MUSCLE STRENGTH IN UNSTABLE CONDITIONS

The use of various exercises in unstable conditions aiming to improve balance and coordination has attracted much attention in the recent years. However, the impact of such exercises on strength has been poorly studied, partly because of the problematic reliability of the current methods of muscle strength assessment during such movements, limiting thus their practical use. Movement production in unstable conditions results in the reduction of maximum muscle strength since the total muscle force is diminished, co-contractions are increased, and muscle coordination is altered. The use of unstable platforms in resistance training should result in the development of higher levels of muscle activation via increased reliance on their stabilizing functions. Since this higher level of muscle activation is achieved with less resistance, such trainings could have a positive impact on muscle and joint rehabilitation after injuries, as well as in sport-specific trainings. However, the researches performed in the field of rehabilitation cannot be directly translated into the field od sports training due to different demands for muscle strength exercise in everyday activity (low loads, slow movements) and in sports activities (large loads, highly dynamic movements). Acta Medica Medianae 2011;50(2):53-56.