The effects of tongue stretching exercise on tongue length in healthy adults: a preliminary study (2024)

Abstract

[Purpose] The purpose of this study was to investigate the effects of tongue stretchingexercise on the tongue length of healthy adults. [Subjects and Methods] This studyrecruited 6 healthy adults. They were treated for 4 weeks with tongue stretching. Thechange in tongue length during tongue protrusion before and after intervention wasmeasured using a ruler. [Results] All 6 participants showed increased tongue length(minimum 20 mm to maximum 40 mm). [Conclusion] This study confirms that tongue stretchingis a useful method to increase tongue length.

Keywords: Tongue, Stretching, Swallowing

INTRODUCTION

The tongue is one of the structures that plays an important role in the normal swallowingmechanism. Therefore, maintaining proper tongue function is important for safe swallowing.With this in mind, the proper muscle strength and range of motion of the tongue areimportant for its adequate functioning in the oral phase. Park et al.¹⁾ have reported that tongue strength is closely related to theoropharyngeal swallow function. Moreover, the strength of the tongue can be maintained orincreased through strength training, such as resistance exercise. Kim et al.²⁾ have shown that tongue strength training iseffective in improving swallowing as well as in increasing tongue strength. However, mostreported studies have been conducted on tongue strength training. Therefore, there are fewstudies on interventions for increasing the range of motion of the tongue. This studyinvestigated the effects of tongue stretching training on the length of the tongue duringtongue protrusion in healthy adults.

SUBJECTS AND METHODS

This study was conducted on 6 healthy adults (3 men, 3 women; age range, 21–25 years). Theparticipants were all healthy volunteers with no reported neurologic or structural damageaffecting their oropharyngeal swallowing functions. The study purpose was explained to theparticipants before enrollment, and informed consent for participation was obtained from allparticipants in accordance with the principles of the Declaration of Helsinki.

In this study, the tongue stretching method used was as follows: the participant was askedto sit comfortably in a chair and allow his or her tongue to protrude as much as possible.At this time, the intervenor used dry gauze to grasp the tongue tightly with both hands andpull. The pull intensity was painless, and the tongue was pulled to the end of the range ina way that the tongue could be stretched to the maximum. The intervention period was 4weeks, 5 days a week, 30 times a day. The measurement site was measured from the center ofupper lip to the tip of the tongue out of the lips during tongue protrusion³⁾.

RESULTS

As a result of measuring the change in tongue length during tongue protrusion, participant1’s tongue length increased from 310 mm to 340 mm, participant 2’s tongue length increasedfrom 280 mm to 320 mm, participant 3′s tongue length increased from 300 mm to 320 mm,participant 4’s tongue length increased from 360 mm to 390 mm, participant 5′s tongue lengthincreased from 330 mm to 350 mm, and participant 6’s tongue length increased from 250 mm to270 mm.

DISCUSSION

All participants in this study showed increased tongue length during tongue protrusionfollowing the intervention of tongue stretching. Stretching is known to relieve musculartension, stretch length, and relax⁴⁾. Withregards to static stretching, the increased range of motion following a single exercise canbe explained by a decrease in overall muscle-tendon stiffness⁵⁾. Flexibility, which refers to the ability of a muscle to elongate,is an important component of physical fitness, and has an intimate relation with muscleperformance⁶⁾. It is believed thatstretching can decrease muscle stiffness, induce an increase in Ca⁺ within theneuromuscular junction, and promote sarcomerogenesis^7,8). All these factors may collectivelycontribute to a possible enhancement in motor performance after stretching exercise. Thistheoretical evidence supports the results of this study. Thus, tongue stretching exercisescan increase range of motion and motor performance, and tongue stretching exercises can helppatients with dysphagia.

REFERENCES