Alternative methods of normalising EMG during running

Abstract

We evaluated possible methods of normalising EMG measured during running. MVC, Sprint and 70% Peak Running Speed methods were evaluated and their repeatability, reliability and sensitivity to incremental running speed were compared. Twelve runners performed the same experimental protocol on three separate occasions. Each day, subjects firstly performed MVCs, followed by a 20 m maximal sprint (with a 20-30 m run-up). Following this, they performed the peak running speed (PRS) test until exhaustion. After which they ran at 70% of PRS for 5 laps. Results indicated that normalising EMG data to MVC and Sprint methods are more repeatable for VM, BF, MG and RF, VL, LG, respectively, with the average ICC>0.80. The 70% PRS demonstrated poor to fair levels of repeatability ranging between ICC 0.27 and 0.70. Whereas the 70% PRS method had the least intra-subject variability and the greatest sensitivity to increasing running speeds. More specifically, demonstrating significant changes in muscle activity in VM with increasing running speed while MVC and Sprint methods were unable to detect these changes. The dynamic methods were the most appropriate for EMG normalisation showing repeatability, better intra-subject reliability and better sensitivity during running over different days and for once-off measurements.

Normalisation method can affect gluteus medius electromyography results during weight bearing exercises in people with hip osteoarthritis (OA): A case control study

“…Numerous studies have attempted to compare EMG normalisation methods, the majority of which have been conducted on healthy controls [6,10] Results showed that although both normalisation methods resulted in predominantly higher normalised EMG amplitude in the hip OA group, a greater number of significant between-group differences were identified using MVIC normalisation, particularly in the Step exercises. Amplitudes were more comparable between groups using PDM normalisation, resulting in significant betweengroup differences only in the Squat exercise.…”

“…Numerous studies have attempted to compare EMG normalisation methods, the majority of which have been conducted on healthy controls [6,10] so extrapolation to populations with pathology is limited. Although, there appears to be no consensus regarding the best methods, a comprehensive review by Burden [6] recommended that task normalization methods such as PDM and MDM methods were preferable to MVIC methods to reduce inter-individual variation in healthy controls, but of limited value when comparing across studies or when reapplication of electrodes is required.…”

Normalization of EMG Signals: To Normalize or Not to Normalize and What to Normalize to?

“…• knee extension, knee flexed 90°, hip flexed 90° (sitting) [38,43] • knee extension, knee flexed 60°, hip flexed 90° (sitting) [44,45] • knee extension, knee flexed 45° (sitting) [37] vastus medialis • knee extension, knee flexed 60° (sitting) [44,45] • knee extension, knee flexed 90°, hip flexed 90° (sitting) [43] rectus femoris • knee extension, knee flexed 90°, hip flexed 80° to 90° (sitting) [35,36,38,43] • knee extension, knee flexed 60°, hip flexed 90° (sitting) [44][45][46] lateral hamstring (biceps femoris) long head…”

“…• knee flexion, knee flexed 90°, hip flexed 90° (sitting) [38] • knee flexion, knee flexed 60° (sitting) [44,46] • knee flexion, knee flexed 60° (prone) [45] • knee flexion, knee flexed 90°, hands clasped behind head (prone) [37] gastrocnemius lateralis…”

“…• ankle plantar flexion, ankle -15°, knee flexed 30° [44] • ankle plantar flexion, mid ankle position (standing unilateral -body weight) [47] • ankle plantar flexion, ankle, knee and hip in neutral position (prone) [45] gastrocnemius medialis…”