Patricia Van De Walle

Reliability of head and trunk kinematics during gait in children with spastic diplegia

This study describes the reliability of a clinically oriented model for three-dimensional movement analysis of head and trunk movements in children with spastic diplegia. The model consists of five rigid segments (head, thorax, pelvis, shoulder line, spine) and includes a detailed analysis of spinal segmental movements. Within and between session reliability during gait was tested in 10 children with spastic diplegia (6-14yrs). Reliability of discrete parameters was assessed with the intraclass correlation coefficient (ICC) and similarity of thorax and pelvis waveforms with the coefficient of multiple correlation (CMC). Measurement errors were calculated for all parameters (SEM, σ). Results indicated acceptable within and between session reliability of discrete parameters for thorax, pelvis, shoulder line, angle of kyphosis and the majority of the spinal segmental angles, reflected by low SEMs (<4°) and most ICCs>0.60. Within and between session waveform errors were below 4°. CMCs ranged from poor to very good, with highest values for movements in the frontal and transversal planes. The angle of lordosis showed lower between session reliability for several discrete parameters, although waveform errors were still below 5°. Head parameters showed lower overall reliability. The results of this study support the reliability of the proposed model. Head kinematic parameters should be interpreted with caution, due to difficulties in standardization. Accurate palpation of the spinal markers, especially the lumbar spine, is critical and demands thorough training of the assessor.

Age-related differences in muscle activity patterns during walking in healthy individuals

OBJECTIVE To examine how muscle activity over the entire gait cycle changes with increasing age. METHODS Electromyography data of the erector spinae, rectus femoris, vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius muscles were collected by an instrumented gait analysis during over ground walking in healthy adults aged between 20 and 89 years. Participants were categorized per decade (n = 105, 15 per decade, decades 3-9). Normalized integrated linear envelopes of the electromyographic signal were calculated for one stride. A one way ANOVA using spm1d statistics explored the differences between age groups, followed by a post hoc analysis. RESULTS While initiation of decline commenced at the age of 60 for erector spinae and tibialis anterior, age-related changes are most pronounced after the age of 80. Concerning timing of muscle activity, subjects in decade 7-9 had prolonged activity and/or early activity of the erector spinae, vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius compared to other decades. Regarding amplitude of muscle activity, decreased peak amplitudes of the erector spinae, rectus femoris, vastus lateralis and gastrocnemius were observed in decades 7-9 compared to other decades. CONCLUSION Both timing and amplitude of muscle activation patterns need to be considered to understand the aging process. Regarding the erector spinae, tibialis anterior and vastus lateralis, a decrease in muscle activation coincides with prolonged activity, compared to the gastrocnemius where decreased muscle activation is associated with early activation.

Age-related changes in arm motion during typical gait

BACKGROUND When toddlers learn to walk, they do so with a typical high guard position of the arms. As gait matures, children develop a reciprocal arm swing. So far, there have been no attempts to describe age-related changes of arm movements during walking after this first rapid development. RESEARCH QUESTION The purpose of this study was to investigate age-related changes in arm movement during typical gait. METHODS All participants (n = 102) received gait analysis using a full-body marker set (Plug-in Gait). Participants were divided into five age-groups: young children (G1: n = 20; 3.0-5.9y), children (G2: n = 24; 6.0-9.9y), pubertal children (G3: n = 26; 10.0-13.9y), adolescents (G4: n = 16; 14.0-18.9y) and adults (G5: n = 16; 19.0-35.2y). Age-related changes in arm movements were investigated by comparing continuous joint angular waveforms (spm1d) between all groups, as well as by comparing the mean joint angle and range of motion of the different joints between age-groups. RESULTS The overall shape of movement patterns was comparable across all age groups. Nevertheless, with advancing age, consistency increased. At the shoulder, G1&2 showed a larger mean extension angle compared to older children and adults. The range of shoulder axial rotation was significantly larger in adults compared to all other age groups. In the youngest groups (G1-G2), an increased mean elbow flexion and mean wrist extension angle was found. SIGNIFICANCE Determining an exact age of maturation of arm swing remains difficult as parameter specific adult-like values were not reached at the same age but should not be set before the age of ten to fourteen years for any parameter.