Muscle strength parameters of the throwing and non-throwing upper limb in international Boccia players with cerebral palsy

The ratings included in the ranking process are aimed at ensuring fair play throughout the competition. Because the sport requires precise throwing technique, where the player must be fast and strong to perform a successful throw, it is presumed that upper extremity strength is involved in the players' ability to succeed. Therefore, the aim of the study is to determine the muscle strength parameters of the upper extremity of Boccia players with CP.

Executive Summary
Bocce is a Paralympic sport, similar to pétanque, played nationally and internationally by disabled athletes who require a wheelchair due to a disability, since 1984. As it is designed for athletes with severe physical impairments, it uses a meticulous sports medical classification system to ensure fair competition. This ranking process ensures that victory is determined by players' skills, power, stamina, tactical ability and mental focus. After the ranking process, players are ranked into one of four categories, from BC1 to BC4.

Context and Justification
All players with Cerebral Palsy (CP) are classified as either BC1 or BC2, depending on the need for assistance throughout the competition. The assessment of players with PC includes several medical tests, depending on the type of motor disorder. It may include the assessment of spasticity, dystonia, dyskinesia or ataxia, among others. The rules for classification have been defined by the BISFed Rules Committee.

Given the nature of the sport, as it involves throwing balls to reach the ball jack, it is presumed that upper extremity strength may influence the ability to succeed in the sport. As previously stated by Kataoka et al., players who have a stronger throw are better able to be more accurate in their throw during competition. In addition, Boccia players need to throw far and fast to succeed in the competition.

For these reasons, it is presumed that an accurate, long and fast throw may be influenced by the ability of the upper limb to perform a good throw. Although the assessment of upper extremity strength has been widely defined in different studies, upper extremity muscle strength parameters of Boccia players have never been studied before.

General Objective
The aim of this study is to determine the muscle strength parameters of the upper limbs of Boccia players classified in BC1 and BC2. To describe the maximum grip strength (MGS) of the throwing and non-throwing upper extremity of international boccia players with cerebral palsy.

Specific Objectives
To describe Isometric Arm Strength (IAS), Grip Muscle Endurance (GME) and Pinch Strength (PS) of the throwing and non-throwing upper extremity of International Bocce Players with Cerebral Palsy.
Determine the differences in MGS, GME, PS and IAS between Boccia players classified in classes 1 and 2.

All assessment will be done in one session. After the evaluation of the Competition Classification has been carried out, the subjects included in this study will be evaluated in order to obtain all the relevant data for the study.

Then, some evaluations will be carried out by the examiner, and with the assistant. All procedures are based on aliens. Beforehand, the order of measurements will be pre-randomized using the random.org app (mobile app software). All assessments will be performed for both upper limbs.

Isometric Arm Strength (IAS)
The maximum capacity of different muscle groups to exert a force will be assessed using a MicroFET 2 Hand-Held Dynamometer (HHD). Subjects will be asked to perform a maximum force isometric contraction against the examiner, for a few seconds and continue to exercise maximum efforts for 5 seconds.

Maximum Grip Strength (MGS)
For the maximum capacity of the different muscle groups to exert a force, the participants will be seated with their forearms supported, with a 90º elbow bend and the wrist in a neutral position. Participants will be instructed to exert maximal force on the handle of the dynamometer for approximately 5 seconds, with 3 measurements taken for both hands and a 30-second rest between trials.

Grip Muscle Endurance (GME)
Maximal isometric contraction will be assessed over a 20-second period by asking subjects to perform a maximal contraction following an audible signal, for the time period described. This test will only be performed once per hand.

Pinch Strength (PS)
The maximum capacity of the index-thumb pinch to exert a force will be evaluated using an electronic "pinch grip" dynamometer. The participants will be seated with their forearms supported, with a 90º elbow bend and the wrist in a neutral position. Participants will be instructed to exert maximal force, using a side pinch, on the handle of the dynamometer for approximately 5 seconds, with 3 measurements taken for both hands and a 30-second rest between trials.