Does short term upper limb immobilization affect inter-limb transfer of sequence-specific motor skill?
Krakovski, Maria A.
MetadataShow full item record
Previous research has demonstrated that short-term limb immobilization leads to a decrease in corticospinal excitability and a subsequent increase in the capacity for long term potentiation, the neural mechanism underlying learning. Whether immobilization directly leads to the enhancement of motor learning is currently unknown. Moreover, the effect of short-term immobilization on the inter-limb transfer of motor skill has not been quantified. Interlimb transfer refers to skill improvement in one limb being followed by skill gain in the opposite, untrained limb providing an index of skill generalization to the untrained limb. Understanding inter-limb skill transfer could lead to enhanced motor skill learning in health and disease. The present study aims to train an implicit sequence on the left hand and assess motor skill performance in the untrained, right hand of individuals at baseline (AM) and during a follow-up assessment (PM). Thirty-six young, healthy participants were randomly assigned to a motor skill training condition (left hand trained or left hand untrained) in the morning (AM) followed by an immobilization condition (immobilized or non-immobilized between sessions) then follow-up testing in the evening (PM). Trained participants completed a single training session using a modified serial reaction time task containing an embedded repeating sequence. Untrained participants completed short skill test blocks before the immobilization period but did not undergo the left-hand training paradigm in the morning. In all participants, general motor performance and sequence-specific performance were compared in the AM and PM sessions. Results showed AM to PM improvement in general skill performance in the Trained-Immobilized group (p=0.045) but a decrease in sequence-specific task performance in all groups. It can be suggested that immobilization enhanced the capacity of general motor learning and led to the inter-limb transfer of non-sequence-specific general motor skill.