Modified step aerobics training and neuromuscular function in osteoporotic patients: a randomized controlled pilot study

BACKGROUND: Training programs directed to improve neuromuscular and musculoskeletal function of the legs are scarce with respect to older osteoporotic patients. We hypothesized that a modified step aerobics training program might be suitable for this purpose and performed a randomized controlled pilot study to assess the feasibility of conducting a large study. Here we report on the training-related effects on neuromuscular function of the plantar flexors. PATIENTS AND METHODS: Twenty-seven patients with an age of at least 65 years were enrolled and randomized into control and intervention group. The latter received supervised modified step aerobics training (twice weekly, 1 h per session) over a period of 6 months. At baseline, and after 3 and 6 months neuromuscular function of the plantar flexors, i.e., isometric maximum voluntary torque, rate of torque development and twitch torque parameters were determined in detail in all patients of both groups. RESULTS: Twenty-seven patients (median age 75 years; range 66–84 years) were randomized (control group n = 14; intervention group n = 13). After 3 and 6 months of training, maximum voluntary contraction strength in the intervention group was significantly higher by 7.7 Nm (9.1%; 95% CI 3.3–12.2 Nm, P < 0.01) and 12.4 Nm (14.8%; 95% CI 6.4–18.5 Nm, P < 0.01) compared to controls. These changes were most probably due to neural and muscular adaptations. CONCLUSION: It is worthwhile to investigate efficacy of this training program in a large randomized trial. However, a detailed neuromuscular assessment appears feasible only in a subset of participants.