Musculoskeletal modelling in determining the effect of botulinum toxin on the hamstrings of patients with crouch gait

This study aimed to determine the effect of hamstring botulinum toxin A (Btx-A) injection in 10 children with crouch gait in terms of changes in muscle length and lower-limb kinematics. Before Btx-A injection limb kinematics were recorded. Maximum hamstring lengths and excursions were calculated by computer modelling of the lower limb. Data were compared with the averaged hamstring lengths of 10 control children. Hamstrings were denned as short if their length was shorter than the average maximum length minus one standard deviation. Gait analysis was repeated 2 weeks after isolated hamstring Btx-A injection. Pre- and postinjection kinematic data and muscle lengths were then compared. Four of 18 injected limbs in three subjects had short medial hamstring before injection, none of the subjects had short lateral hamstrings. Muscle excursion was significantly reduced in the short and adequate maximum muscle length groups. A significant increase in the semimembranosus and semitendinosus length in all of the injected limbs was noted. Only in the short muscle group was a significant increase in muscle excursion observed. Knee extension improved by 13° in the adequate muscle length group and by 15.6° in the short muscle length group. Pelvic tilt and hip flexion increased in both groups non-significantly. Average walking speed postinjection increased from 0.60 ms^-1 to 0.71 ms^-1. Short hamstrings are over-diagnosed in crouch gait. Hamstring Btx-A injection in patients with crouch gait produces significant, repeatable muscle lengthening and improved ambulatory function.     

Gait Electromyography in Normal and Spastic Children, with Special Reference to Quadriceps Femoris and Hamstring Muscles

Telemetered gait electromyography was used to investigate gait patterns and the phasic behavior of the quadriceps femoris and medial hamstring muscles in 26 normal children and 32 children with spastic cerebral palsy. The average child with spastic cerebral palsy was found to have a shorter stance phase than the normal, but the cadence, while more variable, was nearly the same as normal. The spastic muscles typically exhibited prolonged phasic activity or a dysphasic pattern. Most of the patients with spastic hamstrings also had spastic quadriceps, suggesting that over-weakening the hamstrings may produce an unwanted genu recurvatum or hyperextended knee gait. Care must be taken to balance hamstring spasticity with quadriceps spasticity. A final result with slight knee flexion is preferable to hyperextension.     

Relation between walking speed and muscle strength is affected by somatosensory loss in multiple sclerosis

OBJECTIVE: To evaluate the correlation between gait speed and strength in multiple sclerosis (MS) with particular regard to patients presenting with proprioceptive loss. METHODS: Gait evaluation and isokinetic testing of muscular function were performed in 20 patients with unaided gait (expanded disability status scale < 6). Patients were separated into two groups in relation to the occurrence of somatosensory involvement: pyramidal group (8 patients) and sensory-pyramidal group (12 patients). Ten healthy subjects of similar age, sex, and height constituted a control group to evaluate gait parameters. RESULTS: In the whole patient group, gait speed was reduced and strongly related to hamstring peak torque but not with quadriceps peak torque. The gait speed and peak torques of quadriceps and hamstrings were similar in both groups of patients. However, in the patients with proprioceptive loss there was both a strong correlation between gait speed and hamstring torque and a significant correlation with quadriceps torque. In the pyramidal group there was poor or no correlation. CONCLUSION: In patients with undifferentiated MS there is some correlation between gait speed and muscle strength. In the case of sensory loss, a higher contribution of both flexor and extensors of the lower limbs was observed, suggesting that muscular compensation occurred in this situation to maintain gait speed. These results are relevant to assess rehabilitation modalities in MS.     

Evaluation of a dynamic ankle foot orthosis in hemiplegic gait: A case report

This investigation utilized a single case design to evaluate the effects of a dynamic AFO on ambulation in post stroke hemiplegia. A single patient with stroke related hemiplegia using a dynamic AFO underwent gait analysis while walking on level ground. Outcome measures included temporal-spatial gait parameters and bilateral kinematic joint angles at the ankle, knee, and hip with and without AFO. Walking speed, stride length, step length and cadence increased with the dynamic AFO. Step width and double support decreased, while single support remained unchanged on the affected limb with the dynamic AFO. With the dynamic AFO there was increased hip flexion at foot strike and toe-off, increased hip sagittal plane angular velocity during swing, and decreased abduction. The dynamic AFO had a positive effect on the participant's overall gait which included improved temporal-spatial parameters and gait velocity which is likely due to a decrease in the overall energy cost of walking. Kinematic angles at the hip were most notably affected by brace utilization and this effect should be more fully explored. Further research with a larger sample utilizing dynamic AFOs is indicated to explore the generalizability of these findings and to determine the potential utility of these braces as an alternative to the traditionally prescribed solid AFO.     

Effect of Electrical Stimulation of Hamstrings and L3/4 Dermatome on Gait in Spinal Cord Injury

Objective. To determine the effect of electrical stimulation of hamstrings and L3/4 dermatome on the swing phase of gait. Materials and Methods. Five subjects with incomplete spinal cord injury (SCI) with spasticity were included. Two electrical stimulation methods were investigated, i.e., hamstrings and L3/4 dermatome stimulation. Both interventions were applied during the swing phase of gait. The main outcome measures were step length, maximum hip, and knee flexion during the swing phase of gait. In three subjects changes of spinal inhibition during gait were evaluated using the Hoffman reflex/m (motor)–wave (H/M) ratio at mid swing. Results. The hip flexion decreased 4.6° (p < 0.05) when the hamstrings were stimulated during the swing phase, whereas the knee flexion was not changed. The step length did not change significantly. One subject showed a decrease of the H/M ratio to a nonpathologic level during hamstrings stimulation. Conclusion. It was concluded that hamstrings stimulation during the swing phase results in a reduction of the hip flexion in all five SCI subjects. The H/M ratio of the vastus lateralis was normalized using hamstrings stimulation in one of three subjects. Stimulation of the L3/4 dermatome provides no significant changes in gait performance, but in one subject the H/M ratio increased.     

Is the modified Tardieu scale in semi‐standing position better associated with knee extension and hamstring activity in terminal swing than the supine Tardieu?

The aim of this study was to investigate whether the modified Tardieu scale (MTS) in a semi-standing position, used for the assessment of hamstrings spasticity, was better associated with knee extension and hamstrings activity in terminal swing than the MTS in a supine position in children with cerebral palsy (CP). Seven children diagnosed with spastic CP (Gross Motor Function Classification System Levels I-II) and seven healthy comparison children participated in the study. An instrumented MTS in supine and semi-standing position and an instrumented gait assessment were conducted. Results showed that spasticity-related outcomes of the semi-standing MTS do not show better associations with terminal swing characteristics of gait than the same outcomes of the supine MTS in children with spastic CP. Only the passive restricted knee angle from the supine MTS was strongly associated with the maximum knee extension during gait (r(s)=0.99; p <0.001), suggesting that hamstrings length is more important for terminal swing behaviour than hamstrings spasticity.     

Motor determinants of gait in 100 ambulatory patients with multiple sclerosis

A prospective analysis of gait and strength parameters was performed in 100 patients diagnosed with MS and pyramidal involvement admitted in a rehabilitation unit The patients were divided into two groups based on their ability to walk in daily life (nonassisted or cane-assisted gait) and into four clinical subgroups depending on associated involvements such as sensory loss or cerebellar ataxia. Twenty healthy subjects were studied as a control group. Gait parameters were evaluated with a Locometre and muscle strength with an isokinetic dynamometer. The results showed that the average velocity and strength of the hamstring and quadriceps were strongly correlated and reduced in the MS group in comparison with the control, and in the cane-assisted group compared with the nonassisted group. Gait velocity tended to be more correlated to hamstring strength in the nonassisted group with a determination coefficient (r2) reaching a value of 0.44 in the sensory subgroup. These findings provide evidence that a correlation between strength reduction and gait impairment is obvious whatever the clinical form in patients with MS. This correlation is higher with hamstrings but may change depending on the disability level and the clinical form. This could be taken into account in the individual assessment of further rehabilitation programmes.     

Immediate effects of talus-stabilizing taping on balance and gait parameters in patients with chronic stroke: a cross-sectional study

Background: Talus-stabilizing taping (TST) may improve ankle range of motion and gait performance by providing a posterior–inferior talar glide in a closed-chain dorsiflexion position.

Objectives: This study aimed to investigate the immediate effects of TST on balance and gait parameters in patients with chronic stroke.

Methods: Twenty post-stroke patients participated in this study. Each participant performed tests under three conditions (TST, barefoot, and conventional ankle-foot orthosis [AFO]), in random order. Before testing, the patients walked for 10 min under the three conditions, followed by a 5 min rest period. The outcome measures were static balance ability (SBA), timed up-and-go (TUG) test results, and gait parameters evaluated using a 6-m-long gait mat. One-way repeated measures analysis of variance was used to determine the difference in balance and gait parameters under the three conditions.

Results: SBA more significantly improved in the TST condition than in the barefoot condition. SBA more significantly improved in the conventional AFO condition than in the barefoot condition. The TUG test results more significantly improved in the TST condition than in the conventional AFO and barefoot conditions. Walking speed, cadence, and affected side and unaffected side step and stride lengths more significantly improved in the TST condition than in the conventional AFO and barefoot conditions.

Conclusions: This study used a cross-sectional method and demonstrated that TST improves SBA, TUG, gait speed, cadence, step length, and stride length in patients with chronic stroke.     

Speed and Efficiency in Walking and Wheeling with Novel Stimulation and Bracing Systems After Spinal Cord Injury: A Case Study

To compare various novel and conventional systems for locomotion, a 25‐year‐old man was studied with motor complete spinal cord injury at the T4/5 level. He used various devices in the community, and changes in speed, physiological cost index (PCI), and oxygen consumption were measured periodically. Speed was fastest with a conventional manual wheelchair (nearly 120 m/min in a 4‐min test). Speed was about 30% less, but the PCI was lowest (highest efficiency) using functional electrical stimulation (FES) of the quadriceps and hamstring muscles to propel a novel wheelchair. He walked with knee‐ankle‐foot orthoses (KAFO) at much lower speed (8.8 m/min) and higher PCI. He walked with an alternating gait using a new stance‐control KAFO with FES. The speed was still slow (5 m/min), but he prefers the more normal‐looking gait and uses it daily. Walking with FES and ankle‐foot orthoses (AFO) was slowest (3.5 m/min) and had the highest PCI. In conclusion, the leg‐propelled wheelchair provides a more efficient method of locomotion. A new stance‐controlled KAFO with FES may provide a more acceptable walking system, but must be tested on other subjects.     

Comparison of three ankle-foot orthosis configurations for children with spastic diplegia

This study compared the functional efficacy of three commonly prescribed ankle-foot orthosis (AFO) configurations (solid [SAFO], hinged [HAFO], and posterior leaf spring [PLS]). Sixteen independently ambulatory children (10 males, six females; mean age 8 years 4 months, SD 2 years 4 months; range 4 years 4 months to 11 years 6 months) with spastic diplegia participated in this study. Four children were classified at level I of the Gross Motor Function Classification System (GMFCS; Palisano et al. 1997); the remaining 12 were at level II. Children were assessed barefoot (BF) at baseline (baseline assessment of energy consumption was performed with shoes on, no AFO) and in each orthotic configuration after three months of use, using gait analysis, oxygen consumption, and functional outcome measures. AFO use did not markedly alter joint kinematics or kinetics at the pelvis, hip, or knee. All AFO configurations normalized ankle kinematics in stance, increased step/stride length, decreased cadence, and decreased energy cost of walking. Functionally, all AFO configurations improved the execution of walking/running/jumping skills, upper extremity coordination, and fine motor speed/dexterity. However, the quality of gross motor skill performance and independence in mobility were unchanged. These results suggest that most children with spastic diplegia benefit functionally from AFO use. However, some children at GMFCS level II demonstrated a subtle but detrimental effect on function with HAFO use, shown by an increase in peak knee extensor moment in early stance, excessive ankle dorsiflexion, decreased walking velocity, and greater energy cost. Therefore, constraining ankle motion by using a PLS or SAFO should be considered for most, but not all, children with spastic diplegia.     

RECTUS FEMORIS TRANSFER TO IMPROVE KNEE FUNCTION OF CHILDREN WITH CEREBRAL PALSY

Stance phase stability and swing phase clearance, prerequisites for normal ambulation, often are lost in the gait of children with cerebral palsy. Lengthening of the hamstrings usually will improve stance-phase knee extension but will not greatly alter swing-phase knee flexion. This paper presents the outcome of transfer of the distal end of the rectus femoris in conjunction with hamstrings lengthening in 37 knees, and compares it with a control group of 24 knees in which only hamstrings lengthening was done. In the first group swing-phase knee flexion was improved by 16.0 +/- 14.4 degrees, compared to 9.5 +/- 7.5 degrees in the control group, and residual knee flexion in stance was reduced to 8.9 +/- 8.1 degrees, compared to 15.1 +/- 13.8 degrees in the controls. Poor outcome in the transfer-plus-lengthening group was associated mainly with foot rotation in excess of 8 degrees internally or externally, or postoperative knee flexion in stance. Criteria for selection of cases and methods of improving surgical outcome are discussed.     

Effect of multilevel botulinum toxin a and comprehensive rehabilitation on gait in cerebral palsy

To evaluate the effect of multilevel botulinum toxin A and comprehensive rehabilitation on gait pattern, muscle length, and spasticity, a multicenter randomized trial was performed in 46 children with spastic cerebral palsy who walk with flexed knees. Their mean age was 8.0 years (range 4 to 11 years). They were randomly allocated to the intervention group (multilevel botulinum toxin A and comprehensive rehabilitation) or the control group (usual care). After 6 weeks, a significant treatment effect in the intervention group was observed on: improved knee extension during midstance and terminal swing (7 degrees and 5 degrees , P < 0.01, respectively); hip rotation during terminal swing (4 degrees , P = 0.02); gait score (1.7, P < 0.01); decreased spasticity in hamstrings (11 degrees , P < 0.01), gastrocnemius (6 degrees , P = 0.01), and soleus (5 degrees , P = 0.02); and increased muscle length in hamstrings (9 degrees , P < 0.01) and gastrocnemius (5 degrees , P < 0.01). The improved muscle length was maintained up to 24 weeks. This study demonstrated that multilevel botulinum toxin A and comprehensive rehabilitation improves knee extension during gait, increases muscle length, and decreases spasticity in injected muscles after 6 weeks in children who walk with flexed knees. Although the effect on muscle length was maintained after 24 weeks, the effect on gait and spasticity had disappeared.     

Effects of carbon fibre spring orthoses on gait in ambulatory children with motor disorders and plantarflexor weakness

A consecutive series of 17 children (six males, 11 females; mean age 11y 11mo [SD 4y 5mo]; range 3y 11mo-17y 4mo) with plantarflexor weakness was assessed to compare gait differences between a carbon fibre spring orthosis (CFSO) and participants' regular orthoses. Twelve children had myelomeningocele, four children had arthrogryposis, and one child had neuropathy with peripheral muscle pareses. All participants underwent clinical examination and 3D gait analysis. Parents answered a questionnaire to assess subjective perceptions of the orthoses. Results from 3D gait analysis provided evidence that CFSOs enhance gait function in most participants by improving ankle plantarflexion moment (p<0.001), ankle positive work (p<0.001), and stride length (p<0.001). The CFSO did not suit all participants, which emphasizes the importance of analyzing each patient's needs.     

Comparison of three ankle-foot orthosis configurations for children with spastic hemiplegia

The purpose of this study was to examine the effectiveness of the hinged ankle-foot orthosis (HAFO), posterior leaf spring (PLS), and solid ankle-foot orthosis (SAFO), in preventing contracture, improving efficiency of gait, and enhancing performance of functional motor skills in 30 children (21 male, 9 female; mean age 9 years 4 months; age range 4 to 18 years,) with spastic hemiplegia. Following a 3-month baseline period of no ankle-foot orthosis (AFO) use, each AFO was worn for 3 months after which ankle range of motion, gait analysis, energy consumption, and functional motor skills were assessed. The HAFO and PLS increased passive ankle dorsiflexion and normalization of ankle rocker function during gait. Normalization of knee motion in stance was dependent upon the knee abnormality present and AFO configuration. The HAFO was the most effective in controlling knee hyperextension in stance, while PLS was the most effective in promoting knee extension in children with >10 degree knee flexion in stance. Energy efficiency was improved in 21 of the children, with 13 of these children demonstrating the greatest improvement in HAFO and PLS. Improvements in functional mobility were greatest in the HAFO and PLS.     

Discrete gait characteristics are associated with m.3243A>G and m.8344A>G variants of mitochondrial disease and its pathological consequences

Mitochondrial disease is complex and variable, making diagnosis and management challenging. The situation is complicated by lack of sensitive outcomes of disease severity, progression, contributing pathology and clinical efficacy. Gait is emerging as a sensitive marker of pathology; however, to date, no studies have quantified gait in mitochondrial disease. In this cross-sectional study, we quantified gait characteristics in 24 patients with genetically confirmed mitochondrial disease (m.3243A>G and m.8344A>G) and 24 controls. Gait was measured using an instrumented walkway according to a predefined model with five domains hypothesised to reflect independent features of the neural control of gait in mitochondrial disease, including: pace (step velocity and step length); rhythm (step time); variability (step length and step time variability); asymmetry (step time asymmetry); and postural stability (step width, step width variability and step length asymmetry). Gait characteristics were compared with respect to controls and genotype. Additional measures of disease severity, pathophysiology and imaging were also compared to gait to verify the validity of gait characteristics. Discrete gait characteristics differed between controls and mitochondrial disease groups, even in relatively mildly affected patients harbouring the m.3243A>G mutation. The pattern of gait impairment (increased variability and reduced postural control) was supported by significant associations with measures of disease severity, progression, pathophysiology and radiological evidence of cerebellar atrophy. Discrete gait characteristics may help describe functional deficits in mitochondrial disease, enhance measures of disease severity and pathology, and could be used to document treatment effects of novel therapies.     

A gait nomogram used with fuzzy clustering to monitor functional status of children and young adults with cerebral palsy

We have developed a gait nomogram based on dynamic similarity to characterize and compare neuromuscular function. We used temporal-distance data based on 669 normal participants (age range 5 to 98 years), and 78 children and young adults with spastic diplegia (43 males, 35 females; mean age 10 y 8 mo, standard deviation 3 y 11 mo, range 5 to 20 y), all of whom were independent ambulators. A new statistical algorithm known as fuzzy clustering was implemented and five cluster centres were identified, each representing distinct walking strategies adopted by children with cerebral palsy. Using just three easily obtained parameters--leg length in metres, stride length in metres, and cadence in steps per minute--our program calculates a child's dimensionless step length and step frequency, generates the individual's membership values for each of the five clusters, and plots the gait nomogram. The clinical utility of our approach has been demonstrated for two test participants with spastic diplegia, using pre- and postoperative data (one neurosurgical and one orthopaedic), where changes in membership of the five clusters provide objective measures of improvement in their neuromuscular function.     

Comparative analysis of the gait disorder of normal pressure hydrocephalus and Parkinson's disease

OBJECTIVES: Comparative gait analyses in neurological diseases interfering with locomotion are of particular interest, as many hypokinetic gait disorders have the same main features. The aim of the present study was (1) to compare the gait disturbance in normal pressure hydrocephalus and Parkinson's disease; (2) to evaluate which variables of the disturbed gait pattern respond to specific treatment in both diseases; and (3) to assess the responsiveness to visual and acoustic cues for gait improvement. METHODS: In study 1 gait analysis was carried out on 11 patients with normal pressure hydrocephalus, 10 patients with Parkinson's disease, and 12 age matched healthy control subjects, on a walkway and on a treadmill. In study 2, patients with normal pressure hydrocephalus were reinvestigated after removal of 30 ml CSF, and patients with Parkinson's disease after administration of 150 mg levodopa. In part 3 visual cues were provided as stripes fixed on the walkway and acoustic cues as beats of a metronome. RESULTS: The gait disorder in both diseases shared the feature of a reduced gait velocity, due to a diminished and highly variable stride length. Specific features of the gait disturbance in normal pressure hydrocephalus were a broad based gait pattern with outward rotated feet and a diminished height of the steps. After treatment in both diseases, the speed increased, due to an enlarged stride length, now presenting a lower variability. All other gait variables remained unaffected. External cues only mildly improved gait in normal pressure hydrocephalus, whereas they were highly effective in raising the stride length and cadence in Parkinson's disease. CONCLUSION: The gait pattern in normal pressure hydrocephalus is clearly distinguishable from the gait of Parkinson's disease. As well as the basal ganglia output connections, other pathways and structures most likely in the frontal lobes are responsible for the gait pattern and especially the disturbed dynamic equilibrium in normal pressure hydrocephalus. Hypokinesia and its responsiveness to external cues in both diseases are assumed to be an expression of a disturbed motor planning.     

Lumbar disc herniation and tight hamstrings syndrome in adolescence

BACKGROUND: Lumbar intervertebral disc herniation is infrequently encountered in children and adolescents. Additional signs and symptoms such as postural deformities and abnormal gait accompany the classical findings of lumbar root irritation. These unusual signs have been described in the literature as "tight hamstrings syndrome". Waddling gait with flexed knees is considered as pathognomonic for this condition and may be masked by the signs of root irritation due to prolapsed intervertebral disc material. CASE REPORT AND DISCUSSION: We report an adolescent patient with lumbar disc herniation in whom gait abnormality and limitation of lumbar movements persisted after surgical intervention. A review of the literature on tight hamstrings is presented.     

"Task-oriented" exercise improves hamstring strength and spastic reflexes in chronic stroke patients.

BACKGROUND AND PURPOSE: Despite the belief that after cerebral infarction only limited functional gains are possible beyond the subacute period, we tested the hypothesis that a 12-week program of "task-oriented" treadmill exercise would increase muscle strength and decrease spastic reflexes in chronic hemiparetic patients. METHODS: Fourteen subjects, aged 66+/-3 (mean+/-SEM) years, with residual gait deviations due to remote stroke (>6 months), underwent repeated measures of reflexive and volitional (concentric and eccentric) torque with use of isokinetic dynamometry on the hamstring musculature bilaterally. Torque output was measured at 4 angular velocities (30(o), 60(o), 90(o), and 120(o)/s). RESULTS: After 3 months of 3 times/wk low-intensity aerobic exercise, there were significant main effects (2 legs [P<0.01]x2 times [P<0. 01]x4 angular velocities [P<0.05]) for concentric torque production. Torque/time production in the concentric mode also improved significantly in the paretic (50%, P<0.01) and nonparetic hamstrings (31%, P<0.01). Eccentric torque/time production increased by 21% (P<0.01) and 22% (P<0.01) in the paretic and nonparetic hamstrings, respectively. Passive (reflexive) torque/time generation in the paretic hamstrings decreased by 11% (P<0.027). Reflexive torque/time was unchanged in the nonparetic hamstrings (P=0.45). CONCLUSIONS: These findings provide evidence that progressive treadmill aerobic exercise training improves volitional torque and torque/time generation and reduces reflexive torque/time production in the hemiparetic limb. Strength changes associated with improved functional mobility in chronic hemiparetic stroke survivors after treadmill training will be reported in future articles.     

Preliminary trial of botulinum toxin A therapy for lower extremity spasticity in children with cerebral palsy

Eleven children with gait disturbance due to cerebral palsy (mean age, 5.6 years, ranging from 2.4 to 11.5) were treated with Botulinum toxin A (BTA, BOTOX, Allergan) for improvement of spasticity and walking difficulty. BTA was injected into the gastrocnemius, adductors, and hamstring muscles with an initial total dose up to 8 units/kg or 100 units. Spasticity and gait disturbance were significantly improved in all patients 4 weeks after the treatment. Their parents also reported that BTA was helpful for brace tolerance and assistance of caregivers. No side effects including worsening of gait or signs of systemic adverse effects were observed. Management of leg spasticity with BTA is thought to be useful and safe, and approval for this use in Japan is recommended.