Trunk muscle strength and low back pain

Area of Science:

• Biomechanics
• Musculoskeletal Health
• Rehabilitation Science

Background:

• Low back insufficiency affects trunk muscle strength.
• Accurate assessment of trunk muscle strength is vital for rehabilitation.

Purpose of the Study:

• To compare trunk muscle strength between young males with low back insufficiency and healthy controls.
• To evaluate the effectiveness of isokinetic testing in identifying specific muscle weaknesses.

Main Methods:

• Isokinetic dynamometry was used to measure maximal torque of trunk muscles (flexion, extension, lateral flexion).
• Measurements included isometric and slow isokinetic contractions in various trunk positions and pivot points.
• Two groups were studied: young males with low back insufficiency (n=7) and age-matched healthy controls (n=8).

Main Results:

• No significant differences in trunk extension or lateral flexion strength were found between groups.
• Significantly lower strength values were observed in the low back insufficiency group during the initial phase of isokinetic trunk flexion with the hip as the pivot point.
• No significant differences were noted for trunk flexion with the center of rotation at the L2-L3 level.

Conclusions:

• A comprehensive approach to trunk muscle strength assessment, considering different movement velocities, body positions, and pivot points, is essential.
• Specific dynamic trunk flexion weakness may be a key indicator in individuals with low back insufficiency.
• Further research is needed to understand the clinical implications of this specific weakness.