A functional electrical stimulation system improves knee control in crouch gait

BackgroundCrouch gait is a major sagittal plane deviation in children diagnosed with cerebral palsy (CP). It is defined as a combination of excessive ankle dorsiflexion and knee and hip flexion throughout the stance phase. To the best of our knowledge, functional electrical stimulation (FES) has not been used to decrease the severity of crouch gait in CP subjects and assist in achieving lower limb extension.PurposeTo evaluate the short- and long-term effects of FES to the quadriceps muscles in preventing crouch gait and achieving ankle plantar flexion, knee and hip extension at the stance phase.MethodsAn 18-year-old boy diagnosed with CP diplegia [Gross Motor Function Classification System (GMFCS) level II] was evaluated. The NESS L300^® Plus neuroprosthesis system provided electrical stimulation of the quadriceps muscle. A three-dimensional gait analysis was performed using an eight-camera system measuring gait kinematics and spatiotemporal parameters while the subject walked shod only, with ground reaction ankle foot orthotics (GRAFOs) and using an FES device.ResultsWalking with the FES device showed an increase in the patient’s knee extension at midstance and increased knee maximal extension at the stance phase. In addition, the patient was able to ascend and descend stairs with a “step-through” pattern immediately after adjusting the FES device.ConclusionsThis report suggests that FES to the quadriceps muscles may affect knee extension at stance and decrease crouch gait, depending on the adequate passive range of motion of the hip, knee extension, and plantar flexion. Further studies are needed in order to validate these results.     

The influence of ankle-foot orthoses on gait and energy expenditure in spina bifida

We examined the effect of ankle-foot orthoses (AFOs) on gait and energy expenditure in children with spina bifida. Nine boys and three girls, 6 to 16 years of age, took part in the study. There were four children each with L4, L5, and sacral level lesions. Each child underwent gait analysis and energy consumption studies with and without AFOs. Walking speed was faster with AFOs (mean, 58 m/min) than without (mean, 50 m/min, p < 0.01). Stride length improved significantly (p < 0.001) from 0.89 m barefoot to 1.08 m with AFOs. Double support time was decreased from 0.32 seconds barefoot to 0.28 seconds with AFOs (p < 0.05). The oxygen cost of walking was significantly better with (0.33 mL/kg/m) than without AFOs (0.41 mL/kg/m, p < 0.001). Hip flexion at initial contact was increased. Ankle kinematics were unchanged, but ankle power generation showed a significant improvement; from 0.5 W/kg barefoot to 1.3 W/kg with AFOs. Increased ankle power generation results in improved hip flexion and stride length, which contributes to increased walking speed and reduced oxygen cost. The stability conferred by the AFOs is reflected in the reduced time spent in double support.     

The effect of community-prescribed ankle–foot orthoses on gait parameters in children with spastic cerebral palsy

Purpose To evaluate the efficacy of ankle foot orthoses (AFOs) prescribed in the community for children with cerebral palsy (CP). Methods Fifty-six children (32 boys and 24 girls, mean age 8.9 years, range 4–17) who were diagnosed as having CP were enrolled. They were grouped according to the type of CP, diplegic (n = 38) and hemiplegic (n = 18). Three-dimensional gait analyses while patient were barefoot and with AFOs were obtained and analyzed. Results The spatio-temporal findings were the most significantly changed as a result of AFO use. In the hemiplegic group, stride length was 11.7% (p = 0.001) longer with AFOs in both affected (10.2%) and non-affected (12.4%) legs, and cadence was reduced by 9.7%; walking speed was not affected. In the diplegic group, stride length with AFOs was 17.4% longer compared to barefoot (p < 0.001) and walking velocity improved by 17.8% (p < 0.001); cadence was unchanged. AFOs also increased ankle dorsiflexion at initial contact in both groups. In the hemiplegic group, AFOs produced an average 9.4° increase of dorsiflexion at initial contact (IC) on the affected side (p < 0.001) and 5.87° on the unaffected side (p = 0.007), and an increase of 9.9° (p < 0.001) dorsiflexion at swing, on the affected side. In the diplegic group, dorsiflexion at IC was increased by 13.4° on the right side and 7.8° on the left side (p = 0.05; p > 0.001, respectively) and an increase of 6° (p = 0.005) at swing. In the hemiplegic group of patients, knee flexion at initial contact on the affected side was reduced by 8.5° (p = 0.032) while in the diplegic group we found no influence. The number of patients that reached symmetry at initial double support tripled (from 5.6 to 16.7%) with the use of AFOs. Conclusions Our results showed that the use of AFOs improves spatio-temporal gait parameters and gait stability in children with spastic cerebral palsy. It has a lesser effect on proximal joint kinematics. Children with spastic hemiplegia display greater improvement than those with spastic diplegia.     

Comparison of hamstring transfer with hamstring lengthening in ambulatory children with cerebral palsy: further follow-up

Background

Overactivity or contractures of the hamstring muscles in ambulatory children with cerebral palsy (CP) can lead to either a jump gait (knee flexion associated with ankle plantar flexion) or a crouch gait (knee flexion associated with ankle dorsiflexion). Hamstring lengthening is performed to decrease stance knee flexion. However, this procedure carries the potential risk of weakening hip extension power as well as recurrence over time; therefore, surgeons have adopted a modified procedure wherein the semitendinosus and gracilis are transferred above the knee joint, along with lengthening of the semimembranosus and biceps femoris.

Purpose

The purpose of our study is to evaluate the differences between hamstring lengthening alone (HSL group) and hamstring lengthening plus transfer (HST group) in the treatment of flexed knee gait in ambulatory children with CP. We hypothesized that recurrence of increased knee flexion in the stance phase will be less in the HST group at long-term follow-up, and hip extensor power will be better preserved.

Methods

Fifty children with CP who underwent hamstring surgery for flexed knee gait were retrospectively reviewed. All subjects underwent a pre-operative gait study, a follow-up post-operative gait study, and a long-term gait study. The subjects were divided into two groups; HSL group (18 subjects) or HST group (32 subjects). The mean age at surgery was 9.9 ± 3.3 years. The mean follow-up time was 4.4 ± 0.9 (2.7–6.3) years.

Results

On physical examination, both groups showed improvement in straight leg raise, knee extension, popliteal angle, and maximum knee extension in stance at the first post-op study, and maintained this improvement at the long-term follow-up, with the exception of straight leg raise, which slightly worsened in both groups at the final follow-up. Both groups improved maximum knee extension in stance at the initial follow-up, and maintained this at the long-term follow-up. Only the HST group showed significant (p < 0.05) improvement in the peak hip extension power in stance at the first post-op study, and this increased further at the final follow-up. In the HSL group, there was an initial slight decrease in the hip extension power, which subsequently increased to pre-operative values at the long-term study. Only the HST group showed increase of the average anterior pelvic tilt at the long-term follow-up study, although this was small in magnitude. There were two subjects who developed knee recurvatum at the post-op study, and both were in the HST group.

Conclusions

There is no clear benefit in regards to recurrence when comparing HST to HSL in the long term. In both HSL and HST, there was reduction of stance phase knee flexion in the long term, with no clear advantage in either group. Longer follow-up is needed for additional recurrence information. There was greater improvement of hip extension power in the HST group, which may justify the additional operative time of the transfer.

Significance

This study helps pediatric orthopedic surgeons choose between two different techniques to treat flexed knee gait in patients with CP by showing the long-term outcome of both procedures.     

Analysis of hip dysplasia and spinopelvic alignment in cerebral palsy

Background contextKnowledge of sagittal spinopelvic parameters and hip dysplasia is important in cerebral palsy (CP) patients because these parameters differ from those found in the general population and can be related to symptoms.PurposeThe purpose of this study was to analyze sagittal spinopelvic alignment and determine its relation to hip dysplasia in CP patients.Study designRadiological analysis was conducted on patients with CP.Patient sampleFifty-four patients with CP and 24 normal controls were included in this study.Outcome measuresParticipants underwent radiographs of the whole spine.MethodsThe patient and control groups comprised 54 CP patients and 24 volunteers, respectively. All underwent lateral radiography of the whole spine and hip joint anteroposterior radiography. The radiographic parameters examined were sacral slope, pelvic tilt, pelvic incidence, S1 overhang, thoracic kyphosis, thoracolumbar kyphosis, lumbar lordosis, sagittal balance, center edge angle, acetabular angle, and migration index. Statistical analysis was performed to identify significant differences and correlations between the two groups.ResultsSacral slope, thoracolumbar kyphosis, lumbar lordosis, sagittal balance, acetabular angle, and migration index were significantly higher in CP patients, whereas pelvic tilt, S1 overhang, and center edge angle were significantly lower (p<.05). Correlation analysis revealed that pelvic incidence, sacral slope, pelvic tilt, and S1 overhang were related to each other and that thoracolumbar kyphosis was related to the thoracic kyphosis and lumbar lordosis (p<.05). For spinal and pelvic parameters, lumbar lordosis was related to sacral slope, pelvic incidence, pelvic tilt, and S1 overhang; for hip dysplasia parameters, center edge angle and acetabular angle were found to be interrelated (p<.05). Regarding symptoms, pelvic tilt, S1 overhang, and thoracolumbar kyphosis were found to be correlated with symptom severity in patients. However, no hip dysplasia parameters were found to be related to hip or spinal symptoms.ConclusionsThis study found significant differences between CP patients and normal controls in terms of spinopelvic alignment and hip dysplasia. Furthermore, relationships were found between the sagittal spinopelvic parameters and hip dysplasia, and correlations were found between sagittal spinopelvic parameters and pain.     

Knee joint sagittal plane movement in cerebral palsy: a comparative study of 2-dimensional markerless video and 3-dimensional gait analysis

Background and purpose — Gait analysis is indicated in children with cerebral palsy (CP) to identify and quantify gait deviations. One particularly difficult-to-treat deviation, crouch gait, can progress in adolescence and ultimately limit the ability to ambulate. An objective quantitative assessment is essential to early identify progressive gait impairments in children with CP. 3-dimensional gait analysis (3D GA) is considered the gold standard, although it is expensive, seldom available, and unnecessarily detailed for screening and follow-up. Simple video assessments are time-consuming when processed manually, but more convenient if used in conjunction with video processing algorithms; this has yet been validated in CP. We validate a 2-dimensional markerless (2D ML) assessment of knee joint flexion/extension angles of the gait cycle in children and young adults with CP.

Patients and methods — 18 individuals, mean age 15 years (6.5–28), participated. 11 had bilateral, 3 unilateral, 3 dyskinetic, and 1 ataxic CP. In the Gross Motor Function Classification System, 6 were at level I, 11 at level II, and 1 at level III. We compared 2D ML, using a single video camera with computer processing, and 3D GA.

Results — The 2D ML method overestimated the knee flexion/extension angle values by 3.3 to 7.0 degrees compared with 3D GA. The reliability within 2D ML and 3D GA was mostly good to excellent.

Interpretation — Despite overestimating, 2D ML is a reliable and convenient tool to assess knee angles and, more importantly, to detect changes over time within a follow-up program in ambulatory children with CP.     

Gait analysis outcomes of percutaneous medial hamstring tenotomies in children with cerebral palsy

BACKGROUND: Hamstring lengthening procedures are commonly performed on children with cerebral palsy (CP) to improve gait. The purpose of this study was to determine the efficacy of percutaneous hamstring tenotomy surgery for children with ambulatory CP. METHODS: In this retrospective study, subjects were included if they had a diagnosis of CP and had computerized gait analysis data collected before and after surgery. Subjects were not included in the study if they had any open hamstring lengthening on the same side. Other concomitant lower extremity surgeries were not exclusionary. Short- and long-term follow-up groups were established: if the time from their surgery to their gait laboratory was less than 18 months, they were placed in the short-term follow-up group, and if the time from their surgery to their gait laboratory was greater than 18 months, they were placed in the long-term follow-up group. RESULTS: The results demonstrated that for short- and long-term groups on preoperative to postoperative analysis, there was significantly improved knee extension at initial contact, increased velocity, increased stride length, improved overall gait as indicated by a decrease in a 16 variable multivariate index (Gillette Gait Index), and a decreased popliteal angle. For the short-term group only, additional significant findings included increased peak knee extension in stance and reduced plantar flexion at initial contact. The absolute values of peak knee extension in stance and plantar flexion at initial contact were equivalent at follow-up for the short- and long-term groups. Increased anterior pelvic tilt was also significant for the short-term follow-up group only. CONCLUSIONS: The findings of this study demonstrate that the minimally invasive technique of percutaneous hamstring tenotomy is effective in improving key dynamic gait parameters for individuals with CP for a short period, and these benefits are maintained in the long term. LEVEL OF EVIDENCE: Level IV.     

Gait abnormalities following slipped capital femoral epiphysis

The authors evaluated 30 subjects with treated unilateral slipped capital femoral epiphysis and a range of severity from mild to severe to characterize gait and strength abnormalities using instrumented three-dimensional gait analysis and isokinetic muscle testing. For slip angles less than 30 degrees, kinematic, kinetic, and strength variables were not significantly different from age- and weight-matched controls. For moderate to severe slips, as slip angle increased, passive hip flexion, hip abduction, and internal rotation in the flexed and extended positions decreased significantly. Persistent pelvic obliquity, medial lateral trunk sway, and trunk obliquity in stance increased, as did extension, adduction, and external rotation during gait. Gait velocity and step length decreased with increased amount of time spent in double limb stance. Hip abductor moment, hip extension moment, knee flexion moment, and ankle dorsiflexion moment were all decreased on the involved side. Hip and knee strength also decreased with increasing slip severity. All of these changes were present on the affected and to a lesser degree the unaffected side. Body center of mass translation or pelvic obliquity in mid-stance greater than one standard deviation above normal correlated well with the impression of compensated or uncompensated Trendelenburg gait.     

Effects of ankle-foot orthoses on the gait of children

Gait analysis was performed on five normal children walking barefoot with bilateral double-upright ankle-foot orthoses (AFOs) and with plastic AFOs. When orthoses were worn, walking speed and cadence were reduced and quadriceps EMG timing was prolonged. Changes in lower extremity motions and torques were observed. The metal-and-leather AFOs impaired normal walking, more than the plastic orthoses. This study provides baseline information for evaluation of new orthotic designs and materials for children. In clinical practice, this information may be useful in selection of orthotic materials for some patients.     

Treatment of fixed knee flexion deformity and crouch gait using distal femur extension osteotomy in cerebral palsy

Purpose

The purpose of this study was to evaluate the results of distal femur extension osteotomy and medial hamstring lengthening in the treatment of fixed knee flexion deformity in patients with spastic diparetic cerebral palsy.

Methods

A retrospective study was done in a group of 12 diparetic cerebral palsy patients. A distal femur extension osteotomy was performed as part of multilevel surgery on lower limbs. The fixed knee flexion deformity was measured during physical examination, whereas hip and knee flexion in the stance phase and anterior pelvic tilt were both analyzed at kinematics. The pre- and post-surgery results were compared and analyzed statistically. A medical record review was done in order to identify the complications. The mean follow-up was 28 months.

Results

A significant reduction of fixed knee flexion deformity at physical examination and knee flexion in the stance phase at kinematics was observed, but with no decrease in hip flexion. As a non-desired effect, there was an increase in anterior pelvic tilt after surgical procedures. With regard to complications, a single patient had skin breakdown at a calcaneous area on one side and the recurrence of deformity was seen in 27% of cases.

Conclusions

In this study, in which fixed knee flexion deformity did not exceed 40° before surgery, the distal femur extension osteotomy was effective in increasing knee extension in the stance phase. However, an increase in anterior pelvic tilt, deformity recurrence and necessity for walking aids are possible complications of this procedure.     

Evaluation of a novel powered gait orthosis for walking by a spinal cord injury patient

BACKGROUND: The aim of this case study was to analyze the effect on gait parameters of a new design of powered gait orthosis which applied synchronized motions to both the hip and knee joints when utilized for walking by a spinal cord injury (SCI) patient. CASE DESCRIPTION AND METHODS: Two orthoses were evaluated while worn by an incomplete SCI subject. Gait evaluation was performed when walking with an isocentric reciprocating gait orthosis (IRGO) and compared to that demonstrated by a newly developed powered version. This new orthosis was based on the IRGO superstructure but incorporated powered hip and knee joints using electrically motorized actuators. FINDINGS AND OUTCOMES: These gait parameters were improved when compared to standard IRGO and initial testing with the orthosis with only the hip or the knee joints activated in isolation. Maximum hip flexion and extension angles, as well as the maximum knee flexion and extension angles all increased when walking with the powered RGO compared to the IRGO. CONCLUSIONS: Gait evaluation of this newly developed orthosis showed improvement in measured parameters when compared to walking with an IRGO. Clinical relevance This case study gave the authors confidence to extend the research to a more extensive study with a group of SCI patients.     

Proximal rectus femoris release surgery is not effective in normalizing hip and pelvic variables during gait in children with cerebral palsy

The purpose of this study was to determine the efficacy of the proximal rectus femoris release to treat hip flexor contractures and hip and pelvic gait deviations in children with spastic cerebral palsy. This study was a retrospective repeated-measures analysis of data collected on two matched groups of patients, those with and without proximal rectus femoris release surgery, seen in our Motion Analysis Laboratory. Proximal rectus release surgery did not improve hip extension, did not decrease anterior pelvic tilt, and did not improve temporal-distance measures of gait in children with cerebral palsy. A multivariate measure, the Hip Flexor Index, was also unchanged. The group of patients without any hip flexor surgery was not different from the rectus femoris release group on hip or pelvic variables before or after surgery. The findings of this study offer no evidence that the proximal rectus femoris release is successful in achieving desired gait outcomes at the hip and pelvis in children with cerebral palsy.     

Effects of intramuscular psoas lengthening on pelvic and hip motion in patients with spastic diparetic cerebral palsy

The effects of intramuscular psoas lengthening on gait in cerebral palsy patients have been the subject of debates, and the indications for such procedure are still controversial. The purpose of this study was to evaluate the effects of intramuscular psoas lengthening on sagittal plane pelvic and hip motion in patients with spastic diparetic cerebral palsy and identify the factors linked to the best possible outcome. A retrospective study was performed in 26 independent ambulatory patients. All of them had undergone an intramuscular psoas lengthening over the pelvic brim. The mean age at the time of surgery was 11.10 years, and most cases went through additional simultaneous procedures. A complete gait analysis was performed before and, on average, at 17.69 months (range, 6-39 months) after surgery. The Thomas test values, maximum hip extension in stance, and pelvic tilt were analyzed before and after surgical intervention, and the results were statistically compared. The most significant postoperative effect was the reduction of pelvic range of motion (P < 0.01). Reduction of anterior pelvic tilt was observed only in those patients with no previous need of an external aid (P < 0.01), and the studied group did not show a significant improvement of hip extension at terminal stance. According to the results, intramuscular psoas lengthening was useful in reducing pelvic range of motion at the sagittal plane, but this study also suggests that pelvic and hip disruptions of the same plane (sagittal) seem to have a multifactorial etiology. The use of external assistive devices in patients with balance problems may lead to increased anterior pelvic tilt as well as reduction of hip extension at terminal stance.     

Electromyographic test to differentiate mild diplegic cerebral palsy and idiopathic toe-walking.

The purpose of this study was to determine whether children with mild spastic diplegic cerebral palsy (CP) could be differentiated from those with idiopathic toe-walking (ITW) based on an obligatory coactivation during voluntary contraction of the quadriceps or gastrocnemius. Twenty-four subjects participated in this study, eight children with mild spastic diplegia CP, eight with ITW, and eight age-matched controls. Measurements included passive range of motion and surface electromyographic recordings of the lateral quadriceps and lateral gastrocnemius. Electromyographic recordings were obtained during resisted knee extension with knee flexed 30 degrees, isometric quadriceps contraction with knee extended (quad set), active plantarflexion, and during gait. The range-of-motion values were not different between the CP and ITW subjects, with the exception of the popliteal angle, which was greater in subjects with CP, with an overlap in values. Gait electromyography showed premature firing of gastrocnemius in swing in both groups of subjects compared with controls. During resisted knee extension and quad set, the mean duration of gastrocnemius coactivation in subjects with CP was high: 86% and 86% compared with 20% and 35% for the subjects with ITW and 0.4% and 3% for controls, respectively. Voluntary plantarflexion did not consistently elicit coactivation of the quadriceps. The results suggest that electromyographic testing of resisted knee extension and quad set to identify gastrocnemius coactivation can help differentiate patients with mild CP from those with ITW.     

Gait improvement surgery in diplegic children: how long do the improvements last?

Gait improvement surgery in ambulatory children with cerebral palsy performed as single-event multilevel surgery is today a well-established modality of treatment, but follow-up studies are lacking. Preoperative and follow-up gait analysis data of 32 diplegic children who underwent single-event multilevel surgery for gait improvement between 1995 and 1998 were evaluated retrospectively. Relevant sagittal plane kinematic parameters of the hip, knee, and ankle joint and time-distance parameters were considered for outcome measures in this study. Postoperative gait analysis was performed three times in all the cases: after discontinuation of the dynamic AFOs (mean 1.0 +/- 0.3 years), after discontinuation of the night splints (mean 2.3 +/- 0.7 years), and at least 1.5 years after discontinuation of physiotherapy and splints (mean 4.4 +/- 1.1 years). The aim of the study was to ascertain whether the improvements in gait function were maintained over these examinations. The authors found that gait function continued to change over 1, 2, and 3 years of follow-up. A general decrease in gait function was measurable in this collective between the first postoperative and the second postoperative evaluations. The results indicate that evaluation of gait improvement surgery in cerebral palsy performed at a minimum of 3 years after surgery would give the most predictive outcome of treatment.     

Analysis of Joint Power and Work During Gait in Children With and Without Cerebral Palsy

PurposeTo compare joint work in the lower limb joints during different sub-phases of the gait cycle between Cerebral Palsy (CP) and healthy children.MethodsEighteen CP and 20 healthy children’s gait data were collected. The CP group included orthoses, intra-muscular injection of botulinum toxin and surgery groups. A motion capture system was used to collect gait data. Joint work was calculated as positive and negative components in six subphases during gait and normalised by speed when comparing the groups.ResultsThe CP group had a slower walking speed, smaller stride length and longer stance phase than the healthy group. Hip max positive work was 0.12 ± 0.02 Jkg⁻¹/ms⁻¹ for the CP group in pre-mid-stance but 0.07 ± 0.01 Jkg⁻¹/ms⁻¹ for the healthy group during the terminal phase. In terminal stance, ankle positive work was significantly lower in the CP group (0.12 ± 0.01) than in the healthy group (0.18 ± 0.01). The knee showed a similar distribution of positive work in the stance phase for the two groups. In the ankle and hip, the CP group had energy generation mainly in midstance while the healthy group was mainly in terminal stance. In the ankle, the CP group had larger energy absorption in mid-stance than the healthy children group, while the CP group showed lower energy generation in the terminal stance phase than seen in the healthy group.ConclusionThe qualitative and quantitative analysis of joint work provides useful information for clinicians in the treatment and rehabilitation of CP patients.     

The effects of fixed and articulated ankle-foot orthoses on gait patterns in subjects with cerebral palsy.

Twenty-one subjects with spastic diplegic cerebral palsy were studied to quantify the effects of fixed and articulated ankle-foot orthoses (AFOs) on gait and delineate criteria for their use. Children underwent gait analysis under three conditions, fixed AFOs (FAFOs), articulated AFOs (AAFOs), and shoes alone. Greater dorsiflexion occurred at initial contact with both FAFOs and AAFOs than shoes alone. Dorsiflexion at terminal stance was greatest in AAFOs. Plantarflexor power generation at preswing was preserved in AAFOs. No differences were found in knee position during stance. Knee-extensor strength was positively related to knee extension during stance. No relationships were found between dorsiflexion range of motion, calf spasticity and strength, and peak dorsiflexion during stance. AAFOs are appropriate for subjects with varying degrees of calf spasticity, as long as adequate passive range of motion is available. These findings can be applied primarily to children who do not have a preexisting tendency to crouch.