Farthing, J. P., Krentz, J. R., & Magnus, C. R. (2009). Does strength training the free limb attenuate strength loss during unilateral immobilization? ACSM 56th Annual Meeting, Seattle, Washington. Presentation number 2464.

This study determined if strength training the free limb during a three-week period of unilateral immobilization reduced strength loss in the immobilized limb. Right-handed Ss were assigned to three groups. One group (N = 10) wore a cast and trained the free arm. A second group (N = 10) wore a cast and did not train. A third group (N = 10) received no treatment. Casts were applied to the non-dominant (left) wrist and hand by a physician. Strength training involved maximal isometric ulnar deviation (right hand) five days per week. Peak torque, electromyography, and muscle thickness were assessed in both arms before and after the intervention.

The free-arm training group improved right arm strength. The immobilized arm of free-arm training group did not change in strength or muscle thickness. The immobilized arm of free-arm non-training group decreased in strength and muscle thickness. The control group showed no changes in the right or left arm. Agonist muscle activation remained unchanged after the intervention for both arms with no group differences.

Implication. Strength training of the free limb prevented strength loss and probably muscle atrophy in the immobilized limb during unilateral immobilization.

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