Managing lower extremity loading in distance running by altering sagittal plane trunk leaning

Area of Science:

• Biomechanics
• Sports Medicine
• Running Injury Prevention

Background:

• Trunk lean angle is an underutilized biomechanical factor for managing lower extremity joint loads during running.
• Altering trunk posture may help reduce the risk of running-related overuse injuries.

Purpose of the Study:

• To systematically investigate the effects of varying trunk lean angles on lower extremity joint loading in distance runners.
• To establish dose-response relationships between trunk lean and joint loading for clinical application in overuse injury management.

Main Methods:

• Thirty recreational runners (15 male, 15 female) performed running trials at 2.5 m/s on a force-instrumented treadmill.
• Five distinct trunk lean conditions were tested, with kinematic and kinetic data captured for analysis.

Main Results:

• Increasing trunk lean angle (from -2° to 28°) significantly increased hip joint loading (sagittal and transverse planes) but decreased knee joint loading (sagittal plane).
• Each degree of anterior trunk lean increased cumulative hip joint loading by 3.26 Nm·s/kg/1000 m and decreased knee joint loading by 1.08 Nm·s/kg/1000 m.
• Hip joint abduction loading was also reduced with trunk leaning.

Conclusions:

• Modulating trunk lean angle is an effective method for redistributing lower extremity joint loads between the knee and hip joints.
• Anterior trunk leaning reduces knee and hip abduction loading but increases hip loading in the sagittal and transverse planes.
• Clinical implementation requires consideration of increased hip musculature demand, dynamic stability, and potential impact on running economy.