Stiff-knee gait in cerebral palsy: how do patients adapt to uneven ground?

Patients with cerebral palsy frequently experience foot dragging and tripping during walking due to reduced toe clearance mostly caused by a lack of adequate knee flexion in swing (stiff-knee gait). The aim of this study was to investigate adaptive mechanism to an uneven surface in stiff-knee walkers with cerebral palsy. Sixteen patients with bilateral cerebral palsy, GMFCS I-II and stiff-knee gait, mean age 14.1 (SD=6.2) years, were compared to 13 healthy controls with mean age 13.5 (SD=4.8) years. Gait analysis including EMG was performed under even and uneven surface conditions. Similar strategies to improve leg clearance were found in patients as well as in controls. Both adapted with significantly reduced speed and cadence, increased outward foot rotation, knee and hip flexion as well as anterior pelvic tilt. Therefore cerebral palsy and stiff-knee gait did not affect the adaptation capacity on the uneven surface. On the uneven surface an average increase in knee flexion of 7° (SD=3°) and 12° (SD=5°) was observed in controls and patients with cerebral palsy, respectively. Although rectus femoris activity was increased in patients with cerebral palsy, they were able to increase their knee flexion during swing. The results of this study suggest that walking on uneven surface has the potential to improve knee flexion in stiff-knee walkers. Therefore training on uneven surface could be used as a conservative treatment regime alone, in combination with Botulinum neurotoxin or in the rehabilitation of surgery.

Böhm H ，Hösl M ，Schwameder H ，Döderlein L ... -  《-》

Performance of stair negotiation in patients with cerebral palsy and stiff knee gait.

Due to the limited knee range of motion, achieving adequate foot clearance while walking on level ground constitutes a major problem for patients with cerebral palsy and stiff knee gait. Stair negotiation as an activity of daily life requires a considerably higher knee range of motion than level ground walking, but little is known yet as to whether such patients are able to walk stairs. The aim of this study was to investigate how patients with a limited knee range of motion negotiate stairs. Do they increase their peak knee flexion and use the same pattern as in walking on level ground? How do the muscles act during stair negotiation? In this explorative study, 17 adults with bilateral, spastic cerebral palsy and stiff knee gait and 25 healthy subjects were examined. 3D motion analysis, including electromyography, was performed while walking on level ground, upstairs, and downstairs. A linear mixed model was used for between- and within-group comparisons. Walking upstairs and downstairs, patients increased their peak knee flexion by around 30° compared to level walking. Thus, increased knee flexion may be seen as the main mechanism for maintaining foot clearance on stairs. An increased pelvic obliquity (elevation) and hip flexion were also found and involved subjects showed a slight increase in rectus femoris activity when walking on stairs compared to level walking within the phases of high knee flexion. This study showed that patients with cerebral palsy and stiff knee gait are able to flex their knees more than would be required for level walking. Hence, the patients are able to adapt their rectus activity to stair walking to some extent. Therefore, further investigations might help to open up new therapeutic options to facilitate level walking and stair negotiation in patients with stiff knee gait.

Lewerenz A ，Wolf SI ，Dreher T ，Krautwurst BK ... -  《-》

Rectus Femoris Transfer Versus Rectus Intramuscular Lengthening for the Treatment of Stiff Knee Gait in Children With Cerebral Palsy.

Ellington MD ，Scott AC ，Linton J ，Sullivan E ，Barnes D ... -  《-》

Which functional impairments are the main contributors to pelvic anterior tilt during gait in individuals with cerebral palsy?

While past investigations focused on describing pelvic motion patterns in the frontal and transversal plane, the sagittal plane "double bump" pattern commonly found in children with cerebral palsy was only rarely investigated, especially concerning the underlying pathology. 375 ambulatory (GMFCS I-III) patients with bilateral spastic cerebral palsy were included in this study. Gait and clinical data (ROM, strength, spasticity) were classified in two different ways: (a) into two groups of normal and enhanced mean anterior pelvic tilt and (b) into two groups of moderate and excessive ROM in pelvic tilt. The results reveal that increased mean pelvic tilt is mainly associated with gait features of reduced hip extension and increased pelvic and trunk obliquity ROM but with increased knee ROM. In the clinical exam this corresponds to a smaller passive knee extension deficit and reduced knee flexor strength. It seems that flexors to extensors strength imbalance at the knee is a major feature why mean pelvic position is tilted anterior whereas maximum passive hip extension is of minor importance. Contrarily, excessive sagittal pelvic ROM is associated with increased knee flexion at initial contact and reduced knee ROM. Furthermore, Duncan-Ely- and Tardieu-tests show both increased values in this group with excessive pelvic range of motion indicating for spastic rectus femoris activation. The results of our study indicate that the two gait variables are influenced by different specific mechanisms which are now described for the first time. Since the pelvis plays a central role during gait, these findings should be considered when planning single event multilevel surgery in patients with cerebral palsy.

Wolf SI ，Mikut R ，Kranzl A ，Dreher T ... -  《-》

Does muscle coactivation influence joint excursions during gait in children with and without hemiplegic cerebral palsy? Relationship between muscle coactivation and joint kinematics.

The theoretical role of muscle coactivation is to stiffen joints. The aim of this study was to assess the relationship between muscle coactivation and joint excursions during gait in children with and without hemiplegic cerebral palsy. Twelve children with hemiplegic cerebral palsy and twelve typically developing children underwent gait analysis at three different gait speeds. Sagittal hip, knee, and ankle kinematics were divided into their main components corresponding to joint excursions. A coactivation index was calculated for each excursion from the electromyographic envelopes of the rectus femoris/semitendinosus, vastus medialis/semitendinosus, or tibialis anterior/soleus muscles. Mixed linear analyses of covariance modeled joint excursions as a function of the coactivation index and limb. In typically developing children, increased coactivation was associated with reduced joint excursion for 8 of the 14 linear models (hip flexion, knee loading, knee extension in stance, knee flexion in swing, ankle plantarflexion from initial contact to foot-flat, ankle dorsiflexion in stance and in swing). Conversely, ankle plantarflexion excursion at push-off increased with increasing tibialis anterior/soleus coactivation. In the involved limbs of the children with cerebral palsy, knee loading, ankle plantarflexion at push off, and ankle dorsiflexion in swing decreased, while hip extension increased, with increasing muscle coactivation. The relationships between muscle coactivation and joint excursion were not equally distributed in both groups, and predominant in typically developing children. The results suggest that excessive muscle coactivation is not a cause of stiff-knee gait in children with hemiplegic cerebral palsy, but appears to be related to spastic drop foot.

Gross R ，Leboeuf F ，Hardouin JB ，Perrouin-Verbe B ，Brochard S ，Rémy-Néris O ... -  《-》