Dual Task During Resistance Training in Patients With Carpal Tunnel Release

Carpal tunnel syndrome (CTS) is a highly prevalent peripheral compressive neuropathy of the upper extremity. CTS is characterised by the presence of pain, tingling sensations and paraesthesia in the median nerve territory. Symptom severity and pain are commonly modulated by psychosocial factors (e.g. catastrophic thinking and kinesiophobia).

The objective of this study will be (1) to evaluate the effect of dual-task on the maximum number of repetitions possible and pain during rubber band training in patients with carpal tunnel syndrome undergoing surgery; (2) to determine the influence of psychosocial factors on the response to dual-task exercise.

Patients will voluntarily participate in the study, which will be conducted at the Hospital Clínico Universitario de Valencia, during the months of November 2022 to December 2022. All participants will be informed of the aims and content of the research and written informed consent will be obtained. The study will conform to the Declaration of Helsinki and will be approved by the local ethics committee.

The experimental protocol begins with the assessment of self-perceived pain intensity and perceived exertion when using different intensities of elastic resistance, during wrist flexion and extension, at a controlled speed of 1.5sec/ phase. To assess the intensity at which they will work, participants will perform 2 repetitions and will be allowed a rest of 60s between sets until they obtain a score of 3 on the Borg CR10 scale. For this purpose, 1.5 m long elastic bands, pre-stretched to approximately 25% of their initial length, in yellow, red, green, blue, black, silver and gold (TheraBand CLX, The Hygenic Corporation, Akron, OH, USA), will be progressively used starting from the lowest available elastic resistance (i.e. yellow). This intensity is selected because it appears to correspond to a resistance equivalent to 30% of 1RM and is considered a light intensity. Exercises should be performed with the subject's available ROM. Participants are asked to move their body and trunk as little as possible and to perform the exercise smoothly, without stopping or accelerating. The exercise will be performed in a seated position, with the back supported by the backrest and the forearm resting on a table, with the shoulders and elbows bent at 90 grades, leaving the wrist free, with the elastic bands held under the feet (stepping on them).

During the week of familiarisation and analysis of acute effects, subjects will attend 2 sessions, separated by 2 rest days in between, where they will perform 2 conditions/session (4 conditions in total at the end of the study), in a counterbalanced manner, with 10 minutes rest between each condition: 1) perform the highest number of wrist flexion repetitions with the appropriate resistance; 2) perform the highest number of wrist flexion repetitions with the appropriate band, and following a dual task; 3) perform the highest number of wrist extension repetitions with the appropriate band; 4) perform the highest number of wrist extension repetitions with the appropriate band, and following a dual task.

The dual task will be self-regulated and will consist of subtracting 3 by 3 from 100, and performing the maximum number of repetitions possible. The subject will perform the mathematical operation aloud, without being corrected, but if they get stuck on a number or operation, they will have to be told to continue subtracting from that number or from another, so that they do not stop performing the operations. At the end of each condition, the subject will be asked about the perceived difficulty of the self-regulated mathematical task (where 0 is not difficult at all and 10 is the maximum difficulty), and the maximum number of repetitions performed will be recorded. The pressure points and VAS will then be measured again.

After the familiarisation week and the analysis of acute effects, subjects will be randomly distributed into two conditions: 1) exercise with dual task; 2) exercise without dual task. The exercises performed will be the same as during the familiarisation week, as well as the guidelines for performing them. Each condition shall be evaluated with a time-out (Crossover design).