J Korean Orthop Assoc.  2011 Apr;46(2):130-139.

Changes of the Muscle-tendon Lengths in a Three-dimensional Musculoskeletal Model according to the Hip Transverse Angle in Cerebral Palsy Patients with Crouch Gait

• Kim JY
• Kim HW
• Lee KS
• Hahn SB
• Park HW
• Park KB

Abstract

PURPOSE
Crouch gait is one of the common pathologic gaits in children with cerebral palsy. Hamstring lengthening for alleviation of knee flexion is often considered as a first choice for the treatment of crouch gait. However, there have been a variety of reports about the lengths of the hamstring muscle. The purpose of this study was to classify the crouch gait on the transverse plane and to suggest a guide line for hamstring lengthening by analyzing the length of these muscles.
MATERIALS AND METHODS
The subjects for this study were selected in ambulatory spastic diplegia patients with crouch gait. A total of sixty-two patients (124 cases) were included. The gait parameters and the muscle lengths were compared. The range of +/-1 standard deviation of the normal middle stance hip rotation was considered as the normal range. The subjects were divided into three groups as hip external rotated (group I), normal (group II) and hip internal rotated (group III) according to the hip rotation.
RESULTS
The flexion of the knee and hip was the greatest in group III and dorsiflexion of the ankle was the least in group I. On comparison of moment and power on the sagittal plane, there was no significant difference among the groups. In group III, the percent lengths of the adductor, biceps femoris and gracilis muscles were increased the most, whereas the percent length of the semimembranosus was decreased the most. There was no statistical difference between groups I and II and the normal control group.
CONCLUSION
Irrespective of the hip rotation, the length of the hamstring muscle in patients with crouch gait did not differ compared to that of the normal control. But if rotational osteotomy is done for the correction of the increased femoral anteversion in group III, then we should consider lengthening the semimembranosus muscle.

Keyword

cerebral palsy; crouch gait; musculoskeletal model; hip rotation

MeSH Terms

Animals
Ankle
Cerebral Palsy
Child
Gait
Hip
Humans
Knee
Muscles
Osteotomy
Reference Values

Figure

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  Figure 1 Sagittal and transverse kinematics during gait. The flexion of knee during midstance and internal rotation of hip are more increased in group III compared to the other groups. Patients in group III show more severe crouch and internal rotating gait. The two thin solid lines represent the normal ranges.

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  Figure 2 Percent muscle lengths during gait cycle. In group III, percent lengths of adductor, biceps femoris and gracilis muscle are increased and percent length of semimembranosus is decreased compared to the other groups during midstance phase. However there are no statistical differences between these groups and normal control. The two thin solid lines represent the normal ranges.

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