Neuromuscular function and balance of prepubertal and pubertal blind and sighted boys


Arja Häkkinen, Department of Physical Medicine and Rehabilitation, Jyväskylä Central Hospital, 40620 Jyväskylä, Finland. Tel: +358 14 269 1919. Fax: +358 14 269 2931. E-mail:


Aim: To compare the neuromuscular function and balance of blind prepuberty- and puberty-aged boys to those with normal sight. Methods: Thirty-three prepubertal (aged 9–13 y) and pubertal (aged 15–18 y) blind and sighted boys were tested for muscle mass thickness, electromyography and maximal isometric strength, dynamic explosive actions, and balance. Results: There was no difference in the muscle mass thickness, maximal strength or vertical jump between the blind and sighted boys. However, fitness-ball throwing and five-jump distances were significantly shorter in both blind groups compared to the sighted groups. One-leg stance of the prepuberty-aged sighted boys was 109 (67) s and in blind boys 32 (12) s, and in the puberty-aged boys 120 (57) s and 31 (8) s, respectively. When vision was blocked in the sighted boys, differences between the blind and sighted boys disappeared.

Conclusion: The results showed comparable performance between prepubertal and pubertal blind and sighted boys in the static physical fitness tests. However, balance and performance in dynamic multi-joint tests did not improve similarly in the blind groups compared to sighted groups, indicating that maturation, learning and experience by themselves cannot compensate for the loss of sight.