Ischemic Preconditioning Alters Gait Patterns In Individuals With Knee Osteoarthritis

PURPOSE: To investigate the effects of ischemic preconditioning (IC) on gait performance in patients with knee osteoarthritis (KOA). METHODS: Seven participants (3F/4M, 66.0 ± 11.1 years, 89.4 ± 22.5 kg, 171.2 ± 8.8 cm) with unilateral symptomatic KOA walked on a split-belt treadmill at a self-selected speed for six-minutes with clusters of reflective markers attached to the thorax, sacrum, bilateral thighs, bilateral calves, and bilateral forefeet. Following walking, all participants completed IC on the involved limb every other day for seven sessions. Each session of IC lasted 50 minutes, with 5 minutes of inflation to 225 mmHg followed by 5 minutes of reperfusion for 5 cycles. After the final IC session, participants walked as a self-selected pace again. Kinematic data were reduced to 100 points to represent 0-100% of the gait cycle, with 60% representing toe off during walking. Heel strike was defined as the point when vertical ground reaction forces exceeded 20 N. Mean differences (degrees) and associated pooled standard deviations were calculated for periods of the gait cycle when 90% confidence intervals did not overlap for three or more consecutive points. RESULTS: Participants walked an average of 0.57 ± 0.24 m/s before IC and walked an average of 0.63 ± 0.28 m/s after IC (p = 0.28). Following IC, participants with KOA demonstrated decreased knee flexion at terminal stance (8.42°) and terminal swing (6.07°) and increased knee external rotation during midstance (8.57°) compared to pre-IC. Participants also demonstrated reduced hip adduction during early stance (3.59°) and midstance (2.53°) as well as increased hip internal rotation during early stance (4.63°) compared to pre-IC. Lastly, participants demonstrated reduced trunk rotation towards the ipsilateral side during terminal stance (4.52°) during gait compared to pre-IC. CONCLUSIONS: Seven sessions of IC led to changes in gait kinematics in participants with KOA. These changes were largely in the frontal and transverse plane, which may suggest an altered “screw-home” mechanism that more closely mimics healthy gait patterns. IC is a noninvasive intervention that should continue to be investigated in clinical patients with KOA to modify gait patterns and improve mobility. UIC Applied Health Sciences Interdisciplinary Pilot Award