Standing on a declining surface reduces transient prolonged standing induced low back pain development

Area of Science:

• Biomechanics
• Occupational Health
• Ergonomics

Background:

• Prolonged standing is a common occupational risk factor for low back pain.
• Alternating between level and sloped standing positions has shown benefits in pain reduction.
• Isolating the effect of a declining surface is crucial to understand specific postural influences.

Purpose of the Study:

• To evaluate the effect of standing solely on a declining surface on low back pain.
• To isolate the influence of postural changes on pain development during prolonged standing.
• To investigate the role of hip kinematics in reducing standing-induced low back pain.

Main Methods:

• Seventeen participants underwent two 75-minute prolonged standing simulations: level ground and declining surface.
• Pain developers were identified based on pain scores during the level ground condition.
• Kinematic data including hip flexion and trunk-to-thigh angle were analyzed.

Main Results:

• 53% of participants developed low back pain on level ground.
• For pain developers, maximum pain scores were 58% lower when standing on the declining surface.
• Standing on the sloped surface increased hip flexion, trunk-to-thigh flexion, and posterior trunk center of gravity translation.

Conclusions:

• Standing solely on a declining surface effectively reduces low back pain in susceptible individuals.
• Observed postural changes, particularly increased hip flexion, may enhance pelvic stability.
• Hip kinematics are critical for mitigating low back pain associated with prolonged standing, beyond just lumbar spine posture.