Abstract
[Purpose] The purpose of this study was to examine the effects of ankle exercises on balance ability when using shoe height insoles. [Subjects and Methods] Thirty adults in their 20s, who were students, were randomly divided into an experimental group and a control group (n=15/group). Individuals in the experimental group wore height-adjustable silicon insoles measuring 3, 5, and 7 cm three times per week for four weeks. The ankle exercise program consisted of stretching exercises, resistance training, and a balance exercise. [Results] There was a significant improvement in the balance ability of the experimental group for all height insoles (3, 5, and 7 cm) following the exercise program, as compared with before the exercise program. There was no significant improvement in the balance ability of the control group for all height insoles following the exercise program as compared with before the exercise program. The experimental group exhibited a significant improvement in balance ability following the exercise program for all the height insoles as compared with the control group. [Conclusion] According to the results of this study, active ankle exercises are helpful in preventing ankle joint damage, as they improve balance ability.
Key words: Insole, Balance, Ankle joint exercise
INTRODUCTION
Young people typically use shoe height-increasing insoles to appear taller. Height insoles are also used to counteract foot deformities and enhance balance; however, there is little evidence of the beneficial effects of height insoles1). Furthermore, since insoles alter the plantar pressure distribution, improper use of insoles can cause deformities in a normal foot2). Height insoles also retain the ankles in a plantar flexion position, which places the mechanical state of the ankles in the open-packed position and can have negative effects on balance ability3, 4). It has been demonstrated that wearing shoes height insoles or a high-heeled shoe affects balance ability5,6,7,8). Previous studies have also reported on the effects of ankle exercises on balance ability9,10,11); however, these studies focused on alterations in balance ability while wearing height insoles, after performing ankle exercises in bare feet, or while wearing shoes with low heels. The present study examined the effects of ankle exercises on improving the balance ability of an individual wearing height-increasing insoles.
SUBJECTS AND METHODS
Thirty adults in their 20s who were students at Youngdong University in North Chungcheong Province, South Korea, participated in the present study. Participants were randomly chosen from a cohort of individuals who did not exhibit skeletomuscular or neurological disorders, and they were randomly divided into experimental and control groups (n=15/group). The average age, height, and weight of the experimental group were 20.86 ± 1.35 years, 174.75 ± 4.34 cm, and 67.13 ± 9.54 kg, respectively. Those of the control group were 21.46 ± 1.55 years, 174.71 ± 4.89 cm, and 71.07 ± 12.11 kg, respectively. There were no significant differences between the two groups (p>0.05). Ethical approval for the present study was granted by the Institutional Review Board of Youngdong University. All subjects were informed of the objectives and methods of the study beforehand and gave informed consent to participate in the experiments.
Height-adjustable silicon insoles measuring 3, 5, and 7 cm were used. The experimental group participated in a total of 12 sessions of an exercise program, which was performed three times per week for four weeks. The program consisted of stretching exercises, resistance training, and a balance exercise. The stretching exercises involved four stretching routines: (i) plantar flexion active stretches, (ii) dorsiflexion active stretches, (iii) a stretch that involved tracing letters in the air with the foot while in a prone position with the leg on a pillow, and (iv) a calf muscle stretch with one leg forward and the other back whist bending the upper body forward and keeping both heels on the ground.
Stretching was performed, alternating between legs, for three 30-s sets with a break of 15 s between the sets. Stretching exercises were followed by a 1 min break, after which resistance training was performed. Resistance training routines consisted of, (i) performing plantar flexion, dorsiflexion, inversion, and eversion in a prone position while changing the position of a TheraBand™, which was anchored to a sturdy object and wrapped around the foot; (ii) using the foot to pick up a towel while seated; and (iii) heel raise exercises in a standing position. Resistance training was performed, alternating between legs, for three 20-s sets with a break of 15 s between the sets. Resistance training was followed by a 1 min break, after which the balance exercise was performed. For the balance exercise, subjects were asked to stand on one leg on an air cushion for 1 min. While they could use the wall for support if required, participants were encouraged to stand on the cushion without support. The balance exercise was performed, alternating between legs, for three 1-min sets with a break of 15 s between the sets. A Biodex Balance System™ was used to assess the balance ability of all 30 subjects in order to determine how height-increasing insoles affected the balance ability with and without ankle exercises. Subjects were asked to stand on one leg on the platform of the Biodex Balance System™ for 30 s whilst wearing a blindfold and crossing both arms, with both hands placed on the shoulders. Balance ability was assessed three times, once before the exercise program and twice after the exercise program.
An independent t-test was performed to compare the balance ability of the experimental group with that of the control group. A paired t-test was used to investigate alterations in the balance ability of each group before and after the intervention.
RESULTS
A significant improvement was detected in the balance ability of the experimental group in all height-increasing insole subgroups (3, 5, and 7 cm) after the exercise program as compared with before the exercise program (p<0.05). There was no significant improvement in the balance ability of the control group in any of the height insole subgroups (3, 5 and, and 7 cm) after the exercise program as compared with before the exercise program (p>0.05). The experimental group exhibited a significant improvement in balance ability following the exercise program for all the height insoles as compared with the control group (p<0.05; Table 1).
Table 1. Changes in group-specific interventions before comparisons between groups after the intervention (unit: score).
| Mean ± SD | |||
|---|---|---|---|
| Exercise group | Control group | ||
| 3 cm | Pre | 5.50 ± 1.28 | 6.04 ± 1.46 |
| Post† | 3.80 ± 0.88 | 5.85 ± 0.87 | |
| Difference† | 1.70 ± 1.10** | 0.18 ± 1.43 | |
| 5 cm | Pre | 5.65 ± 1.34 | 5.49 ± 1.21 |
| Post† | 3.53 ± 0.87 | 5.72 ± 1.20 | |
| Difference† | 2.11 ± 1.11** | −0.12 ± 1.23 | |
| 7 cm | Pre | 5.73 ± 1.37 | 5.59 ± 1.45 |
| Post† | 3.63 ± 0.98 | 5.89 ± 1.42 | |
| Difference† | 2.10 ± 1.33** | −0.30 ± 1.32 | |
*Pre-post paired t-test: *p<0.05; **p<0.01. †Exercise group-control group independent t-test: p<0.01
DISCUSSION
The present study examined the effects of ankle exercises on improving the balance ability of individuals wearing height-increasing insoles. Height-adjustable silicon insoles measuring 3, 5, and 7 cm were used. A height-increasing shoe insole between 3 and 5 cm was found to be ideal, whereas a shoe insole measuring >5 cm could excessively shift the plantar pressure to the front of the foot12). Although individuals endeavor to be healthy, occasionally they put beauty before health2). For example, individuals wear height-increasing shoe insoles despite knowing that wearing these insoles may decrease their balance ability. Reduced balance ability can lead to ankle joint damage, which may result in a chronic disease that ultimately undermines the individual’s quality of life13). Although it is important to recommend that individuals refrain from wearing height-increasing shoe insoles, it is also important that individuals who do wear these insoles wear them correctly and identify, develop, and perform exercises that can help maintain or improve balance ability. According to the results of the present study, active ankle exercises may be helpful in preventing ankle joint damage, as they improve balance ability. These findings may also be applied to people who wear high-heeled shoes. While the present study focused on young adults in their 20s high-heeled shoes are worn by people across the age spectrum. The present study was unable to determine which of the three exercises (stretching, resistance training, and balance exercises), contributed the most to the improvement in balance ability. In order to fully elucidate the effect of ankle exercises on balance ability, future studies should focus on how diverse age groups, different shoe types, and more specialized exercise programs affect balance ability.
REFERENCES
- 1.Urabe Y, Maeda N, Kato S, et al. : Effect of shoe insole for prevention and treatment of lower extremity injuries. JPFSM, 2014, 3: 385–398. [Google Scholar]
- 2.Shim JM, Kim HH: The effect of insole height on foot pressure of adult males in twenties. J Phys Ther Sci, 2011, 23: 761–763. [Google Scholar]
- 3.Ahn CS, Kim HS, Kim MC: The effect of the EMG activity of the lower leg with dynamic balance of the recreational athletes with functional ankle instability. J Phys Ther Sci, 2011, 23: 579–583. [Google Scholar]
- 4.Magee: DJ: Orthopedic physical assessment. Elsevier Health Sciences, 2014, pp 844–939. [Google Scholar]
- 5.Horak FB, Shupert CL, Mirka A: Components of postural dyscontrol in the elderly: a review. Neurobiol Aging, 1989, 10: 727–738. [DOI] [PubMed] [Google Scholar]
- 6.Oh MH, Lee JH, Kwon YJ, et al. : Effect of heel-heights of insole on balance in healthy adults. J Korean Soc Phys Med, 2009, 4: 79–86. [Google Scholar]
- 7.Kobayashi M, Shimizu Y: Effect of a foot insole on standing balance —biomechanical study of the plantar arch function—. Rigakuryoho Kagaku, 2014, 29: 605–607. [Google Scholar]
- 8.Christovão TC, Neto HP, Grecco LA, et al. : Effect of different insoles on postural balance: a systematic review. J Phys Ther Sci, 2013, 25: 1353–1356. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Cho BJ, Ko TS, Lee DG: Effect of ankle joint mobilization on range of motion and functional balance of elderly adults. J Phys Ther Sci, 2012, 24: 331–333. [Google Scholar]
- 10.Lee WH: The influence of ankle strategy exercise on equilibrium ability in women of octogenarians. KAPTS, 2010, 17: 67–76. [Google Scholar]
- 11.Jo SH, Kim CY: The influences of the intensive ankle joint strategy training on the muscular strength and balancing ability in the elderly women. JKAIS, 2012, 13: 5909–5919. [Google Scholar]
- 12.Lee JS, Kim DH, Jung BW, et al. : The effects of the height and the quality of the material of popular heel-up insole on the mean plantar foot pressure during walking. KJSB, 2011, (4): 479–486. [Google Scholar]
- 13.Garn SN, Newton RA: Kinesthetic awareness in subjects with multiple ankle sprains. Phys Ther, 1988, 68: 1667–1671. [DOI] [PubMed] [Google Scholar]