Effect of three-week exercise program on muscle strength and joint mobility in patients with diabetic polyneuropathy: Randomized controlled trial.

Background: Limited joint mobility is the proven risk factor for diabetic foot ulceration when present in the subtalar and first metatarsophalangeal joints. Evidence shows that a foot-related exercise program, combined with a health-promoting program, can improve the signs and symptoms of diabetic polyneuropathy, enhance gait, restore mobility in the foot and ankle joints, redistribute pressure while walking, and increase foot strength and function. As a result, these exercise programs can help mitigate the risk factors for diabetic foot ulceration.

Aim: To determine the effect of supervised stretching, strengthening, functional and walking exercises on joint mobility and muscle strength in patients with diabetic polyneuropathy.

Methods: This was a randomized controlled trial conducted in a tertiary hospital. The study included 82 participants allocated into the intervention group (alpha-lipoic acid and exercise on 15 consecutive therapeutic days, n = 42) and control group (alpha lipoic acid only, n = 40). Muscle strength included dorsal and plantar flexors dynamometry and strength score, while range of motion included ankle, subtalar and first metatarsophalangeal joint goniometry.

Results: Change of motion range was significantly higher in the intervention group compared to the control group regarding ankle joint on day 15 (9.9 ± 7.2 vs 0.1 ± 3.3; P = 0.006) and month 6 (2.8 ± 7.3 vs -0.9 ± 4.1; P < 0.001), subtalar joint on day 15 (7.5 ± 5.1 vs -0.25 ± 2.25; P < 0.001) and month 6 (3.9 ± 6.4 vs -0.13 ± 3.49; P < 0.001). Change in dorsal flexors was significantly higher in the intervention group compared to the control group on day 15 (2.62 ± 1.69 vs 0.10 ± 1.35; P < 0.001) and month 6 (0.66 ± 2.38 vs -0.75 ± 1.94; P = 0.004) as well as plantar flexors on day 15 (3.3 ± 1.6 vs 0.3 ± 1.5; P < 0.001) and month 6 (1.8 ± 2.2 vs -0.9 ± 2.1; P < 0.001). Muscle strength score change was significantly lower in the intervention group compared to the control group on day 15 (-1.45 ± 1.42 vs -0.03 ± 0.16; P < 0.001) and month 6 (-1.17 ± 1.53 vs 0.20 ± 0.56; P < 0.001).

Conclusion: Exercise in combination with alpha-lipoic acid can improve joint mobility, as well as strength of the foot and lower leg muscles in patients with diabetic polyneuropathy.