Dynamic electromyography in active and limited walking below-knee amputees

Area of Science:

• Biomechanics
• Kinesiology
• Prosthetics

Background:

• Peripheral vascular insufficiency is a common cause for lower-limb amputations.
• Below-knee amputees often face challenges in gait mechanics and muscle activation patterns.

Purpose of the Study:

• To investigate the electromyography (EMG) activity of quadriceps and hamstring muscles during walking in below-knee amputees.
• To compare muscle activation between community walkers and limited household ambulators with dysvascular amputations.

Main Methods:

• Walking electromyography was conducted on 12 below-knee amputees at least 1 year post-surgery.
• Participants were categorized into community walkers (n=7) and limited household ambulators (n=5).
• EMG data of quadriceps and hamstring muscles were analyzed throughout the gait cycle.

Main Results:

• Active walkers demonstrated significantly higher quadriceps (60%) and hamstring (64.7%) muscle activity compared to limited walkers (44.6% and 53.8%, respectively).
• Quadriceps activity initiation was earlier in active walkers.
• Limited walkers exhibited decreased muscle activity in both groups, failing to utilize these muscles for propulsion.

Conclusions:

• Dysvascular below-knee amputees with limited walking ability do not effectively use quadriceps and hamstring muscles for propulsion.
• These individuals may not benefit from knee joint preservation due to altered muscle activation strategies.
• Further research is needed to understand compensatory mechanisms and optimize prosthetic use in this population.