2-s time period corresponding to seconds 2–4 of the 6-s isometric muscle contraction....

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References
More filters

Journal ArticleDOI
Abstract: (2003). International Standards For Neurological Classification Of Spinal Cord Injury. The Journal of Spinal Cord Medicine: Vol. 26, No. sup1, pp. S50-S56.

1,764 citations


"Isometric hip and knee torque measu..." refers background or methods in this paper

  • ...(Marino et al., 2003)...

    [...]

  • ... Acute or Chronic ISCI subjects graded as AIS classification C/D.(Marino et al., 2003)  Between the ages of 18-65 years....

    [...]

  • ...Subjects were recruited if they were Acute or Chronic ISCI subjects graded as AIS classification C/D.(Marino et al., 2003) Between the ages of 18-65 years....

    [...]


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TL;DR: In this study intrathecal application of clonidine drastically reduced, while epinephrine enhanced locomotor muscle electromyographic activity caused the induction of complex bilateral leg muscle activation combined with coordinated stepping movements in patients with complete paraplegia.
Abstract: The induction of complex bilateral leg muscle activation combined with coordinated stepping movements is demonstrated in patients with complete paraplegia. This was achieved by partially unloading patients who were on a moving treadmill. In comparison to healthy subjects, the paraplegic patients displayed a less dynamic mode of muscle activation. In all other respects leg muscle electromyographic activity was modulated in a similar manner to that in healthy subjects. However, the level of electromyographic activity in the gastrocnemius (the main antigravity muscle during gait) was considerably lower in the patients. During the course of a daily locomotor training program, the amplitude of gastrocnemius electromyographic activity increased significantly during the stance phase, while inappropriate tibialis anterior activation decreased. Incompletely paraplegic patients benefited from the training with respect to performance of unsupported stepping movements on solid ground. In about half of completely paraplegic patients with low muscle tone, no beneficial effect of the training was seen. This may be due to an inhibitory effect on spinal neuronal activity by drugs patients were taking (e.g., prazosin, clonidine, cannabinoids). In this study intrathecal application of clonidine drastically reduced, while epinephrine enhanced locomotor muscle electromyographic activity. The results of this study promise to be significant in the treatment of paraplegic patients.

514 citations


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Markus Wirz1, David H. Zemon2, R Rupp, Anke Scheel  +5 moreInstitutions (4)
TL;DR: Intensive locomotor training on a treadmill with the assistance of a DGO resulted in significant improvements in the subjects' gait velocity, endurance, and performance of functional tasks.
Abstract: Wirz M, Zemon DH, Rupp R, Scheel A, Colombo G, Dietz V, Hornby TG. Effectiveness of automated locomotor training in patients with chronic incomplete spinal cord injury: a multicenter trial. Arch Phys Med Rehabil 2005; 86:672–80. Objective To determine whether automated locomotor training with a driven-gait orthosis (DGO) can increase functional mobility in people with chronic, motor incomplete spinal cord injury (SCI). Design Repeated assessment of the same patients or single-case experimental A-B design. Setting Research units of rehabilitation hospitals in Chicago; Heidelberg, Germany; and Basel and Zurich, Switzerland. Participants Twenty patients with a chronic (>2y postinjury), motor incomplete SCI, classified by the American Spinal Injury Association (ASIA) Impairment Scale with ASIA grades C (n=9) and D (n=11) injury. Most patients (n=16) were ambulatory before locomotor training. Intervention Locomotor training was provided using robotic-assisted, body-weight–supported treadmill training 3 to 5 times a week over 8 weeks. Single training sessions lasted up to 45 minutes of total walking time, with gait speed between .42 and .69m/s and body-weight unloading as low as possible (mean ± standard deviation, 37%±17%). Main outcome measures Primary outcome measures included the 10-meter walk test, the 6-minute walk test, the Timed Up & Go test, and the Walking Index for Spinal Cord Injury–II tests. Secondary measures included lower-extremity motor scores and spastic motor behaviors to assess their potential contribution to changes in locomotor function. All subjects were tested before, during, and after training. Results Locomotor training using the DGO resulted in significant improvements in the subjects' gait velocity, endurance, and performance of functional tasks. There were no significant changes in the requirement of walking aids, orthoses, or external physical assistance. There was no correlation between improvements in walking speed or changes in muscle strength or spastic motor behaviors. Conclusions Intensive locomotor training on a treadmill with the assistance of a DGO results in improved overground walking.

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"Isometric hip and knee torque measu..." refers background or result in this paper

  • ...Although preliminary studies have shown that Lokomat training improves gait in both acute (Hornby et al., 2005), and chronic ISCI subjects (Wirz et al., 2005) there have been no studies documenting the associated changes in the force generating capacity of the lower limb muscles, in subjects as they progress through RAGT using BWSTT Strength changes in lower limb muscles following locomotor training have been previously documented in ISCI subjects using objective outcome measures such as peak torque recorded using a Biodex dynamometer....

    [...]

  • ...In recent years the use of robotic assistance during BWSTT has emerged as an alternative to therapist assisted(Adams et al., 2006; Hicks et al., 2005) or FES assisted BWSTT(Postans et al., 2004) and may provide a more resource efficient method of delivering intensive and progressive gait training (Hornby, Zemon, & Campbell, 2005)....

    [...]

  • ...For acute subjects BWSTT also serves as a method for early lower limb mobilization and exercise....

    [...]

  • ...The observation that acute subjects who positively responded to RAGT had significant increase in peak torques within the first 3 weeks of training, suggests that this type of quantitative monitoring could also be considered as a useful marker in identifying subjects who are positively responding to RAGT using BWSTT....

    [...]

  • ...Although preliminary studies have shown that Lokomat training improves gait in both acute (Hornby et al., 2005), and chronic ISCI subjects (Wirz et al., 2005) there have been no studies documenting the associated changes in the force generating capacity of the lower limb muscles, in subjects as…...

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