Isokinetic strength training in below-knee amputees.

Area of Science:

• Exercise Physiology
• Rehabilitation Medicine
• Biomechanics

Background:

• Below-knee amputees often experience reduced muscle strength and functional mobility.
• Isokinetic training is a method to improve muscle strength and endurance.
• Understanding the effects of training on muscle adaptations is crucial for rehabilitation.

Purpose of the Study:

• To investigate the effects of isokinetic training on knee extensor and flexor muscles in below-knee amputees.
• To assess changes in muscle strength, fiber type distribution, and muscle size after training.
• To evaluate the impact of training on functional mobility and walking ability.

Main Methods:

• Eight below-knee amputees underwent 8-12 weeks of isokinetic training at various angular velocities.
• Isokinetic and isometric strength tests were performed before and after training.
• Muscle biopsies analyzed vastus lateralis fiber cross-sectional areas; computerized tomography measured thigh muscle CSA.

Main Results:

• Significant increases in peak torque for knee extension in the amputated leg and for knee extension and isometric strength in the non-amputated leg.
• Increased cross-sectional area of type II muscle fibers in the amputated leg, with no significant changes in overall thigh muscle size.
• Patients reported more than double their walking distance and improved mobility without aids post-training.

Conclusions:

• Isokinetic training effectively enhances knee muscle strength and specifically targets type II (fast-twitch) muscle fibers in below-knee amputees.
• Training-induced strength gains and muscle fiber adaptations correlate with significant improvements in functional mobility and walking capacity.
• The study highlights the potential of targeted isokinetic training protocols for optimizing rehabilitation outcomes in amputee populations.