Amplitude and Frequency Analysis of Pelvic Limb Muscle Activity during a Trot in Normal, Healthy Dogs Using Surface Electromyography

Introduction: Our objective was to describe the surface electromyography (sEMG) percent maximum/minimum amplitude (%MM) and frequency signals as median frequencies (MDF) of the vastus lateralis (VL), biceps femoris (BF), semitendinosus (ST), and gastrocnemius (GN) bilaterally in healthy dogs at a trot. We hypothesized that %MM and MDF could be recorded and assessed during the gait cycle in healthy dogs.

Materials and Methods: Surface electrodes were applied bilaterally on 10 client-owned dogs. Dogs were trotted over three in series force plates while obtaining telemetric sEMG signals. % MM and MDF were calculated from raw sEMG signals. %MM and MDF were plotted to four gait cycle subphases (S1, S2, S3, and S4).

Results: Peak %MM activation patterns were achieved during the early stance (S1) and late swing (S4) for all muscles. Biphasic peak patterns were present during early swing (S3) for the ST and GN. A mean of the median frequencies of each muscle was observed between 20 to 60 Hz during a gait cycle at a trot. Peak MDF were achieved during S1 and S4 for the VL, BF, and GN and S3 for the ST.

Discussion/Conclusion: The results support our hypothesis that %MM and MDF can be recorded in the VL, BF, ST, and GN of healthy dogs at a trot. The %MM and MDF have the potential to enhance the characterization of gait in dogs with applications to further objectively assess musculoskeletal treatment strategies.

Acknowledgment: None of the authors declare a conflict of interest with this study.