Purpose: This study compared the kinematics and kinetics of the knee joint during traditional step-over-step (SOS) and compensatory step-by-step lead-leg (SBSL) and trail-leg (SBST) stair ambulation patterns.
Methods: Seventeen (M:9) healthy adults completed five trials of ascent and descent using three different stepping patterns: 1) SBSL, 2) SBST, and 3) SOS. Kinematics and kinetics were collected with an optoelectronic motion-tracking system and a force plate embedded into a four-step staircase. An inverse-dynamics link-segment model (QGAIT system) was used to calculate the net joint kinetics.
Results: During stair ascent, different peak anteroposterior (AP) forces were observed across all three stepping patterns (SOS > SBSL > SBST, P < 0.05). During ascent, the flexion moments of SOS (0.96 N·m·kg−1) and SBSL (0.97 N·m·kg−1) patterns were similar and much larger than the SBST moments (0.14 N·m·kg−1). In the descent conditions, the initial AP peak force for SOS was larger than that of SBSL and SBST. However, the second peak force for SOS (4.92 N·kg−1) and SBST (4.68 N·kg−1) were larger than SBSL (1.57 N·kg−1). During descent, the initial peak flexion moment for the SOS pattern was larger than SBSL and SBST, whereas during the second peak, SOS (1.05 N·m·kg−1) and SBST (1.11 N·m·kg−1) were no different and larger than SBSL (0.18 N·m·kg−1).
Conclusion: Overall, SBSL during ascent and SBST during descent had the highest loads. These results increase our understanding of alternative stepping patterns and have important clinical (reduction of loading on injured/diseased leg) and rehabilitation implications.
1School of Kinesiology and Health Studies and 2School of Rehabilitation Therapy, Queen's University, Kingston, CANADA
Address for correspondence: Patrick A. Costigan, Ph.D., Physical Education Centre, Biomechanics Laboratory, Queen's University, K7L 3N6; E-mail: Pat.Costigan@queensu.ca.
Submitted for publication March 2007.
Accepted for publication June 2007.