WCR players maintain sprint performance but alter propulsion biomechanics after simulated match play

Introduction:

The ability to accelerate rapidly and attain a high maximal velocity are key indicators of WR performance. These activities rely on the small muscle mass of the upper limb, which impose a large mechanical demand on the shoulder and coincide with detrimental glenohumeral kinematics linked to reduced subacromial space.

WR players exhibit asymmetries in both kinetics during sprinting and shoulder kinematics during submaximal propulsion in a non-fatigued state. Thus, if simulated WR match play negatively amplifies these asymmetries even further, the uneven acute and chronic stress imposed by wheelchair sprinting throughout a game may be substantial.

Study aim:

1) To establish whether a sports-specific intermittent sprint protocol (ISP) decreases wheelchair sprint performance.

2) To examine alterations in the kinetic, joint kinematic, and the asymmetries therein, during wheelchair sprinting in elite WR players with or without SCI.

Methods:

Fifteen international WR players (age 30.3 ± 5.5 years) performed two 10-s sprints on a dual roller wheelchair ergometer before and immediately after a sports-specific intermittent sprint protocol (ISP).

The ISP consisted of four 16-min quarters which incorporated prescribed propulsion speeds at various percentages of participant's peak velocity (V_max) determined from the pre-ISP sprint trials. Players completed the test in their own individualized rugby wheelchair used in training and competitions.

Physiological measurements (heart rate, blood lactate concentration, and rating of perceived exertion) were collected. Three-dimensional thorax and bilateral glenohumeral kinematics were quantified.

Main findings:

• Players maintained peak velocity and distance during wheelchair sprinting post-ISP.
• Players displayed alterations in kinetics, joint kinematics, and asymmetries of wheelchair sprinting following the ISP.
• Players significantly increased blood lactate concentration, RPE, and HR following the ISP, indicating the development of physiological fatigue. Yet, sprint performance was not impaired.
• All players reported a high level of exertion (RPE >16) which was comparable to peak values reported during WR match play.
• Following SP and during the acceleration phase of sprinting, players propelled their wheelchairs with reduced peak thorax flexion and glenohumeral abduction but utilized larger contact angles, alongside greater contact angle asymmetries, and glenohumeral flexion asymmetries. 
• Following ISP and during the maximal velocity phase of sprinting, players exhibited lower peak thorax flexion and glenohumeral abduction but increased both the ROM and asymmetries of glenohumeral abduction/adduction. 
• Post-ISP, during the acceleration phase of sprinting players with SCI significantly increased asymmetries in both peak power and glenohumeral abduction. Whereas these parameters were not significantly altered in those with non-SCI. 

Reference:

Briley SJ, O'Brien TJ, Oh YT, Vegter RJK, Chan M, Mason BS, Goosey-Tolfrey VL. Wheelchair rugby players maintain sprint performance but alter propulsion biomechanics after simulated match play. Scand J Med Sci Sports. 2023 Sep;33(9):1726-1737. DOI: 10.1111/sms.14423. Epub 2023 Jun 6. PMID: 37278319.

Image credit: © Paralympics GB