Differences in Psoas Major Muscle Properties Between Elite Athletes with and Without Chronic Low Back Pain

Area of Science:

• Sports Medicine
• Musculoskeletal Biomechanics
• Rehabilitation Science

Background:

• The connection between psoas major (PM) muscle dysfunction and low back pain (LBP) is proposed but not fully understood.
• Elite athletes in sports like gymnastics and wushu are susceptible to chronic LBP.
• Investigating specific PM muscle properties is crucial for understanding LBP in this population.

Purpose of the Study:

• To examine the association between psoas major muscle stiffness, strength, and flexibility and chronic LBP in elite athletes.
• To determine if PM muscle properties are linked to the severity of LBP and related functional impairments.

Main Methods:

• Ninety-nine elite athletes (gymnasts, wushu athletes) with and without chronic LBP participated.
• Psoas major muscle stiffness was measured using ultrasound shear wave elastography.
• Muscle strength, flexibility, LBP severity, and functional disability were assessed; statistical analyses included ANCOVA and correlation.

Main Results:

• Increased PM muscle stiffness on the affected side was significantly associated with LBP, particularly on the dominant side.
• Higher PM stiffness correlated with increased LBP-related dysfunction.
• No significant associations were found between PM muscle strength or flexibility and LBP.

Conclusions:

• Psoas major muscle stiffness, rather than strength or flexibility, is associated with chronic LBP in elite athletes.
• These findings suggest PM stiffness may be a contributing factor to LBP in high-risk sports.
• Further research is needed to establish the causal and temporal relationship between PM stiffness and LBP.