Isotonic resistance jaw exercise alters jaw muscle coordination during jaw movements

Abstract

The aim was to investigate the effects of isotonic resistance exercise on the electro-myographic (EMG) activity of the jaw muscles during standardised jaw movements. In 12 asymptomatic adults surface EMG activity was recorded from the anterior temporalis and masseter muscles bilaterally and the right anterior digastric muscle during right lateral jaw movements that tracked a target. Participants were randomly assigned to a Control group or an Exercise group. Jaw movement and EMG activity were collected (i) at baseline, before the exercise task (pre-exercise); (ii) immediately after the exercise task (isotonic resistance at 60% MVC against right lateral jaw movements); (iii) after 4 weeks of a home-based exercise programme; and, (iv) at 8-weeks follow-up. There were no significant within-subject or between-group differences in the velocity and amplitude of the right lateral jaw movements either within or between data collection sessions (P > 0.05). However, over the 8 weeks of the study, three of the tested EMG variables (EMG Duration, Time to Peak EMG from EMG Onset, and Time to Peak EMG activity relative to Movement Onset) showed significant (P < 0.05) differences in the five tested muscles. Many of the significant changes occurred in the Control group, while the Exercise group tended to maintain the majority of the tested variables at pre-exercise baseline values. The data suggest a level of variability between recording sessions in the recruitment patterns of some of the muscles of mastication for the production of the same right lateral jaw movement and that isotonic resistance exercise may reduce this variability.

Effects of exercise therapy on painful temporomandibular disorders

“…According to a past study, around 30% of university students had self report of TMD symptoms in Japan . In the last decade, research on TMD has provided multiple treatment options such as medication, occlusal splints, cognitive behavioural therapy and exercise therapy to manage pain in masticatory muscles and temporomandibular joints . Among these treatment options, this review focused on exercise therapy which is widely used for management of OFP including painful TMD conditions and is a good option due to its low invasive character and economical effectiveness.…”

Does the habitual mastication side impact jaw muscle activity?

“…Although at present few studies take mastication side preference into account (Rahal & Goffi-Gomez, 2009), it may well be an important factor, because the recruitment patterns of some mastication muscles can vary for the production of the same jaw movement, and isotonic exercise may reduce this variability (Wirianski et al, 2014). It is possible that mastication plays a role in these patterns.…”

Neurophysiological aspects of isotonic exercises in temporomandibular joint dysfunction syndrome

“…In association with orientation, exercises, and rehabilitation of the stomatognathic functions, improvements were noted in volunteers with TMD versus the control group after the use of occlusal splints (9) . On the contrary, Wirianski et al (10) detected no differences between the control and intervention groups after isotonic resistance exercise. One of the limitations of this study was intra-subject variability during the primary outcome evaluation.…”

“…Most of results showned by relaxation exercises, home orientations are measure by clinical outcomes (5,(7)(8)(9)(10) . In addition to that, complementary exams enable the objective measurement of subjective issues such as pain (11) .…”