Characteristics of Lower Limb Muscle Activity During Walking and Stair Climbing With Full Weight Bearing in Postoperative Ankle Fracture Patients.

Background Ankle fractures are among the most common lower limb fractures. Following surgery, the ankle is immobilized in a splint or cast for a specific period. Even after full weight bearing is allowed, daily activities, such as walking and stair climbing, may be affected by residual pain, limited joint range of motion (ROM), and muscle weakness. The present study aimed to investigate lower limb muscle activity during walking and stair climbing in patients capable of unassisted ambulation after ankle fracture surgery. Methods The study included 18 patients who underwent open osteosynthesis for unilateral ankle fractures at our hospital, and 18 healthy volunteers with no history of lower limb fractures as a control group. The mean age of the postoperative ankle fracture patients was 59.0 ± 12.4 years, compared to 62.7 ± 12.0 years for the healthy volunteers. The mean time between surgery and this measurement for ankle fracture patients was 72.7 ± 27.1 days. Ankle ROM, 10-meter walking speed, and lower limb muscle activity via surface electromyography were measured during walking and stair ascent/descent. Results Ankle ROM was significantly lower in the patient group than in the control group for both active and passive movements, as well as walking speed. Lower limb muscle activity during walking was higher in the patient group than in the control group for all muscles examined. Lower limb muscle activity during stair ascent was higher in the patient group. On the other hand, during stair descent, no significant differences were found between the two groups regarding vastus medialis (p = 0.195) and soleus (p = 0.121) muscle activity; however, the other muscles showed significantly higher activity in the patient group. Conclusion In the present study, ankle ROM, walking speed, and lower limb muscle activity during walking and stair climbing were compared between the patients capable of independent walking after ankle fracture surgery and healthy controls. Ankle ROM and walking speed were significantly lower in the patient group; however, lower limb muscle activity during both walking and stair climbing was higher in the patient group compared to the control group, suggesting decreased muscle strength in the patients and highlighting the need for appropriate training. Although rehabilitation was conducted, some muscles exhibited higher activity levels than others, indicating the need for exercises tailored to each muscle.