The influence of whole body heating and cooling on the aftercontraction effect in the upper limb muscles

The effect of moderate body cooling and heating on the aftercontraction effect (ACE) was studied in muscles differing in their biomechanical functions. In the biceps muscle of the arm (a flexor muscle), the ACE increased with body cooling and tended to decrease with body heating. Heating of the deltoid muscle (an antigravity abductor) resulted in a higher ACE amplitude and shorter ACE duration, which suggests a complex interaction of the postural mechanisms that regulate the heat emission area and heat production. Cooling had no unambiguous effect on the deltoid muscle ACE. In general, ACE programming in response to thermal factors proved to depend on the biomechanical function of the muscle.