Lateral trunk lean gait modification increases the energy cost of treadmill walking in those with knee osteoarthritis.

OBJECTIVE: To compare the energy expenditure of increased lateral trunk lean walking - a suggested method of reducing medial compartment knee joint load - compared to normal walking in a population of older adults with medial knee osteoarthritis (OA).

METHOD: Participants completed two randomly-presented treadmill walking conditions: 15 min of normal walking or walking with ten degrees of peak lateral trunk lean. Lateral trunk lean angle was displayed in front of the participant in real-time during treadmill conditions. Energy expenditure (VO2 and METs), heart rate (HR), peak lateral trunk lean angle, knee pain and perceived exertion were measured and differences between conditions were compared using paired t-tests.

RESULTS: Twelve participants (five males, mean (standard deviation (SD)) age 64.1 (9.4) years, body mass index (BMI) 28.3 (4.9) kg/m²) participated. All measures were significantly elevated in the lateral trunk lean condition (P < 0.008), except for knee pain (P = 0.22). Oxygen consumption (VO2) was, on average 9.5% (95% CI 4.2-14.7%) higher, and HR was on average 5.3 beats per minute (95% CI 1.7-9.0 bpm) higher during increased lateral trunk lean walking.

CONCLUSION: Increased lateral trunk lean walking on a treadmill resulted in significantly higher levels of steady-state energy expenditure, HR, and perceived exertion, but no difference in knee pain. While increased lateral trunk lean has been shown to reduce biomechanical measures of joint loading relevant to OA progression, it should be prescribed with caution given the potential increase in energy expenditure experienced when it is employed.