Asymmetric effector transfer of complex movement sequences.

Area of Science:

• Motor control and learning
• Biomechanics
• Human movement science

Background:

• Previous studies observed effector transfer profiles in multi-element movement sequences.
• The impact of external load on these transfer profiles was not fully understood.

Purpose of the Study:

• To investigate how adding external load affects effector transfer profiles in multi-element movement sequences.
• To compare motor learning and transfer between dominant and non-dominant limbs.

Main Methods:

• Participants practiced a 16-target lever movement sequence with either their dominant (right) or non-dominant (left) limb under a 0.567kg load.
• Testing occurred 24 hours later with loads of 0kg, 0.567kg, and 1.134kg, using both practiced and unpracticed limbs.

Main Results:

• External loads (0kg, 0.567kg, 1.134kg) had minimal impact on overall test performance.
• The left-limb trained group performed equally well with the right limb, but the right-limb trained group was slower when transferring to the left limb.
• The left-limb trained group maintained practiced element durations during transfer, while the right-limb trained group showed disruptions in faster element durations when transferring to the left limb.

Conclusions:

• Motor sequence transfer from the non-dominant to the dominant limb is more robust than the reverse.
• Poor right-to-left limb transfer may stem from difficulties in accessing appropriate motor commands or controller limitations in managing movement dynamics for sequence execution.