Jacqueline Romkes

Comparison of a dynamic and a hinged ankle–foot orthosis by gait analysis in patients with hemiplegic cerebral palsy

We studied the effect of a dynamic ankle-foot orthosis (d-AFO) on gait in 12 hemiplegic cerebral palsy patients. Sagittal plane kinematic and kinetic data of walking with the d-AFO were compared with walking barefoot, walking in a hinged ankle-foot orthosis (h-AFO) with a plantarflexion block and normal values. All patients had excessive plantarflexion and initial toe contact when walking barefoot. The d-AFO did not improve gait significantly whereas the h-AFO did. The benefits of controlling plantarflexion by a longer lever arm fror the h-AFO to the proximal calf included a heel-toe gait pattern, reduced plantarflexion, increased step and stride length and reduced power absorption.

Evaluating upper body movements during gait in healthy children and children with diplegic cerebral palsy.

Movements of the lower limbs during gait have been analysed extensively whereas data on upper body movements are scarce. The aim of this study was to evaluate upper body movements during gait in nine healthy children and 10 children with diplegic cerebral palsy. Children were investigated using a full-body marker set to calculate the upper body kinematics of trunk and arms. When the healthy children were compared with the children with cerebral palsy, the latter compensated more for their gait deviations and were less stable. This was expressed by their greater variability in arm movements and increased movements at the thorax. The thorax showed an increased forward tilt with greater range of motion over the gait cycle. The shoulders were more abducted with increased elbow flexion. Gait analysis with the full-body marker set has offered prospects for a better understanding of compensatory mechanisms for the pathological gait pattern in children with diplegic cerebral palsy.

Effects of plantarflexion on pelvis and lower limb kinematics

Modelling the effect of soleus and gastrocnemius contractions against the floor resistance in a forward dynamics simulation revealed that hip flexion, internal rotation and adduction together with external pelvic rotation could be attributed to a direct, but distant effect of triceps surae contraction. Knee flexion smoothed out the effect. To validate this clinically relevant biomechanical observation, ankle plantar flexion was correlated with hip and pelvic rotation retrospectively in children with spastic cerebral palsy. In 49 children with spastic hemiplegia, plantar flexion showed a significant correlation with increased pelvic retraction and hip internal rotation. In contrast, in 47 children with spastic diplegia no significant effect of the triceps surae on hip and pelvis kinematics was found. Bilateral hip and knee flexion in diplegia appeared to prevent the proximal effect of the triceps surae seen in the hemiplegics. In diplegia triceps surae overactivity did not appear to be a significant cause of internal rotation gait.

Tibialis anterior tendon shortening in combination with Achilles tendon lengthening in spastic equinus in cerebral palsy

Equinus is the commonest deformity in cerebral palsy (CP). Many different surgical procedures have been described for the treatment of spastic equinus. In long standing equinus deformities the tibialis anterior muscle becomes elongated which is one reason for muscle weakness. Surgical tendon shortening of the tibialis anterior tendon was therefore introduced to rebalance muscle strength. All patients with CP who had a tibialis anterior tendon shortening (TATS) in combination with a tendo Achilles lengthening (TAL) were included in this study. A total of 29 patients had 30 surgical interventions (21 hemiplegic patients: 14 boys/7 girls, age 9-22 years; mean 15.2 years; 5 diplegics and 3 quadriplegics; 5 boys/3 girls, age 7-37.5 years; mean 14.8 years). Fifteen patients had additional surgery (soft tissue or bony procedures). The TATS was performed at the distal insertion with transosseous tendon fixation in the medial cuneiform bone at the original place. Movement Analysis Profile (MAP) for ankle dorsi-/plantarflexion, Gait Profile Score (GPS), Gait Deviation Index (GDI), and Gillette Gait Index (GGI) improved significantly for all patients compared pre- to postoperatively. In 93% of the patients active dorsiflexion of the ankle was possible postoperatively. We conclude that TATS in combination with TAL in spastic equinus in CP is a safe procedure and improves but not completely corrects foot positioning during gait. For the treatment of spastic equinus in CP we recommend shortening of the elongated antagonist (TATS) in combination with lengthening of the short agonist (TAL) for achieving optimal postoperative function.

Hip abductor control in walking following stroke — the immediate effect of canes, taping and TheraTogs on gait

Objective: To confirm previous findings that hip abductor activity measured by electromyography (EMG) on the side contralateral to cane use is reduced during walking in stroke patients. To assess whether an orthosis (TheraTogs) or hip abductor taping increase hemiplegic hip abductor activity compared with activity during cane walking or while walking without aids. To investigate the effect of each condition on temporo-spatial gait parameters. Design: Randomized, within-participant experimental study. Setting: Gait laboratory. Subjects: Thirteen patients following first unilateral stroke. Intervention: Data collection over six gait cycles as subjects walked at self-selected speed during: baseline (without aids) and in randomized order with (1) hip abductor taping, (2) TheraTogs, (3) cane in non-hemiplegic hand. Main measures: Peak EMG of gluteus medius and tensor fascia lata and temporo-spatial gait parameters. Results: Cane use reduced EMG activity in gluteus medius from baseline by 21.86%. TheraTogs increased it by 16.47% (change cane use—TheraTogs P=0.001, effect size = -0.5) and tape by 5.8% (change cane use—tape P=0.001, effect size = -0.46). In tensor fascia lata cane use reduced EMG activity from baseline by 19.14%. TheraTogs also reduced EMG activity from baseline by 1.10% (change cane use—TheraTogs P=0.009, effect size -0.37) and tape by 3% (not significant). Gait speed (m/s) at: baseline 0.44, cane use 0.45, tape 0.48, TheraTogs 0.49. Conclusion: Hip abductor taping and TheraTogs increase hemiplegic hip abductor activity and gait speed during walking compared with baseline and cane use.

The influence of muscle strength on the gait profile score (GPS) across different patients.

BACKGROUND Muscle strength greatly influences gait kinematics. The question was whether this association is similar in different diseases. METHODS Data from instrumented gait analysis of 716 patients were retrospectively assessed. The effect of muscle strength on gait deviations, namely the gait profile score (GPS) was evaluated by means of generalised least square models. This was executed for seven different patient groups. The groups were formed according to the type of disease: orthopaedic/neurologic, uni-/bilateral affection, and flaccid/spastic muscles. RESULTS Muscle strength had a negative effect on GPS values, which did not significantly differ amongst the different patient groups. However, an offset of the GPS regression line was found, which was mostly dependent on the basic disease. Surprisingly, spastic patients, who have reduced strength and additionally spasticity in clinical examination, and flaccid neurologic patients showed the same offset. Patients with additional lack of trunk control (Tetraplegia) showed the largest offset. CONCLUSION Gait kinematics grossly depend on muscle strength. This was seen in patients with very different pathologies. Nevertheless, optimal correction of biomechanics and muscle strength may still not lead to a normal gait, especially in that of neurologic patients. The basic disease itself has an additional effect on gait deviations expressed as a GPS-offset of the linear regression line.

Torsionsfehler an den unteren Extremitäten bei Patienten mit infantiler Zerebralparese

ZusammenfassungBei Patienten mit infantiler spastischer Zerebralparese entwickeln sich oft Torsionsfehler an Hüfte, Unterschenkel oder Fuß. Ein Faktor, der zu diesen Deformitäten führt, wird in der abnormalen Muskelaktivität mit gesteigertem Tonus und Spastizität gesehen. In der vorliegenden Arbeit konnte ganganalytisch im Vergleich von 13 Patienten mit ICP und 8 Normalpersonen ein statistisch signifikanter Unterschied der Torsionsmomente an Hüfte, Knie und Sprunggelenk nachgewiesen werden.Die Patienten gingen spitzfüßig, mit einwärts gestellten Füßen und innenrotierten Hüften, die Normalpersonen im Fersenballengang. An der Hüfte bestand bei Normalpersonen in der ersten Hälfte der Standphase ein Innentorsionsmoment, das in der Mitte in ein Außentorsionsmoment wechselte. Bei den Patienten war der Verlauf umgekehrt. An Knie- und Sprunggelenk war das Innentorsionsmoment vermindert. Die veränderten Drehmomente können durch die vorhanden Torsionsfehler bedingt sein, oder aber auch diese erklären. Da sich das Skelett an die einwirkende Kraft anpasst, können die abnormen Torsionskräfte als ein deformierender Faktor angesehen werden.Für eine effiziente Prophylaxe wird ein physiologischer Fersenballengang postuliert. Bestehende Deformitäten am Unterschenkel können nur operativ durch eine Osteotomie korrigiert werden. Am Hüftgelenk setzt sich die Torsionsdeformität aus einer funktionellen und einer ossären Komponente zusammen. Physiotherapie und Weichteileingriffe an M. tensor fasciae latae und ventralen Anteilen der Mm. glutaei können den funktionellen Anteil beeinflussen, zur Korrektur der verstärkten Antetorsion ist eine intertrochantäre Derotationsosteotomie erforderlich. Da die Patienten neben Gleichgewichtsstörungen eine ungenügende Kontrolle über ihre Beine aufweisen, muss bei der Korrektur der Innentorsion an der Hüfte eine leichte Restinnentorsion belassen.AbstractPatients with spastic cerebral palsy often develop torsional deformities at the level of hip, shank or foot. The abnormal muscle activity such as spasticity or the increase of tone are considered as the major cause. The present study shows that the gait pattern is another cause which may lead to deformities. The study is based on gait analysis of 13 patients and 8 normal controls. The major and significant differences in gait kinematics were toe walking, toeing-in and internal rotation at the hip in the patients whereas the unaffected control group had a physiological heel–toe gait.The difference in torsional moments at the hip, knee and ankle were statistically significant. At the knee and the ankle a decrease in the internal rotation moment was found, whereas at the hip a paradoxical curve pattern with a more externally directed rotation moment was seen. These differences in torsional moments can explain the external rotation at the foot and/or shank as well as the increase in femoral anteversion, although they might be primarily caused by the deformity itself. Because a constantly acting force, however, changes the bony form and/or shape, the abnormal moments can be considered as a factor leading to deformities.A heel–toe gait seems to be mandatory for an efficient prophylaxis. Torsional deformities at the shank require a corrective osteotomy which is performed at the supramalleolar site and fixed by an unilateral, external fixator. Malrotations at the hip usually show two components: the functional part can be corrected by lengthening and weakening the tensor fasciae latae and the ventral parts of the glutei, using stretching exercises, botulinum toxin A or operative lengthening and releases. The increased femoral anteversion needs to be corrected by a femoral derotation osteotomy.Patients with cerebral palsy show a reduced control of their legs; therefore, balance internal torsion should not be corrected to neutral and overcorrection must be avoided. A remaining slight internal rotation after correction will help to spontaneously stabilize the leg if it gives way at initial contact, by “falling underneath the centre of gravity”. If the leg is in neutral or external rotation, the patient needs to realign the centre of gravity over the dynamically unstable leg, showing a trunk-lean over the leg, the Duchenne limp.

Using Skin Markers for Spinal Curvature Quantification in Main Thoracic Adolescent Idiopathic Scoliosis: An Explorative Radiographic Study.

Background and Purpose Although the relevance of understanding spinal kinematics during functional activities in patients with complex spinal deformities is undisputed among researchers and clinicians, evidence using skin marker-based motion capture systems is still limited to a handful of studies, mostly conducted on healthy subjects and using non-validated marker configurations. The current study therefore aimed to explore the validity of a previously developed enhanced trunk marker set for the static measurement of spinal curvature angles in patients with main thoracic adolescent idiopathic scoliosis. In addition, the impact of inaccurate marker placement on curvature angle calculation was investigated. Methods Ten patients (Cobb angle: 44.4±17.7 degrees) were equipped with radio-opaque markers on selected spinous processes and underwent a standard biplanar radiographic examination. Subsequently, radio-opaque markers were replaced with retro-reflective markers and the patients were measured statically using a Vicon motion capture system. Thoracolumbar / lumbar and thoracic curvature angles in the sagittal and frontal planes were calculated based on the centers of area of the vertebral bodies and radio-opaque markers as well as the three-dimensional position of the retro-reflective markers. To investigate curvature angle estimation accuracy, linear regression analyses among the respective parameters were used. The impact of inaccurate marker placement was explored using linear regression analyses among the radio-opaque marker- and spinous process-derived curvature angles. Results and Discussion The results demonstrate that curvatures angles in the sagittal plane can be measured with reasonable accuracy, whereas in the frontal plane, angles were systematically underestimated, mainly due to the positional and structural deformities of the scoliotic vertebrae. Inaccuracy of marker placement had a greater impact on thoracolumbar / lumbar than thoracic curvature angles. It is suggested that spinal curvature measurements are included in marker-based clinical gait analysis protocols in order to enable a deeper understanding of the biomechanical behavior of the healthy and pathological spine in dynamic situations as well as to comprehensively evaluate treatment effects.

Automatic selection of a representative trial from multiple measurements using Principle Component Analysis

Experimental data in human movement science commonly consist of repeated measurements under comparable conditions. One can face the question how to identify a single trial, a set of trials, or erroneous trials from the entire data set. This study presents and evaluates a Selection Method for a Representative Trial (SMaRT) based on the Principal Component Analysis. SMaRT was tested on 1841 data sets containing 11 joint angle curves of gait analysis. The automatically detected characteristic trials were compared with the choice of three independent experts. SMaRT required 1.4s to analyse 100 data sets consisting of 8±3 trials each. The robustness against outliers reached 98.8% (standard visual control). We conclude that SMaRT is a powerful tool to determine a representative, uncontaminated trial in movement analysis data sets with multiple parameters.

The association between premature plantarflexor muscle activity, muscle strength, and equinus gait in patients with various pathologies.

This study provides an overview on the association between premature plantarflexor muscle activity (PPF), muscle strength, and equinus gait in patients with various pathologies. The purpose was to evaluate whether muscular weakness and biomechanical alterations are aetiological factors for PPF during walking, independent of the underlying pathology. In a retrospective design, 716 patients from our clinical database with 46 different pathologies (orthopaedic and neurologic) were evaluated. Gait analysis data of the patients included kinematics, kinetics, electromyographic activity (EMG) data, and manual muscle strength testing. All patients were clustered three times. First, patients were grouped according to their primary pathology. Second, all patients were again clustered, this time according to their impaired joints. Third, groups of patients with normal EMG or PPF, and equinus or normal foot contact were formed to evaluate the association between PPF and equinus gait. The patient groups derived by the first two cluster methods were further subdivided into patients with normal or reduced muscle strength. Additionally, the phi correlation coefficient was calculated between PPF and equinus gait. Independent of the clustering, PPF was present in all patient groups. Weak patients revealed PPF more frequently. The correlations of PPF and equinus gait were lower than expected, due to patients with normal EMG during loading response and equinus. These patients, however, showed higher gastrocnemius activity prior to foot strike together with lower peak tibialis anterior muscle activity in loading response. Patients with PPF and a normal foot contact possibly apply the plantarflexion-knee extension couple during loading response. While increased gastrocnemius activity around foot strike seems essential for equinus gait, premature gastrocnemius activity does not necessarily produce an equinus gait. We conclude that premature gastrocnemius activity is strongly associated with muscle weakness. It helps to control the knee joint under load independent from the underlying disease, and it is therefore a secondary deviation. If treated as primary target, caution should be exercised.