J Korean Orthop Assoc.  2009 Apr;44(2):170-179.

Changes in the Gastrocnemius and Soleus Muscle Length during Gait in CP Patients with an Equinus Deformity

• Kim H
• Ahn JH
• Lee HH
• Koo JY
• Yee HC
• Choy WS

Abstract

PURPOSE
To measure the muscle length of the gastrocnemius and soleus during gait in CP patients with an equinus deformity before and after surgery. MATERIALS AND METHODS: Twelve CP patients with an equinus deformity (17 limbs) were examined by gait analysis preoperatively and postoperatively. The patient group was further classified into the TAL and Strayer group according to the surgical technique. The mean age and mean follow-up periods were 14.3 years (5-25 years) and 15.3 months (12.5-18.5 months), respectively. The muscle length of the Gastrocnemius and Soleus was measured during gait using the SIMM program linked to a gait analysis system. RESULTS: The ankle ROM, knee ROM, maximal muscle length and peak-to-peak excursion during gait improved after surgery. There was a significant difference between the preoperative and postoperative measurements (p<0.05), but no difference between the postoperative and control groups (p>0.05). The muscle length of the soleus was elongated during gait after the Strayer procedure. CONCLUSION: Patients with an equinus deformity had a contracted triceps muscle, which was elongated after surgery. These changes were quantified by a comparison of the preoperative and postoperative measurements.

Keyword

Cerebral palsy; Equinus deformity; TAL; Strayer; Gait analysis

MeSH Terms

Animals
Ankle
Cerebral Palsy
Contracts
Equinus Deformity
Follow-Up Studies
Gait
Humans
Knee
Muscle, Skeletal
Muscles

Figure

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  Fig. 1 Muscle modeling using SIMM. Muscle model was made for the lateral head of gastrocnemius (LGAS), medial head of gastrocnemius (MGAS), and soleus (SOL). The changes of muscle lengths during gait were measured with these muscle models.

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  Fig. 2 Ankle and knee kinematic curve and points (a1-a5) at which the muscle length was measured.

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  Fig. 3 The changes of ankle and knee kinematics after the operation in Strayer and TAL group.

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  Fig. 4 The changes of muscle length during gait in control group.

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  Fig. 5 The changes of muscle length during gait in patient group at preoperative and postoperative gait analysis.

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  Fig. 6 Schematic relationships of gastrocnemius and soleus muscle after Strayer procedure.

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