Kinetic Relationships between the Hip and Ankle Joints during Gait in Children with Cerebral Palsy: A Pilot Study

Abstract

[Purpose] The purpose of this study was to evaluate kinetic relationships between the ankle and hip joints during gait, in the late stance, in children with spastic cerebral palsy (CP). [Subjects] The subjects were 3 ambulant children with spastic hemiplegic CP (aged 10, 13, and 14: CP group) and 3 typically developing children with the same ages (control). [Methods] A three-dimensional gait analysis including force data was performed to compare the peak moment, power, and ankle/hip power ratio between the hemiplegic (uninvolved and hemiplegic) and the control groups. In the statistical analysis, mean values from 5 gait cycles for each of 3 conditions (uninvolved, hemiplegic and control) were used. The three conditions were compared by performing a Kruskal-Wallis test and Steel-Dwass multiple comparisons. [Results] The peak moments of ankle plantar flexors in the 10-year-old case, were significantly lower on the uninvolved and hemiplegic sides compared with the control group, respectively. The peak flexion moments of the hip on the hemiplegic side were significantly higher compared with the control in the 14- and 13-year-old cases. The peak of ankle power generation (A2) in the 13- and 10-year-old cases were significantly lower on the uninvolved and hemiplegic sides, respectively, compared with the control. The peaks of hip flexor power generation (H3) in the 14- and 13-year-old cases were significantly higher on the uninvolved and hemiplegic sides, respectively. The A2/H3 ratios were significantly lower on the uninvolved and hemiplegic sides compared with the control, and the ratio for the hemiplegic side was lower than that for the uninvolved side. [Conclusion] This study shows that propulsion of walking is generated by hip, rather than the ankle, on both the hemiplegic and involved sides.

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

“…A previous study by Moreira et al (2017) determined that Peak Hip Power (PHP) and PHP occurred in less than 68% of gait cycle time as sensitive indicators for decision making in Rectus Femoris Transfer surgery [ 20 ]. Another study by Ishihara and Higuchi (2014) formulated peak ankle power by peak hip power A2/H3 ratio based on graphs [ 14 ]. However, the present study noted the specific sub-phase in which the Peak Hip Power and Peak Ankle Power was appearing and had given quantitative values for easy comparison between pre and post-treatment kinetic parameters.…”

“…However, it is not clear how joint power and work are used in different phases of the gait cycle in a child with CP. Ishihara and Higuchi (2014) studied the peak hip flexor power generation in spastic hemiplegic and healthy children, however, the number of participants was small and did not include other types of CP [14]. Dohin and Salem (2015) studied the hip and ankle power generation 1-year post-SEMLS surgery, however, they did not compare their results with healthy children [15].…”

Elastic energy in locomotion: Spring-mass vs. poly-articulated models

“…Hence, the contribution of the different joints in the global stiffness could be estimated. Joint stiffness is also evoked as a key criterion in disabilities such as falls [26,27], balance management [28,29], and cerebral palsy [30]. The organization of local work or local stiffness to produce a global stiffness could be considered as a new criterion of motor behavior optimization useful for rehabilitation procedures, mechanical energy optimization, and prostheses/exoskeleton stiffness management.…”

Plantarflexor training affects propulsive force generation during gait in children with spastic hemiplegic cerebral palsy: a pilot study

“…Propulsive force generation at push-off during gait in children with spastic CP is dependent on the hip joint rather than the ankle joint 16 , 19 ) . In general, healthy individuals have a complementary relationship between the hip and ankle joints for propulsive force generation during gait 7 , 8 ) .…”

“…Power values were labelled according to the protocol of Eng et al 15 ) : H1 (hip extensor power generation during the early stance phase); H2 (hip joint power absorption); H3, (hip flexor power generation); A1, ankle plantarflexor power absorption; and A2 (ankle plantarflexor power generation). Furthermore, peak value of both joints and ankle-to-hip power ratio (A2/H3 ratio) 16 ) were calculated. The A2/H3 ratio represents the proportions of ankle plantarflexion and hip flexion during the push-off phase, with a higher ratio indicates a higher proportion of ankle involvement compared with that he the hip.…”