Anthropometric Predictors of Conventional Deadlift Kinematics and Kinetics: A Preliminary Study

Abstract

The purpose of this preliminary analysis was to determine if there are relationships between anthropometric characteristics (arm length, torso length, thigh length, and shank length) and conventional deadlift (CDL) kinematics and kinetics during a 5 sets of 5 repetitions (5 × 5) CDL routine in resistance-trained males. Eleven males who had experience with the deadlift exercise were included in this analysis (age: 21.5 ± 1.4 y; height: 180.7 ± 5.7 cm; body mass: 89.9 ± 16.0 kg). Anthropometrics were measured by a 3-dimensional optical scanner. The participants underwent a 5 × 5 CDL workout using a self-selected load corresponding to a rating of perceived exertion (RPE) of 8 out of 10. Performance outcomes were measured synchronously using a 3-dimensional 12-camera motion capture system and two force platforms. Outcomes were averaged across all sets and analyzed using multiple linear regression. The selected anthropometric variables were not significantly related to the CDL performance outcomes, except for concentric ankle work. However, in the overall model, anthropometric predictors did not significantly predict ankle concentric work (p = 0.11; R ² = 0.67; R_2adj = 0.45). Independently, thigh length significantly correlated with ankle concentric work (p = 0.03). In this model, thigh length accounted for 55% of the normalized variance in ankle concentric work. The results from this preliminary study suggest that arm length, torso length, and shank length may not play a clear role in the examined CDL outcomes, but thigh length may be positively correlated with ankle concentric work during a 5 × 5 CDL routine in resistance-trained males.

Keywords: Biomechanics; barbell velocity; ground reaction force; lower body work; rate of force development.

Figure 1

Representative avatar from 3-dimensional optical scanning. Anthropometric variables used as predictor variables in regression models were obtained from these scans.

Figure 2

Marker locations used in the present study.

Figure 3

Exemplar representation for the net sum of joint power across five repetitions of deadlift exercise. The data represent five repetitions, beginning in the starting position, after which the first repetition begins with a concentric phase (~3s) and ends with an eccentric phase (~7s). Repetitions two through five then occur with the same pattern. Concentric: Concentric phase of deadlift repetitions, defined as the time during each repetition where the net sum of joint power is positive; Eccentric: Eccentric phase of deadlift repetitions, defined as the time during each repetition where the net sum of joint power is negative.

Figure 4

Model coefficients for eccentric conventional deadlift performance outcomes.

Figure 5

Model coefficients for concentric conventional deadlift performance outcomes. * Indicates p ≤ 0.05

Figure 6

Model coefficients for select CDL outcomes after addition of quadratic term to model. * Indicates p ≤ 0.05