Functional donor-site morbidity during level and uphill gait after a gastrocnemius or soleus muscle-flap procedure

Background: There is only limited objective information about functional donor-site morbidity after harvest of one head of the triceps surae muscles to cover a severe soft-tissue defect of the leg. The purpose of the present study was to investigate whether a functional deficit is present during level and uphill walking after such a procedure. Methods: Five subjects who had completely recovered from the initial injury were studied with use of comprehensive gait analysis during free level, fast level, and uphill walking on a ramp at a 10 degrees inclination. Results: Gait analysis revealed no relevant donor-site morbidity affecting level gait at a free walking speed (mean, 1.27 m/sec; range, 1.18 to 1.40 m/sec). When the subjects walked at a higher velocity (mean, 1.89 m/sec; range, 1.58 to 2.43 m/sec), an asymmetry of the ground-reaction forces was seen. The second vertical peak force during push-off was reduced by a mean of 7.3% (range, 0.94% to 12.24%), and the impulse in the direction of progression was reduced by a mean of 8.7% (range, 0.13% to 17.87%) on the affected side (p = 0.04). During uphill walking, a compensatory strategy to reduce the demand on the posterior calf muscles was seen in all subjects-that is, they shortened the length of the step on the contralateral side by a mean of 3.9 cm (range, 2.2 to 6.2 cm), which corresponded to a mean side-to-side difference of 5.6% (range, 2.18% to 6.18%) (p = 0.04). A cal caneal motion pattern, denoted as increased ankle dorsiflexion, was seen in three of the five subjects during uphill walking as a sign of decreased function of the posterior calf muscles. Two of them (both with a soleus flap) also had a calcaneal pattern during fast gait. Conclusions: We concluded from this study that the functional donor-site morbidity after harvest of one head of the triceps surae muscles is mild in subjects who have had a complete recovery from their initial injury. Normal level gait is possible. However, deficits are seen in more demanding tasks such as fast walking or uphill walking.