Can Mental Practice Increase Ankle Dorsiflexor Torque?

Abstract

Background and Purpose. Mental practice has been shown to be effective in increasing the force production of the abductor digiti minimi muscle in the hand. The aim of this study was to determine whether mental practice could produce strength gains in the larger ankle dorsiflexor muscles, which are important during walking. Subjects. Twenty-four subjects were randomly assigned to a physical practice group, a mental practice group, or a control group (8 subjects per group). Methods. In the practice groups, subjects either physically or mentally practiced producing maximal isometric contractions for 3 sets of 10 repetitions, 3 times per week for 4 weeks. Changes in mean peak isometric torque normalized to body weight and the resulting percentage of improvement were analyzed across the 3 groups. Results. Differences in raw torque production after training in the 2 practice groups resulted in significant percentages of improvement for the physical practice group (25.28%) and the mental practice group (17.13%), but not for the control group (−1.77%). The 2 practice groups were not statistically different in their maximal torque-generating capacity after training. Discussion and Conclusion. These findings show that mental practice in people without impairments can lead to an increase in torque production similar to that produced by physical practice. Such a technique may prove to be a useful adjunct to traditional treatment options aimed at increasing muscle strength.

Selective muscle contraction during plantarflexion is incompatible with maximal voluntary torque assessment

“…Without training or adequate testing conditions, plantarflexor muscles are not maximally activated by volition, and only reach about 80-90% of voluntary activation (Cresswell et al 1995;Maffiuletti et al 2002). This is in line with the finding that the neural drive to these muscles can be significantly improved by a strength training (Shield and Zhou 2004) or imagined strength training (Zijdewind et al 2003;Sidaway and Trzaska 2005), whereas such is not the case for the elbow flexors, for example which possess a high initial level of voluntary 20 activation (Herbert et al 1998). The work of Devanne and collaborators (Devanne et al 2002;Kouchtir-Devanne et al 2012) is particularly interesting in this respect.…”

The effects of modified constraint-induced therapy combined with mental practice on patients with chronic stroke

“…The same muscular 2 , 3 , 4 ) and neural structures 5 , 6 ) subserve both physical and mental practice, enabling MP to offer similar benefits to rehabilitation in patients with stroke. For example, MP can be used as a method of acquiring additional practice attempts in rehabilitation settings 7 , 8 , 9 ) , especially when physical activity is not possible due to severe impairment 10 ) . In stroke rehabilitation settings, the addition of MP to repetitive, task-oriented training regimens significantly increases affected arm use 11 ) and function in subacute 12 , 13 ) and chronic patients 11 ) , and this was also reported in a recent, randomized controlled trial 14 ) .…”

Motor imagery muscle contraction strength influences spinal motor neuron excitability and cardiac sympathetic nerve activity

“…In recent years, the effectiveness of MI has been recognized in rehabilitation. MI can improve various motor functions such as muscle strength 2 , 3 , 4 ) and range of motion 5 ) . When MI is used in rehabilitation to improve motor function, it has the potential to increase both central and spinal neural functions.…”