Effect of Velocity-Based Loading on Acceleration Kinetics and Kinematics During Sled Towing

Bentley, Ian; Sinclair, Jonathan K.; Atkins, Steve J.; Metcalfe, John; Edmundson, Christopher J.

Abstract

Sled towing
(ST) provides an external load in the form of a sled towed
using a shoulder or waist harness and cord behind the athlete.
Loading strategies have varied greatly between studies,
and despite many investigations, there is little agreement on
the optimum sled loading to develop the acceleration phase.
The aim of this study was to investigate the kinetics and
kinematics of velocity-based ST during the acceleration
phase of sprinting. Twelve academy rugby league players
performed a series of 6-m sprints in different conditions;
uninhibited, 10, 15, and 20% velocity decrement (VDec).
Sagittal plane kinematics and kinetic measures were examined
using 1-way repeated-measures analysis of variance.
Results indicated that ST affected trunk, knee, and ankle
AU5 joint kinematics (p < 0.05). Peak knee flexion increased as
sled loads increased (p < 0.05), which may enable athletes
to lower their center of mass and increase their horizontal
force application. Net horizontal and propulsive impulse
measures were greater in all sled conditions (p < 0.05),
which increased significantly because sled loadings were
heavier. In conclusion, this study highlights the effects of
differential loads to help coaches understand acute kinetics
and kinematic changes to improve the planning of sprint
training.

• Journal Article Type: Article
• Acceptance Date: Apr 9, 2018
• Online Publication Date: Oct 5, 2018
• Publication Date: Apr 1, 2021
• Deposit Date: Oct 23, 2018
• Publicly Available Date: Oct 5, 2019
• Journal: Journal of Strength and Conditioning Research
• Print ISSN: 1064-8011
• Electronic ISSN: 1533-4287
• Publisher: Lippincott, Williams & Wilkins
• Volume: 35
• Issue: 4
• Pages: 1030-1038
• DOI: https://doi.org/10.1519/jsc.0000000000002850
• Keywords: Physical Therapy, Sports Therapy and Rehabilitation, Orthopedics and Sports Medicine, General Medicine
• Publisher URL: https://doi.org/10.1519/JSC.0000000000002850
• Related Public URLs: https://journals.lww.com/nsca-jscr/pages/default.aspx