Enhancing prehension strength and dexterity through cross-education effects in the elderly

Abstract

Cross-education, the enhancement of an untrained limb following training of the opposite limb, encompasses both strength and dexterity-a vital factor in daily activities. In the elderly, where both strength and dexterity decline, investigating the simultaneous transfer of these attributes through motor training is crucial. This study explored the effects of a novel hand training program on prehension strength and hand dexterity in the elderly (> 65 years). Maximum Grasping Force (MGF), Jebsen-Taylor hand function test, and Purdue Pegboard test were measured. Training, focusing on 20% sub-maximal force control, occurred thrice weekly for five weeks. Post-training, improvements were observed in both MGF and hand function in both hands, indicating the efficacy of the program. Simultaneous inter-limb transfer effects in strength and dexterity support the potential of cross-education for hand rehabilitation in elderly or hemiparetic patients. This study contributes insights into optimizing interventions for enhancing strength and dexterity in the elderly.

Fig. 1

The experimental settings for both groups. (A) Five sensors were attached to a grip type device. The participant holds a handle with individual fingers positioned on each sensor. (B) The participant measures the Maximum grasping force of dominant and non-dominant hand using a device. (C) The set-up for the Game-Based Grasping Training for the dominant hand. The hand, wrist and forearm were immobilized with a band. The participant watched the computer screen to perform a task while sitting in a chair. (D) The experiment process flow chart. Participants performed tests three times before training, post-test after 5 weeks, and retention- test after 2 weeks. All tests included MGF and two clinical tests (i.e., Jebsen–Taylor hand function test and Purdue Pegboard test). Drawn using Poser Pro 11 (www.posersoftware.com) and Microsoft Office 2019 (www.microsoft.com).

Fig. 2

The results of prehension strength test for the training and control group. (A) Maximal Grasping Force (MGF) values in the dominant hand during pre-, post-, and retention- test. (B) MGF values in the non-dominant hand during the pre-, post-, and retention- test. The black dots represent the training group, and the empty dots represent the control group. All the MGF results were represented as normalized data by calculating the values relative to the mean values obtained in the pre-test (MGF_NORM). *signifies significant (p < 0.05) differences in MGF among the tests.

Fig. 3

The results of manual dexterity for the training and control group. (A) Jebsen Taylor Hand Function Test (JT) scores in the dominant hand during the pre-, post-, and retention-test. (B) JT scores in the non-dominant hand during the pre-, post-, and retention- test. The black dots represent the training group, and the empty dots represent the control group. All the JT results were represented as normalized data by calculating the values relative to the mean values obtained in the pre-test (JT (score)_NORM). *signifies significant (p < 0.05) differences in JT values among the tests.

Fig. 4

The results of manual dexterity for the training and control group. (A) Peg Board test (PB) scores in the dominant hand during the pre-, post-, and retention- test. (B) PB scores in the non-dominant hand during the pre-, post-, and retention- test. The black dots represent the training group, and the empty dots represent the control group. All the JT results were represented as normalized data by calculating the values relative to the mean values obtained in the pre-test (PB (ea)_NORM). *Signifies significant (p < 0.05) differences in PB scores among the tests.