Disuse Atrophy, Immobilization
Conditions
Keywords
Cross-education, Immobilization, contralateral training, interlimb transfer
Brief summary
This randomized controlled trial aims to compare manual dexterity and strength between a group undergoing a contralateral manual dexterity training program and a no-intervention control group in healthy, physically inactive individuals subjected to an induced upper-limb disuse model.
Detailed description
Cross-education of skill offers promising opportunities for the rehabilitation of upper-limb musculoskeletal injuries. An approach based on contralateral manual dexterity training could accelerate functional recovery, reduce motor skill loss during periods of immobilization, and optimize conventional rehabilitation protocols. However, controlled studies are needed to analyze the efficacy of specific unilateral training protocols designed to maximize cross-education before clinical translation. To date, no experimental studies have been published on healthy individuals subjected to upper-limb disuse models alongside contralateral skill training involving functional tasks. This cross-education effect could potentially prevent the loss of manual dexterity and strength that occurs during immobilization. For this research, a contralateral manual dexterity training protocol was developed based on the functional limitations commonly experienced by individuals with forearm and hand musculoskeletal injuries (e.g., distal radius fractures, wrist sprains, carpal tunnel syndrome, and tendinopathies). Additionally, the protocol incorporates characteristics from training programs that have demonstrated the greatest cross-education effect.
Interventions
OTHERContralateral Manual Dexterity Training
The subjects in the experimental group will perform contralateral manual dexterity training focused on moving cylinders of 0.5, 1 or 1.5 kilos with grips and movements in different planes on a gridded board. Participants will have to develop different grips and place the cylinders in the quadrants indicated on a smartphone screen.
Sponsors
Universidad Catolica de Temuco
University of Valencia
Universidad de La Frontera
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Individuals will be eligible for inclusion if they are right-handed adults aged 18 to 35 years with a body mass index (BMI) between 18.5 and 30 kg/m². * Individuals must be classified as physically inactive, defined as not meeting the World Health Organization criteria of at least 150 minutes of moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity per week.
Exclusion criteria
* Individuals who have engaged in physical training (e.g., any form of strength or aerobic exercise) or specific manual dexterity training within the past 6 months. - Individuals who regularly participate in artistic, occupational, or sporting activities requiring high levels of manual dexterity (e.g., musicians, gamers, craftspeople). * Individuals with a history of orthopedic or traumatic injuries affecting either upper extremity. Individuals with pathologies or conditions that preclude safe training (e.g., uncontrolled hypertension, or visual, auditory, or cognitive impairments \[for example, dyscalculia\]). * Individuals currently using nutritional supplements or medications that interfere with the regulation of skeletal muscle mass and strength (e.g., whey protein, creatine) or the central nervous system (e.g., antidepressants, anxiolytics, hypnotics).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Fine Manual Dexterity | Baseline and day 7 | Fine manual dexterity will be assessed using the Functional Dexterity test (FDT). Using a stopwatch, the evaluator records the total time in seconds that the participant takes to complete the task. |
| Force control | Baseline and day 7 | In a seated position with the elbow flexed, participants will perform isometric contractions to reach a target torque guided by real-time visual feedback. The accuracy of maintaining these contractions in the wrist flexor and extensor muscles will be assessed using a Humac Norm isokinetic dynamometer (Computer Sports Medicine, Inc., Stoughton, MA, USA). Participants will perform a continuous 60-second isometric contraction exercise. During this period, participants will adjust their force level to between 10% and 30% of their maximum voluntary contraction (MVC) at 10-second intervals. Three attempts will be performed per limb. The Root Mean Square Error (RMSE) will be recorded. |
| Gross Manual Dexterity | Baseline and day 7 | This gross manual dexterity will be assessed using the same task performed during the experimental group's contralateral manual dexterity training. Specifically, participants will complete 15 trials, moving cylinders of varying weights across a gridded board following a sequence displayed on a smartphone. The time required to complete these 15 trials will be recorded. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Handgrip strength | Baseline and day 7 | Maximum lumbrical and cylindrical grip strength will be assessed using a Jamar Plus+ digital hand dynamometer. The highest value from three attempts will be recorded for each assessment |
| Joint Position Sense Test | Baseline and day 7 | Proprioception: Wrist flexion-extension joint position sense will be assessed using the Joint Position Sense Test (JPST). All measurements will be conducted with a Humac Norm isokinetic dynamometer (Computer Sports Medicine, Inc., Stoughton, MA, USA). Three attempts will be made per limb. The absolute error (difference in degrees between 30° and the angle achieved during the test) will be recorded. |
| Left/right judgment | Baseline and day 7 | Left/right judgment will be assessed using the Recognise™ application (Noigroup, Adelaide, Australia). Performance on the laterality judgment task was quantified using the Inverse Efficiency Score (IES), calculated as the average reaction time of correct responses divided by the proportion of correct responses (IES = RT / PC). 3 blocks of 20 images (60 images total). Maximum exposure time: 5 seconds per image. |
Countries
Chile
Contacts
CONTACTIván A. Cuyul-Vásquez, PhD(c)
Outcome results
None listed