Beneficial effects of a gait used while wearing a kimono to decrease the knee adduction moment in healthy adults

Area of Science:

• Biomechanics
• Orthopedics
• Kinesiology

Background:

• The knee adduction moment (KAM) is a key factor in medial knee osteoarthritis (OA) development.
• Current gait modifications to reduce KAM often require voluntary leg alignment changes.
• Investigating natural walking styles for KAM reduction is crucial for OA prevention.

Purpose of the Study:

• To investigate the biomechanical effects of the Nanba walk on reducing the knee adduction moment (KAM).
• To assess changes in trunk and hip muscle activation during Nanba walking.
• To evaluate the potential of Nanba gait as a strategy for knee OA prevention and treatment.

Main Methods:

• Utilized a 3D motion analysis system with 10 cameras and a force plate.
• Measured KAM and lever arm lengths in 29 healthy adults during normal and Nanba walking.
• Assessed surface electromyography (EMG) of hip and trunk muscles (IO, EO, MF, Gmed), analyzing integrated EMG (iEMG).

Main Results:

• Nanba walking significantly decreased both 1st and 2nd peak KAMs compared to normal walking (P = 0.002, P<0.001).
• Lever arm lengths were significantly reduced during Nanba walking (p = 0.023, p<0.001).
• Increased iEMGs were observed in IO, EO, and Gmed muscles during Nanba walking, indicating higher muscle activation.

Conclusions:

• The Nanba walk effectively reduces the knee adduction moment (KAM) by decreasing lever arm length.
• This gait modification enhances trunk and hip muscle activation, particularly the obliquus and gluteus medius muscles.
• Nanba gait presents a promising, natural strategy for the prevention and/or treatment of medial knee osteoarthritis.