Does decrease of the thoracic kyphosis influence decrease knee adduction moment during gait? A preliminary study of a...

Area of Science:

• Biomechanics
• Orthopedics
• Human Movement Science

Background:

• The knee adduction moment is a critical factor in knee joint loading and osteoarthritis development.
• Thoracic kyphosis, an outward curvature of the thoracic spine, may influence lower limb biomechanics.
• Understanding the relationship between spinal posture and knee joint forces is essential for injury prevention and rehabilitation.

Purpose of the Study:

• To investigate the effect of reducing thoracic kyphosis on the knee adduction moment during gait.
• To determine if a specific maneuver to decrease kyphosis impacts gait-related knee joint loading in healthy young adults.

Main Methods:

• Twenty-nine healthy young adults (15 males, 14 females) participated.
• Thoracic kyphosis was measured using a SpinalMouse during normal standing and with a draw-in maneuver.
• A 3D motion analysis system and force plate captured gait data to calculate the knee adduction moment.

Main Results:

• The draw-in maneuver significantly decreased thoracic kyphosis angles (41.0° ± 7.4°) compared to normal standing (43.0° ± 7.9°).
• While overall knee adduction moment did not significantly change, 20 participants showed a significant decrease in the 1st peak knee adduction moment (55.7 ± 24.3 × 10⁻³) with the maneuver.
• This decrease in peak knee adduction moment was observed when thoracic kyphosis was successfully reduced.

Conclusions:

• Reducing thoracic kyphosis angle through a draw-in maneuver can lead to a decrease in the knee adduction moment during gait.
• These findings highlight a potential biomechanical strategy to modulate knee joint loading by altering spinal posture.