Individuals with varus thrust do not increase knee adduction when running with body borne load

Area of Science:

• Biomechanics
• Occupational Health
• Sports Medicine

Background:

• Osteoarthritis (OA) is a prevalent occupational hazard for military personnel.
• Understanding the impact of body-borne load on knee biomechanics is crucial for preventing OA in service members.

Purpose of the Study:

• To quantify the effects of varying body-borne load on knee biomechanics during running.
• To compare knee biomechanics between service members with and without varus thrust under different load conditions.

Main Methods:

• Eighteen military personnel (9 with varus thrust, 9 controls) ran with light, medium, and heavy loads.
• Knee biomechanics, including varus thrust and knee adduction, were recorded.
• Repeated measures ANOVA analyzed the effects of load and group on biomechanical parameters.

Main Results:

• Initially, the varus thrust group showed greater varus thrust and knee adduction posture than controls.
• With heavy loads, the varus thrust group reduced their varus thrust, while controls increased it.
• Controls also exhibited increased peak stance knee adduction moment with heavy loads, unlike the varus thrust group.

Conclusions:

• Body-borne load can alter knee biomechanics, potentially mitigating OA-related risk factors in individuals with varus thrust.
• Conversely, increased load may induce knee biomechanics associated with OA development in those without varus thrust.
• These findings highlight the complex interplay between load carriage, pre-existing biomechanical factors, and OA risk in military populations.