Impaired Lumbar Extensor Force Control Is Associated with Increased Lifting Knee Velocity in People with Chronic...

Area of Science:

• Biomechanics
• Neuromuscular Control
• Musculoskeletal Disorders

Background:

• Accurate force control by lumbar extensor muscles is crucial for daily activities like lifting.
• Impaired lumbar extensor force control is common in individuals with low-back pain (LBP).
• This impairment may contribute to altered lifting movement patterns observed in LBP patients.

Purpose of the Study:

• To investigate the relationship between lumbar extensor force control and lifting kinematics in chronic low-back pain patients.
• To determine if impaired force control is associated with specific lifting movement patterns.

Main Methods:

• Thirty-three participants with chronic LBP performed a weight-lifting task and an isometric lumbar extension force control task.
• Lumbar extensor force control was assessed using Root-Mean-Square Error (RMSE) during force production tasks.
• Lifting kinematics, including trunk and lower limb motion, were analyzed using phase plane analysis.

Main Results:

• Impaired lumbar extensor force control (higher RMSE) was associated with increased knee angular velocity in both sagittal and coronal planes during lifting.
• Specifically, RMSE during force increase (RMSE_A) correlated with sagittal and coronal knee angular velocity.
• These findings indicate a link between the ability to control lumbar extensor force and lower limb movement dynamics.

Conclusions:

• Impaired lumbar extensor force control in chronic low-back pain patients is associated with greater multiplanar knee movement velocity during lifting.
• The study suggests a potential interplay between lumbar and lower limb neuromuscular function in the context of LBP.
• These findings may inform rehabilitation strategies for individuals with chronic low-back pain.