Towards evidence based strength training: a comparison of muscle forces during deadlifts, goodmornings and split squats

Abstract

BackgroundTo ensure an efficient and targeted adaptation with low injury risk during strength exercises, knowledge of the participant specific internal loading conditions is essential. The goal of this study was to calculate the lower limb muscles forces during the strength exercises deadlifts, goodmornings and splits squats by means of musculoskeletal simulation.Methods11 participants were assessed performing 10 different variations of split squats by varying the step length as well as the maximal frontal tibia angle, and 13 participants were measured performing deadlift and goodmorning exercises. Using individualised musculoskeletal models, forces of the Quadriceps (four parts), Hamstrings (four parts) and m. gluteus maximus (three parts) were computed.ResultsDeadlifts resulted highest loading for the Quadriceps, especially for the vasti (18–34 N/kg), but not for the rectus femoris (8–10 N/kg), which exhibited its greatest loading during split squats (13–27 N/kg) in the rear limb. Hamstrings were loaded isometrically during goodmornings but dynamically during deadlifts. For the m. gluteus maximus, the highest loading was observed during split squats in the front limb (up to 25 N/kg), while deadlifts produced increasingly, large loading over large ranges of motion in hip and knee.ConclusionsActing muscle forces vary between exercises, execution form and joint angle. For all examined muscles, deadlifts produced considerable loading over large ranges of motion, while split squats seem to be highly dependent upon exercise variation. This study provides key information to design strength-training programs with respect to loading conditions and ranges of motion of lower extremity muscles.

High‐density electromyography activity in various hamstring exercises

“…High activity levels in these exercises may facilitate training‐induced adaptations in the hamstrings, although adaptations in response to these exercises are unclear. In accordance with previous literature, particularly low overall hamstrings activity was observed in GM, which is apparently associated with low hamstring muscle forces in this exercise . Exercises inducing limited hamstrings activity are likely suboptimal to facilitate meaningful muscle adaptations.…”

“…In accordance with previous literature, 28 particularly low overall hamstrings activity was observed in GM, which is apparently associated with low hamstring muscle forces in this exercise. 29 Exercises inducing limited hamstrings activity are likely suboptimal to facilitate meaningful muscle adaptations. The relevance of the relative roles of individual hamstring muscles in hamstring injury is yet to be clarified.…”

“…In any case, in both lunge and CP, the overall hamstrings activity level is rather low, likely limiting meaningful adaptations in response to these exercises. Manipulating the shin angle during a lunge may expose the hamstrings to substantially higher forces, likely increasing hamstrings activity. However, it is unclear whether this manipulation alters the proximal‐distal activity pattern.…”

The Capacity of Generic Musculoskeletal Simulations to Predict Knee Joint Loading Using the CAMS-Knee Datasets

“…However, the capacity of musculoskeletal models to predict KCFs during other activities has been less thoroughly studied. 37,43 Furthermore, because musculoskeletal models have previously struggled to predict absolute measures of joint loading, they are often used instead to predict differences in metrics between e.g., subjects, groups of subjects, activities, or pathologies. However, due to the limited number of subjects and activities in the publicly available benchmark validation datasets, the ability to establish differences has not been extensively validated.…”

Training Load Demands Measured by Surface Electromyography Wearable Technology When Performing Law Enforcement-Specific Body Drags

“…The body drag, especially how it was performed in this study (Peace Officer Standards and Training, 2012;Lockie et al, 2018b;Lockie et al, 2019b;Lockie et al, 2019e;Moreno et al, 2019), has some similarities to a deadlift. In an analysis of lower-body strength exercises, Schellenberg, Taylor, & Lorenzetti (2017) found that the quadriceps were most active in the deadlift. The need to physically stand with the dummy by extending the legs could have increased the QUAD TL.…”