Mechanical and neuromuscular changes with lateral trunk lean gait modifications

Area of Science:

• Biomechanics
• Kinesiology
• Orthopedics

Background:

• Lateral trunk lean (LTL) is a proposed intervention for knee osteoarthritis.
• The impact of increased muscular demands during LTL gait has not been fully evaluated.

Purpose of the Study:

• To compare lower extremity and trunk muscle activation during normal versus increased LTL gait in healthy adults.
• To assess the effects of increased LTL gait on joint mechanics, specifically knee adduction moment (KAM).

Main Methods:

• Twenty healthy adults participated, performing normal and increased LTL gait conditions.
• Motion capture and force plates were used to measure LTL angle, KAM, and gait speed.
• Surface electromyography recorded activation of six trunk and hip muscles.

Main Results:

• Increased LTL gait significantly increased peak LTL angle and decreased gait speed.
• A significant decrease in the first peak KAM was observed during LTL gait.
• Activation of external oblique and iliocostalis muscles increased significantly, while other measured muscles showed no change.

Conclusions:

• Increased LTL gait effectively reduces medial knee compartment loading by decreasing early/mid-stance KAM.
• Observed increases in trunk muscle activation were small to moderate and unlikely to cause short-term injury.
• Further longitudinal studies are recommended to assess LTL's long-term effectiveness and safety for knee osteoarthritis.