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Purpose: To review and characterise biomechanical approaches for the measurement of spasticity as one component of the upper motor neurone syndrome. Method: Systematic literature searches based on defined constructs and a four-step review process of approaches used or described to measure spasticity, its association with function or associated phenomena. Most approaches were limited to individual joints and therefore, to reflect this trend, references were grouped according to which body joint(s) were investigated or whether it addressed a functional activity. For each joint, references were further sub-divided into the types of measurement method described. Results: A database of 335 references was established for the review process. The knee, ankle and elbow joints were the most popular, perhaps reflecting the assumption that they are mono-planar in movement and therefore simpler to assess. Seven measurement methods were identified: five involving passive movement (manual, controlled displacement, controlled torque, gravitational and tendon tap) and two involving active movement (voluntary and functional). Generally, the equipment described was in an experimental stage and there was a lack of information on system properties, such as accuracy or reliability. Patient testing was either by cohort or case studies. The review also conveyed the myriad of interpretations of the concept of spasticity. Conclusions: Though biomechanical approaches provide quantitative data, the review highlighted several limitations that have prevented them being established as an appropriate method for clinical application to measure spasticity.

Purpose: To discuss the measurement of spasticity in the clinical and research environments, make recommendations based on the SPASM reviews of biomechanical, neurophysiological and clinical methods of measuring spasticity and indicate future developments of measurement tools. Method: Using the results of the systematic reviews of the biomechanical, neurophysiological and clinical approaches, methods were evaluated across three dimensions: (1) validity, reliability and sensitivity to change; (2) practical quality such as ease of use and (3) qualities specific to the measurement of spasticity, for example ability to be applied to different muscle groups. Methods were considered in terms of applicability to research and clinical applications. Results: A hierarchy of measurement approaches was identified from highly controlled and more objective (but unrelated to function) to ecologically valid, but less objective and subject to contamination from other variables. The lack of a precise definition of spasticity may account for the problem of developing a valid, reliable and sensitive method of measurement. The reviews have identified that some tests measure spasticity per se, some phenomena associated with spasticity or consequential to it and others the effect of spasticity on activity and participation and independence. Conclusions: Methods appropriate for use in research, particularly into the mechanism of spasticity did not satisfy the needs of the clinician and the need for an objective but clinically applicable tool was identified. A clinical assessment may need to generate more than one ‘value’ and should include evaluation of other components of the upper motor neurone syndrome. There is therefore a need for standardized protocols for ‘best practice’ in application of spasticity measurement tools and scales.

Johnson CA, Burridge JH, Strike PW, Wood DE, Swain ID. The effect of combined use of botulinum toxin type A and functional electric stimulation in the treatment of spastic drop foot after stroke: a preliminary investigation. Arch Phys Med Rehabil 2004;85:902–9. Objective To investigate the effect of combined botulinum toxin type A (BTX) and functional electric stimulation (FES) treatment on spastic drop foot in stroke. Design Nonblinded randomized controlled trial. Setting Hospitals. Participants Consecutive sample of 21 ambulant adults within 1 year after stroke with a spastic drop foot, of whom 18 completed the study. Interventions The treatment group received BTX injections (Dysport) on 1 occasion into the medial and lateral heads of the gastrocnemius (200U each) and tibialis posterior (400U each) muscles and FES, used on a daily basis for 16 weeks to assist walking. Both groups continued with physiotherapy at the same rate. Main outcome measures Walking speed, Physiological Cost Index, Modified Ashworth Scale, Rivermead Motor Assessment, and Medical Outcomes Study 36-Item Short-Form Health Survey. Results Walking speed increased over 12 weeks in both control ( P =.020) and treatment groups (nonstimulated, P =.004; stimulated, P =.042). The baseline corrected (analysis of covariance) increase in mean walking speed at 12 weeks, relative to controls, was .04m/s (95% confidence interval [CI], .003–.090) without stimulation, and .09m/s (95% CI, .031–.150) with stimulation. Conclusions Combined treatment effectively improved walking and function. A larger study is needed to quantify the treatment effect and to investigate its impact on quality of life.

The objective was to inform sample size calculations for a full randomized controlled trial (RCT). The design included an RCT pilot trial with a 16 week study period, including a 4 week baseline phase. The subjects were adults within 1 year of first stroke, ambulant with a spastic dropped foot. Twenty-one participants were recruited from the stroke services of 4 centers. For intervention all participants received physiotherapy; the treatment group also received botulinum neurotoxin Type A (BoNTA) intramuscular injections to triceps surae (800 U Dysport) and functional electrical stimulation (FES) of the common peroneal nerve to assist walking. The main outcome measure was walking speed. The result was a significant upward trend in median walking speed for both the control (p = 0.02) and treatment groups (nonstimulated p = 0.004, stimulated p = 0.042). Trend lines were different in location (p = 0.04 and p = 0.009, respectively). In conclusion, there is evidence of an additional, beneficial effect of BoNTA and FES. Sufficient information has been gained on the variability of the primary outcome measure to inform sample size calculations for a full RCT to quantify the treatment effect with precision.

This study was concerned with individuals who were unable to effectively dorsiflex their ankle when walking, as a result of a lesion of the central nervous system (CNS). Indices that categorise and quantify different patterns of calf and anterior tibial muscle activation patterns during treadmill walking have been derived from a sample of fifteen individuals with established hemiplegia following stroke and twelve age-matched individuals without impairment. As subjects walked on a treadmill, force sensitive foot-switches under the heel and first metatarsal head allowed EMG signals from the calf and anterior tibial muscles to be related to phases of the gait cycle. Normal activation periods for each muscle group were identified as percentiles of the gait cycle and indices for muscle activation periods were derived using ratios of integrated EMG during selected periods. Indices were derived that identified statistically significant differences, between normal and hemiplegic subjects, in calf activation during both push-off phase (P

To assess the clinical effectiveness of the Odstock dropped foot stimulator by analysis of its effect on physiological cost index (PCI) and speed of walking. This functional electrical stimulation (FES) device stimulates the common peroneal nerve during the swing phase of gait.A retrospective study of patients who had used the device for 4 1/2 months.One hundred fifty-one patients with a dropped foot resulting from an upper motor neuron lesion.A medical physics and biomedical engineering department of a district general hospital specializing in the clinical application of FES and a neurophysiotherapy department at a separate hospital.Changes in walking speed and effort of walking, as measured by PCI over a 10-meter course.There was a 92.7% compliance with treatment. Stroke patients showed a mean increase in walking speed of 27% (p.01) and reduction in PCI of 31% (p.01) with stimulation, and changes of 14% (p.01) and 19% (p.01), respectively, while not using the stimulator. Multiple sclerosis patients gained similar orthotic benefit but no "carry-over."The measured differences in walking with and without stimulation were statistically significant in the stroke and multiple sclerosis groups. In this study use of the stimulator improved walking. Those with stroke demonstrated a short-term "carry-over" effect.

Objective: To determine the perceived benefit, pattern and problems of use of the Odstock Dropped Foot Stimulator (ODFS) and the users' opinion of the service provided. Design: Questionnaire sent in a single mailshot to current and past users of the ODFS. Returns were sent anonymously. Setting: Outpatient-based clinical service. Subjects: One hundred and sixty-eight current and 123 past users with diagnoses of stroke (CVA), multiple sclerosis (MS), incomplete spinal cord injury (SCI), traumatic brain injury (TBI) and cerebral palsy (CP). Intervention: Functional electrical stimulation (FES) to correct dropped foot in subjects with an upper motor neuron lesion, using the ODFS. Main outcome measures: Purpose-designed questionnaire. Results:• Return rate 64% current users (mean duration of use 19.5 months) and 43% past users (mean duration of use 10.7 months). • Principal reason cited for using equipment was a reduction in the effort of walking. • Principal reasons identified for discontinuing were an improvement in mobility, electrode positioning difficulties and deteriorating mobility. • There were some problems with reliability of equipment. • Level of service provided was thought to be good. Conclusion: The ODFS was perceived by the users to be of considerable benefit. A comprehensive clinical follow-up service is essential to achieve the maximum continuing benefit from FES-based orthoses.

Summary Contemporary physiotherapy for neurologically impaired patients puts emphasis on the management of spasticity. A randomised controlled trial of the Odstock dropped foot stimulator (ODFS), a common peroneal stimulator used to correct drop-foot during walking, showed a reduction in spasticity of the quadriceps muscles in a sample of 32 chronic hemiplegic subjects. Both treatment (FES) and control groups received a course of ten physiotherapy sessions during the first four weeks of the trial period. The treatment group used the stimulator as part of the physiotherapy sessions and independently each day as they found useful. Both groups received the same amount of therapy contact time. The treatment group continued to use the stimulator for the 12-week period. Assessments also included measurement of walking speed and effort of walking, gait analysis and mobility and quality of life questionnaires. Results of these tests are not presented in this paper but are referred to in relation to changes in spasticity. Spasticity of the quadriceps muscles was measured using the Wartenberg pendulum test. Results showed that during the first four-week period both groups had a reduction in spasticity which was statistically significant in the control group; measured by both the relaxation index (p = 0.005) and the area beneath the curve (p = 0.036) and in the FES group only as the area beneath the curve (p = 0.028) At 12 weeks, reduction in spasticity in the control group was no longer statistically significant in either of these parameters, whereas in the treatment group reduction measured as area beneath the curve was statistically significant (p = 0.001). There was no statistically significant difference between the two groups. These results are discussed in relation to the subject of measurement of spasticity, the effect of physiotherapy on spasticity and observations made on changes in speed and effort of walking.

Study design: Single subject pilot. Objectives: (i) To see whether strength and endurance for recreational cycling by functional electrical stimulation (FES) are possible following spinal cord injury (SCI). (ii) To develop the equipment for FES-cycling. Setting: England. Methods: Near-isometric or cycling exercise was performed by the incomplete SCI subject at home. Results: After training for an average of 21 min per day for 16 months, the stimulated muscles increased in size and the subject was able to cycle for 12 km on the level. Surprisingly, there was a substantial increase in the measured voluntary strength of the knee extensors and the subject reports improved leg function. Conclusion: FES-cycling may promote recovery after incomplete spinal cord injury. If so, it offers the possibility of being a convenient method for widespread use. Sponsorship: Spinal Injuries Unit, Royal National Orthopaedic Hospital, Stanmore.

The Odstock dropped foot stimulator (ODFS) is a foot switch controlled single channel neuromuscular stimulator for correction of dropped foot. Following a randomized controlled trial, the ODFS was recommended for use in the United Kingdom's National Health Service and a clinical service established. The patient performance was assessed by measurement of walking speed over 10 m, physiological cost index (PCI), and by questionnaire. After 4.5 months stroke patients (n = 111) showed a mean increase in walking speed of 27% and reduction in PCI of 31% with stimulation and changes of 14% and 19%, respectively, unassisted. Multiple sclerosis patients (n = 21) gained similar orthotic benefit but no carry over. The principal reason cited for using the equipment was that it reduced the effort of walking. The principal reasons identified for discontinuing were an improvement in mobility, electrode positioning difficulties, and deteriorating mobility. A comprehensive clinical follow-up service is essential to achieve the maximum continuing benefit from FES based orthosis.

Using electrical stimulation of lower limb muscles to assist paraplegics to stand has many advantages over conventional passive standing techniques. However, stability and balance needs to be maintained, in response to muscle spasms and fatigue, postural changes and external perturbations, if the system is to be safe for a subject to take one hand off to perform tasks. The authors' system monitors the stand by measuring the knee angles and uses a closed-loop design, based on a PID (proportional-integral-derivative) type, to respond to deviations by adjusting the stimulation to the quadriceps. With this system the authors have stood 24 paraplegics, with 14 using it at home. The authors report their experience from one of their subjects who started retraining his quadriceps with electrical stimulation in October 1998 and first stood three months later. During sessions over the next three months, he was instructed in standing techniques and the closed-loop algorithm was implemented. The authors found that during standing, if the stimulation increased too quickly then strong stomach spasms resulted. This was improved by removing the controller's derivative term and low-level stimulation of the abdominal muscles as a daily exercise routine.

Objective: To measure the effect of the Odstock Dropped Foot Stimulator (ODFS), a common peroneal stimulator, on the effort and speed of walking. Design: A randomized controlled trial. Subjects: Hemiplegic patients who had suffered a single stroke at least six months prior to the start of the trial whose walking was impaired by a drop-foot. Interventions: The treatment, functional electrical stimulation (FES) group, used the stimulator and received a course of physiotherapy; the control group received physiotherapy alone. Main outcome measures: Changes in walking speed measured over 10 m and the effort of walking measured by physiological cost index (PCI). Results: Thirty-two subjects completed the trial, 16 in the FES group and 16 in the control group. Mean increase in walking speed between the beginning and end of the trial was 20.5% in the FES group (when the stimulator was used), and 5.2% in the control group. Improvement was also measured in PCI with a reduction of 24.9% in the FES group (when the stimulator was used) and 1 % in the control group. No improvement in these parameters was measured in the FES group when the stimulator was not used. Conclusion: Walking was statistically significantly improved when the ODFS was worn but no 'carry-over' was measured. Physiotherapy alone, in this group of subjects with established stroke, did not improve walking.

The authors' involvement in functional electrical stimulation (FES) began 13 years ago when they began investigation into the development of a standing system for complete paraplegics. This work was funded by the Medical Devices Agency of the Department of Health. During the course of this work the authors perceived that there were a number of incomplete paraplegics whose mobility could be improved by the provision of simple FES systems to dorsiflex the foot. At that time there did not appear to be a reliable, commercially available device in the UK. The subsequent grant further developed the stimulator, the Odstock Drop Foot Stimulator (ODFS) and established treatment protocols to improve walking function for patients with a variety of different neurological conditions such as CVA, MS and cerebral palsy as well as incomplete SCI. After the completion of the randomised controlled trial the authors obtain the approval of the South and West Development and Evaluation Committee in early 1996 which has made funding easier in certain areas. This trial showed that in the treatment group walking speed was increased by 21%, the effort involved in walking measured by the Physiological Cost index, PCI, was reduced by 25 %, that reduction in spasticity was more sustained and that patients anxiety and depression levels were reduced. All of these findings were statistically significant. The service has now been running for 5 years. The authors take referrals from both G.P.'s and Consultants and then apply to the patient's local Health Authority or to the G.P. if they are a member of a fund holding practice. (2 pages)