Abstract
Objective: To describe phase-specific normative reference data for tarsal joint kinematics and lower limb muscle activity during constant-speed treadmill walking in healthy Beagles.
Methods: Six healthy Beagles walked on a treadmill at 0.7 m/s. The tarsal joint angle and surface electromyography (sEMG) of the gastrocnemius medialis (GASM) and tibialis cranialis (TC) were synchronously recorded. Gait cycles were time-normalized to 0–100%, and phase-averaged normalized sEMG amplitudes (%EMG) were calculated for five gait phases: loading response (LR), middle stance (MidSt), pre-swing (PSw), early swing (ESw), and late swing (LSw). The phase differences in %EMG were analyzed using the Friedman test. In addition, the inter-individual waveform similarity and timing of peak muscle activity were quantified.
Results: The tarsal joint flexed transiently during LR, extended through MidSt, and reached peak extension and flexion during PSw and ESw, respectively. GASM activity was highest during LR and increased further during LSw, whereas TC activity increased from PSw and was highest during ESw. The phase-averaged %EMG differed significantly among the gait phases for both muscles (p<0.001). The mean inter-individual waveform similarity was r=0.88 for the tarsal angle, r=0.93 for GASM %EMG, and r=0.71 for TC %EMG. GASM peak timing occurred at 1.2±1.6%GC in LR and at 96.2±1.9%GC in LSw, whereas TC peak timing occurred at 69.8±6.9%GC in ESw.
Conclusion: Tarsal kinematics and GASM and TC activity in healthy Beagles exhibited phase-specific coordination during treadmill walking. These data provide normative reference information for phase-based interpretation of canine gait abnormalities and for monitoring rehabilitation outcomes.
