Ernst B. Zwick

Intrasubject repeatability of gait analysis data in normal and spastic children

OBJECTIVE To evaluate intrasubject repeatability of data obtained from computer-aided motion analysis in normal and spastic children. DESIGN Prospective controlled study. BACKGROUND Information from gait analysis is used in selecting therapeutic interventions for gait improvement in cerebral palsy. While there are several studies regarding repeatability of normal gait, there are no studies evaluating the repeatability of spastic gait. METHODS Forty children (20 normal, 20 with diplegic type of cerebral palsy) were subjected to gait analysis. Kinematic, kinetic and time distance parameters obtained from gait analysis were studied for intrasubject variability within-day and between-day using statistical measures. RESULTS Normal children had lower variability in time distance parameters than spastic children both within and between days. The repeatability of kinetics was better than those of kinematics, and values for normal children were better than those for spastic children. Within-day repeatability of kinematics and kinetics was better in normal children. Between-day repeatability of kinematics was better in normal children, while spastic children showed better repeatability for kinetics. CONCLUSIONS We found lower repeatability of gait analysis data in spastic children compared to normal children. Restricted joint range of motion due to spasticity in the group of cerebral palsy patients may be responsible for the lower repeatability of data. Some errors due to marker placement are inadvertent and contribute to the lower between-day repeatability. RELEVANCE The results of this study should be of interest to clinicians who make therapeutic decisions in patients with cerebral palsy using gait analysis data, and for scientists studying normal and pathological gait.

Phenotypes of the N88S Berardinelli–Seip congenital lipodystrophy 2 mutation

Recently, two missense mutations (N88S, S90L) in the Berardinelli–Seip congenital lipodystrophy gene have been identified in autosomal dominant distal hereditary motor neuropathy and Silver syndrome. We report the phenotypic consequences of the N88S mutation in 90 patients of 1 large Austrian family and two unrelated German families. Variation in the clinical and electrophysiological phenotype enabled us to distinguish six subtypes. In 4.4%, the disorder was not penetrant. Twenty percent of the patients were subclinically affected; some of these patients could only be detected by pathological nerve conduction studies. A distal hereditary motor neuropathy type V phenotype characterized by predominant hand muscle involvement was found in 31.1%, whereas 14.5% showed typical Silver syndrome with amyotrophy of the small hand muscles and spasticity of the lower extremities. Moreover, the phenotype present in 20% was compatible with Charcot–Marie–Tooth disease. In 10%, the clinical diagnosis of pure or complicated hereditary spastic paraparesis was made. Electrophysiological studies showed an axonal neuropathy but also chronodispersion of compound motor action potentials and conduction blocks. Sensory nerve conduction studies were rarely pathological. Our study indicates that the dominant N88S mutation in the Berardinelli–Seip congenital lipodystrophy gene 2 leads to a broad spectrum of motor neuron disorders. Ann Neurol 2005;57:415–424

The Baumann procedure for fixed contracture of the gastrosoleus in cerebral palsy: EVALUATION OF FUNCTION OF THE ANKLE AFTER MULTILEVEL SURGERY

We treated 22 children (28 limbs) with diplegic cerebral palsy who were able to walk by the Baumann procedure for correction of fixed contracture of the gastrosoleus as part of multilevel single-stage surgery to improve gait. The function of the ankle was assessed by clinical examination and gait analysis before and at two years (2.1 to 4.0) after operation. At follow-up the ankle showed an increase in dorsiflexion at initial contact, in single stance and in the swing phase. There was an increase in dorsiflexion at initial push-off without a decrease in the range of movement of the ankle, and a significant improvement in the maximum flexor moment in the ankle in the second half of single stance. There was also a change from abnormal generation of energy in mid-stance to the normal pattern of energy absorption. Positive work during push-off was significantly increased. Lengthening of the gastrocnemius fascia by the Baumann procedure improved the function of the ankle significantly, and did not result in weakening of the triceps surae. We discuss the anatomical and mechanical merits of the procedure.

Effect of derotation osteotomy of the femur on hip and pelvis rotations in hemiplegic and diplegic children.

The purpose of this study was to evaluate hip and pelvis rotations in groups of hemiplegic and diplegic children before and after surgical correction of fixed internal rotation deformity of the hip. Twenty-two children with cerebral palsy (eight diplegia, 14 hemiplegia) having fixed internal rotation deformity at the hip were treated by multilevel surgery which included derotation osteotomy of the femur. Evaluation was done before and at a mean of 3.1 years after surgery using three-dimensional computerized gait analysis. Preoperatively, the patients in the hemiplegia group had a significantly greater compensatory external rotation of the pelvis than those in the diplegic group. Post-operatively there were no significant differences between the two groups. In the hemiplegia group the external rotation of the pelvis was corrected after correction of hip rotation by derotation osteotomy. Patients in the diplegia group showed significant improvements in the hip rotation with no significant change in the pelvis rotation after multilevel surgery.

Medial hamstring lengthening in the presence of hip flexor tightness in spastic diplegia

This study evaluated the effects of medial hamstring lengthening on gait in patients with diplegic cerebral palsy. A group of patients who underwent medial hamstring lengthening and distal rectus transfer was compared to a group of patients who underwent intramuscular psoas lengthening as well. Patients who underwent a psoas lengthening showed an increased anterior pelvic tilt and a tendency towards genu recurvatum, features that could indicate postoperative hamstring weakness. These results underline the importance of medial hamstrings for pelvis and knee motion in the sagittal plane during walking. In additional the limitations of the popliteal angle as a clinical measure to evaluate hamstring length in the presence of hip flexor tightness are discussed.

Gait Analysis in Patients With Parkinson's Disease Off Dopaminergic Therapy

OBJECTIVE To compare time-distance, kinematic, and kinetic gait parameters in patients with idiopathic Parkinsons disease (PD) off dopaminergic therapy with a group of healthy control subjects. DESIGN A group-comparison study. SETTING Gait analysis laboratory. PARTICIPANTS Patients with PD (n=20) and healthy age-matched controls (n=20). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Time-distance, kinematic, and kinetic gait variables. RESULTS PD patients walked slower with shorter stride-length, comparable cadence, and longer double support times. Kinematics showed a reduction of the range of motion in the hip, knee, and ankle joints. Maximum hip extension and the ankle plantar flexion were significantly reduced. Kinetic gait parameters showed reduced push-off ankle power and lift-off hip power generation. Strong correlations between these important body advancement mechanisms and the walking velocity were observed. CONCLUSIONS In addition to previously described dysfunctional kinematics, abnormal kinetic parameters play an important role in the characterization of gait in PD patients off therapy. Hence, these parameters could be used to document treatment effects of parkinsonian gait disorders.

The influence of age at single-event multilevel surgery on outcome in children with cerebral palsy who walk with flexed knee gait.

Aim  Information on the timing and long‐term outcome of single‐event multilevel surgery in children with bilateral spastic cerebral palsy (CP) walking with flexed knee gait is limited. Based on our clinical experience, we hypothesized that older children with bilateral spastic CP would benefit more from single‐event multilevel surgery than younger children. Moreover, any improvement in older children could be maintained with fewer additional surgery events.

Propulsive function during gait in diplegic children: evaluation after surgery for gait improvement.

Seventeen patients with diplegic cerebral palsy were assessed by clinical examination and three-dimensional gait analysis before and after surgery to improve gait. Selection of surgical procedures was according to a fixed set of selection criteria. The average postoperative follow-up was 3.8 years (range, 2.6-5.7 years). Clinical examination revealed an improved range of motion for the ankle and no reduction in the power grade at the hip, knee and ankle after surgery. Kinematic parameters showed improved knee extension in stance and significant changes towards a normal ankle motion pattern postoperatively. Kinetic evaluation demonstrated that most of the total power during walking was generated at the hip, with the ankle contributing a small part. After surgery, patients walked faster with an increased power generation at the hip during first double support and at the ankle during push off. Power generation at the hip in stance is pointed out to be an important mechanism for propulsion during walking.

Complex foot deformities associated with soft-tissue scarring in children

Two cases of deformities in scarred feet are presented. One case had an old, well healed forefoot amputation with severe equinovarus deformity, and the other had an equinus deformity following a burn injury 10 months prior. Both the cases were managed by primary release of the contracted joint capsules. The correction of the soft-tissue contractures was achieved by gradual distraction using the Ilizarov apparatus. The clinical presentation and surgical treatment of complex foot deformities, complicated by the presence of scar tissue, are presented. These cases illustrate the benefits of combining soft-tissue release with the Ilizarov technique of distraction histogenesis in the treatment of complicated foot deformities associated with scarring in pediatric patients.

Hip locomotion mechanisms in cerebral palsy crouch gait

The purpose of this study was to evaluate three defined locomotion patterns in cerebral palsy gait using computerised gait analysis. Ambulant diplegic children who had no previous surgery were included in the study and were divided into two groups: one group consisted of children having a crouch gait, and the other group did not have the crouch pattern of gait. An age-matched group of normal children served as the control group. Locomotion patterns studied were the hip hike, propulsive function of the hip extensors, and pseudo-adduction. A statistical analysis was performed between the groups, using defined parameters. The mechanism of hip hike was not utilised by any of the groups. Both groups of diplegic children showed power generation at the hip beginning in the first double support phase of the gait cycle and continuing in the first half of single limb support, while in the normals this was only in the first half of single limb support. Both the groups of diplegic children showed significantly more internal rotation in the first half of stance as compared to the group of normal children; the degree of hip adduction was the same in all the groups. Thus diplegic children had pseudo-adduction.