AXIAL ACCELERATION OF THE SHANK AND EMG DIFFERENCES BETWEEN ISOCALORIC HIGH-INCLINE WALKING AND LEVEL GRADE JOGGING

Purpose: To examine muscle activation and biomechanical differences between high incline walking (HIW) at 20% grade and level grade jogging (LGJ) at isocaloric intensity on a treadmill. Methods: Physically inactive men and women between the ages of 18-59 years of age completed the study. Participants (n=22) completed two isocaloric exercise trials (HIW and LGJ) ten minutes in duration. EMG data was obtained from the Bicep Femoris (BF), Glute (GT), Lateral Gastrocnemius (LG), Tibialis Anterior (TA), Vastus Lateralis (VL), Anterior Deltoid (AD), Erector Spinae (ES) and Soleus (SOL). Axial acceleration was determined by IMU data from the shank. Results: When subjects were matched at isocaloric intensities between LGJ and HIW, mean peak axial acceleration was significantly higher in the run than in the walk (p<.001). Peak EMG activation was significantly greater during LGJ in BF (p=.02), GT (p=.01), LG (p=.006), TA (p=.001), VL (p=.003) when compared to HIW. ES and SOL peak EMG activation did not differ between trials. Conclusion: Isocaloric LGJ results in predominantly greater peak muscle activation and an increase in axial acceleration.