Optimising classification of proximal arm strength impairment in wheelchair rugby.

Introduction:

Within WR, substantial research has been conducted to establish and validate the four trunk scores for athletes of all eligible impairment types. Yet, upper extremity impairment testing is limited to strength impairment only and the scores allocated are not supported by research and remain expert opinion-based, rather than evidence-based.

Upper extremity strength impairment can be classed as either proximal or distal weakness in WR athletes depending on the level of the spinal lesion and the resulting muscles innervated.

 Unfortunately, no tests exist to quantify either distal impairments to the upper extremities or aspects of ball handling performance specific to WR. However, a series of isometric strength tests that were objective, reliable, ratio-scaled, and valid for the assessment of proximal upper extremity strength impairment in WR players have recently been developed.

Study aim:

1) To explore the relationship between proximal arm strength impairment and linear mobility performance in highly trained WR athletes using isometric strength test.

2) To explore whether a valid classification structure could be produced via cluster analyses of the strength data and to compare this structure to the current IWRF system for classifying proximal arm strength impairment.

Methods:

Fifty-seven trained WR athletes with strength impaired arms and no trunk function performed six upper body isometric strength tests and three 10 m sprints.

Two further multi-joint tests were also incorporated to assess athlete’s capacity to isometrically “push” and “pull” their wheelchair. Athletes performed all testing in their own rugby wheelchairs with the gloves, tape and strapping that they use for competition.

Wireless timing gates were positioned at 2 m and 10 m to assess acceleration and sprinting performance.

Main findings:

• Significant correlations were identified between all measures of isometric strength and performance.
• All tests of proximal arm strength impairment were significantly correlated to performance specific to WR and were stronger for 10m times (moderate to high) than 2m times (low to high).
• Stronger relationships to performance were identified for shoulder flexion and elbow extension compared to other strength measures.
• The existing system used by the IWRF to classify proximal arm strength impairments was a reasonably valid system.

Reference:

Mason BS, Altmann VC, Hutchinson MJ, Petrone N, Bettella F, Goosey-Tolfrey VL. Optimising classification of proximal arm strength impairment in wheelchair rugby: A proof of concept study. J Sports Sci. 2021 Aug;39(sup1):132-139. DOI: 10.1080/02640414.2021.1883291. Epub 2021 Feb 4. PMID: 33541213.

Image credit: © Paralympics GB