Influence of the type of training task on intermanual transfer effects in upper-limb prosthesis training: A randomized pre-posttest study

Abstract

Intermanual transfer, the transfer of motor skills from the trained hand to the untrained hand, can be used to train upper limb prosthesis skills. The aim of this study was to determine the relation between the magnitude of the intermanual transfer effect and the type of training task. The used tasks were based on different aspects of prosthetic handling: reaching, grasping, grip-force production and functional tasks. A single-blinded clinical trial, with a pre-posttest design was executed. Seventy-one able-bodied, right-handed participants were randomly assigned to four training and two control groups. The training groups performed a training program with an upper-limb prosthesis simulator. One control group performed a sham training (a dummy training without the prosthesis simulator) and another control group received no training at all. The training groups and sham group trained on five consecutive days. To determine the improvement in skills, a test was administered before, immediately after, and one week after the training. Training was performed with the ‘unaffected’ arm; tests were performed with the ‘affected’ arm, with the latter resembling the amputated limb. In this study half of the participants trained with the dominant hand, while the other half trained with the non-dominant hand. Participants executed four tests that corresponded to the different training tasks. The tests measured the reaching (movement time and symmetry ratio), grasping (opening time, duration of maximum hand opening, and closing time), grip-force production (deviation of asked grip-force) and functional (movement time) performance. Half of the participants were tested with their dominant arm and half of the participants with their non-dominant arm. Intermanual transfer effects were not found for reaching, grasping or functional tasks. However, we did find intermanual transfer effects for grip-force production tasks. Possibly, the study design contributed to the negative results due to the duration of the training sessions and test sessions. The positive results of the grip-force production might be an effect of the specificity of the training, that was totally focused on training grip-force production. When using intermanual transfer training in novice amputees, specific training should be devoted to grip-force.

Intermanual transfer of visuomotor adaptation is related to awareness

“…This holds for elite athletes, but it is also true for recreational sports and also has implications for rehabilitation. In rehabilitation, the transfer of motor skills from the trained to the untrained arm can be useful in the therapy of brain-lesioned patients [1] or in upper-limb prosthesis training [2–4].…”

Intermanual Transfer Effects on Performance Gain Following Dominant Hand Training in Community-Dwelling Healthy Adults: A Preliminary Study

“… 14 Additionally, intermanual transfer training can be used to train prosthetic limbs in people with amputation. 15 Individuals with amputated upper or lower limbs often start learning prosthetic skills after getting the prosthesis. However, they could start the prosthetic training immediately after the amputation using the intermanual transfer, so that training of the unaffected limb could enhance the prosthetic skills of the affected limb.…”

“…14 This is also known as intermanual transfer of training. 15 Motor learning is a continuous process, which starts with an acquisition of a task and progresses with the transfer of the task. 16 Previous studies have suggested that variability in task and strength training could facilitate the intermanual transfer of motor learning.…”

Martial arts training is related to implicit intermanual transfer of visuomotor adaptation

“…There are good reasons for studying the generalization of motor learning from one arm to the other, untrained arm. On a behavioral level, understanding the mechanisms of intermanual transfer can help athletes and coaches design effective training measures (Haaland & Hoff, 2003) or it can be useful in upper-limb prosthesis training (Romkema et al, 2017). On a neuronal level, the study of intermanual transfer can broaden our knowledge about hemispheric interactions (Chase & Seidler, 2008) or it can unveil both the global and the local nature of internal representations of motor learning (Harris, 1963;Lefumat et al, 2015).…”