Voluntary control of muscle tension in lengthened and intact limbs in different ranges of force load

Data confirming the hypothesis that there is a range of isometric loads where subjects organize voluntary control of muscle tension with the maximum precision and minimum specific energy expenditure are presented, the energy expenditure being estimated indirectly by the ratio of the area (integral) of the summary electromyogram (EMG) to the force momentum impulse. The asymmetries of the integrated estimates of visuomotor tracking with the use of isometric control organs have been analyzed in 23 patients (6 men and 17 women) aged 15–35 years in different periods, after surgical elimination of the difference between the lengths of their lower extremities. A slightly distinct zone of minimization of the integrated estimates of discrete visuomotor tracking in the range of 25–35% of the maximum force of the muscle group tested (foot dorsal flexors) has been found in healthy subjects (26 healthy men aged 19–39 years) and orthopedic patients (the intact extremity). The zone of optimal loads is more distinct in patents on the side of lengthening; this zone tends to shift towards the region of weaker forces.