Search

[Purpose] The aim of this study was to examine the changes in sternocleidomastoid muscle (SCM) activity when using a cervical support pillow (CSP) and to determine the pillow's effect on satisfaction in asymptomatic participants. [Subjects and Methods] This study followed a cross-over design and the order of the measurements was counterbalanced. Twenty asymptomatic participants were positioned supine for 5 minutes by using either a CSP or a general pillow (GP) while the activity of the SCM was measured using surface electromyography. [Results] The CSP significantly decreased the activity of the SCM compared with the GP, and satisfaction after use of the CSP was significantly greater than that after use of the GP. [Conclusion] This study suggests that the CSP may be effective in preventing unnecessary neck muscle activation during sleep in asymptomatic people.

[Purpose] The aim of this study was to investigate the effect of lumbar lordosis assistive support (LLAS) on craniovertebral angle (CVA) and mechanical properties of the upper trapezius (UT) muscle in subjects with forward head posture (FHP). [Subjects and Methods] This study recruited 20 subjects with FHP. CVA and muscle tone, viscoelasticity, and stiffness of the UT were measured using Myoton in all subjects in a sitting position with LLAS and in a neutral sitting position. The order of measurements was randomized and the mean values were calculated twice. [Results] The sitting position with LLAS showed a significantly greater improvement than the neutral sitting position with regard to CVA and muscle tone, viscoelasticity, and stiffness of the UT. [Conclusion] We suggest that the sitting position using LLAS induces the maintenance of normal neck posture and a reduction in the muscle tone of the UT in the subjects with FHP.

[Purpose] This study investigated the effect of chin tuck exercise (CTE) using a neckline slimmer device on suprahyoid (SH) and sternocleidomastoid (SCM) muscle activation in healthy adults. [Subjects and Methods] We measured activation of the SH and SCM muscles using surface electromyography in 20 healthy adults during head lift exercise (HLE) and CTE using a neckline slimmer device. The order of exercises was randomized and the mean and peak values of each muscle's activation were assessed. [Results] During the CTE using a neckline slimmer device, SH activation was significantly greater and SCM activation was significantly lower than during the HLE. [Conclusion] This study suggest that chin-tuck exercise using a neckline slimmer device may be more helpful than HLE for swallowing training.

[Purpose] The purpose of the present study was to assess the relationship between age of onset and risk factors including family history and life style in Korean population with type 2 diabetes mellitus (T2D). [Subjects and Methods] Subjects with T2D patients who received outpatient care for blood sugar control were randomly sampled at 13 general hospitals and 969 subjects were included. Cox proportional hazard models were used to confirm associations between age of onset and risk factors including family history and life style in Korean population with T2D. [Results] Parent history of T2D was significantly associated with age of onset. Compared to none of family members with T2D, those whose both father and mother had a history showed the highest the risk of early-onset (HR=2.36; 95% CI=1.45-3.85). Mother and father's history of T2D (HR=1.73; 95% CI=1.46-2.05; HR=1.83; 95% CI=1.40-2.37) were associated with the risk of early-onset. Moreover, exercise (HR=1.23, CI=1.08-1.40) smoking status (HR=1.62, CI=1.32-1.99), and drinking (HR=1.32, CI=1.13-1.54) were associated with a higher risk for the early-onset. [Conclusion] Family history as well as life style including exercise, smoking, and drinking are the risk factors for early-onset factor in Korean population with T2D.

[Purpose] The purpose of this study was to establish the reliability and validity of the Korean-translated version of the Lower Limb Functional Index (LLFI) in the assessment of patients with lower-limb disorders. [Subjects and Methods] Fifty-six subjects with lower-limb disorders, 24 men and 32 women, participated in this study. Reliability was determined by using the intra-class correlation coefficient and Cronbach's α for internal consistency. Validity was examined by correlating the LLFI scores with the Lower Extremity Functional Scale (LEFS) and Short Form 36 (SF-36) scores. [Results] The test-retest reliability was 0.95. The criterion-related validity was established through a comparison with the Korean versions of the LEFS and SF-36. [Conclusion] The Korean version of the LLFI was shown to be a reliable and valid instrument for assessing lower-limb complaints.

[Purpose] This study aimed to investigate the correlation between the diaphragm thickness and diaphragm excursion, and pulmonary function in individuals with stroke. [Subjects and Methods] One hundred fourteen patients who were clinically diagnosed with ischemic or hemorrhagic stroke were included. The diaphragm thickness and excursion were assessed using ultrasonography, and the diaphragm thickening ratio was standardized using a formula. To analyze pulmonary function, we measured the forced vital capacity, forced expiratory volume in one second, and peak expiratory flow. [Results] A statistically significant correlation was found between the diaphragm thickness, thickness ratio, and diaphragm excursion; and the forced vital capacity, forced expiratory volume in one second, and peak expiratory flow. [Conclusion] This study demonstrated that there is a relationship between respiratory function and diaphragm thickness and diaphragm excursion, especially in the paretic side of the diaphragm. Therefore, the role of the respiratory muscles of the paretic side is important in rehabilitation programs to improve the respiratory function of stroke patients.

[Purpose] The purpose of this study was to investigate the effects of task-oriented training (TOT) on hand dexterity and strength in children with spastic hemiplegic cerebral palsy. [Subjects and Methods] Twelve children with spastic hemiplegic cerebral palsy were randomly assigned to either the TOT group (n=6) or the control group (n=6). In both groups, conventional occupational therapy was performed 40-min/day, 2 times a week, for 4 weeks. In the TOT group, TOT was additionally performed for 20 min, and the control group received usual care. The box and block test (BBT) was performed to assess hand dexterity. Hand strength was also assessed using hand dynamometer. [Results] After intervention, the TOT group showed a significant improvement of hand dexterity. In the control group, BBT and grip strength were not significantly improved after intervention. [Conclusion] In clinical settings, we suggest that TOT may be used as an intervention to improve hand dexterity in children with spastic hemiplegic cerebral palsy.

[Purpose] The objective of this study was to investigate the effects of spinal support device (SSD) on pain and hamstring extensibility in patients with non-specific low back pain (NSLBP). [Subjects and Methods] 20 patients with NSLBP were recruited and randomly assigned to either the SSD group or the control group. In the SSD group, SSD was applied; in the control group, bed rest in supine position was performed. Both groups underwent treatment 20 min/day, 3 times a week, for a duration of 4 weeks. To assess the hamstring extensibility, sit and reach test (SRT) was performed. To assess pain pressure threshold (PPT) of the sacroiliac joint, a pressure algometer was used. Visual analog scale (VAS) was used to quantify pain. [Results] The SSD group showed a significant improvement in sacroiliac joint pain with increased VAS, and the control group showed a significantly increased VAS after intervention. In the SSD group, VAS was significantly increased, but SRT was not changed compared with the control group. [Conclusion] These results demonstrated that an application of SSD effectively attenuates low back pain. Therefore, SSD may be a suitable intervention for pain control in patients with NSLBP.

[Purpose] The purpose of this study was to establish the reliability and validity of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) translated into Korean for use with patients' low back pain. [Subjects and Methods] Sixty-two subjects with low back pain, 28 men and 34 women, participated in the study. Reliability was determined by using the intra class correlation coefficient and Cronbach's alpha for internal consistency. Validity was examined by correlating the JOABPEQ scores with the 36 item short form health survey (SF 36). [Results] Test-retest reliability was 0.75-0.83. The criterion-related validity was established by comparison with the Korean version of the SF 36. [Conclusion] The Korean version of the JOABPEQ was shown to be a reliable and valid instrument for assessing low back pain.

[Purpose] The purpose of this study was to establish the reliability and validity of Upper Limb Functional Index (ULFI), which has been translated into Korean, in treating patients with upper limb complaints. [Subjects and Methods] Fourty-nine subjects with upper limb disorder, 20 males and 29 females, participated in this study. Reliability was determined by using the intra class correlation coefficient and Cronbach's alpha for internal consistency. Validity was examined by correlating ULFI scores with Disability of Arm, Shoulder and Hand (DASH). [Results] Test-retest reliability was 0.90. The criterion-related validity was established by a comparison with the Korean version of DASH. [Conclusion] The Korean version of ULFI was shown to be a reliable and valid instrument for assessing upper limb complaints.

[Purpose] This study was conducted to identify the effects of expiratory muscle strength training on swallowing function in acute stroke patients with dysphagia. [Subjects and Methods] A total of 18 stroke patients with dysphagia were enrolled in the study. All participants were randomly assigned to either an experimental group (n=9) or a control group (n=9). All participants performed traditional-swallowing rehabilitation therapy in 30-minute sessions five times a week for four weeks; however, only the experimental group received expiratory muscle strength training. [Results] Both groups showed significant improvements after mediation. When compared with the control group, the functional dysphagia scale, vallecular residue, and penetration-aspiration scale were significantly improved in the experimental group. [Conclusion] Expiratory muscle strength training is an effective intervention for impaired swallowing function in acute strike patients with dysphagia.

[Purpose] The purpose of this study was to analyze the effect of Graston Technique on hamstring extensibility and pain intensity in patients with nonspecific low back pain. [Subjects and Methods] Twenty-four patients with nonspecific low back pain (27-46 years of age) enrolled in the study. All participants were randomly assigned to one of two groups: Graston technique group (n=12) and a static stretching group (n=12). The Graston Technique was used on the hamstring muscles of the experimental group, while the static stretching group performed static stretching. Hamstring extensibility was recorded using the sit and reach test, and a visual analog scale was used to measure pain intensity. [Results] Both groups showed a significant improvement after intervention. In comparison to the static stretching group, the Graston technique group had significantly more improvement in hamstring extensibility. [Conclusion] The Graston Technique is a simple and effective intervention in nonspecific low back pain patients to improve hamstring extensibility and lower pain intensity, and it would be beneficial in clinical practice.

[Purpose] The purpose of this study was to establish the reliability and validity of the Foot Function Index translated into Korean for use in patients with plantar fasciitis and foot/ankle fracture. [Subjects and Methods] Thirty-six subjects with foot complaints, 14 males and 22 females, participated in the study. Reliability was determined by using the intra-class correlation coefficient and Cronbach's alpha for internal consistency. Validity was examined by correlating Foot Function Index scores with the Short Form-36 and the Visual Analog Scale scores. [Results] Test-retest reliability was 0.90 for the pain subscale, and 0.94 and 0.91 for the disability and activity limitation subscales, respectively. The criterion-related validity was established by comparison with the Korean version of the Short Form-36 and Visual Analog Scale. [Conclusion] The Korean version of the Foot Function Index was shown to be a reliable and valid instrument for assessing foot complaints.

[Purpose] The purpose of this study was to establish the reliability and validity of the Short Musculoskeletal Function Assessment questionnaire, which was translated into Korean, for patients with musculoskeletal disorder. [Subjects and Methods] Fifty-five subjects (26 males and 29 females) with musculoskeletal diseases participated in the study. The Short Musculoskeletal Function Assessment questionnaire focuses on a limited range of physical functions and includes a dysfunction index and a bother index. Reliability was determined using the intraclass correlation coefficient, and validity was examined by correlating short musculoskeletal function assessment scores with the 36-item Short-Form Health Survey (SF-36) score. [Results] The reliability was 0.97 for the dysfunction index and 0.94 for the bother index. Validity was established by comparison with Korean version of the SF-36. [Conclusion] This study demonstrated that the Korean version of the Short Musculoskeletal Function Assessment questionnaire is a reliable and valid instrument for the assessment of musculoskeletal disorders.

[Purpose] This study compared the effects of pilates and an exercise program on the craniovertebral angle, cervical range of motion, pain, and muscle fatigue in subjects with a forward head posture (FHP). [Subjects and Methods] A total of 28 sedentary females (age 20 to 39 years) with FHP were randomly assigned to pilates (n=14) and combined (n=14) exercise groups. The study was a randomized, controlled, double-blind study with the two groups performing exercise 50 min/day, 3 days/week, with an intensity of 11-15 rating of perceived exertion (RPE) for ten weeks. The main outcome measures were craniovertebral angle, cervical range of motion (ROM), pain levels assessed by visual analog scale (VAS), and neck disability index (NDI). Surface electromyography was also used to measure muscle fatigue. [Results] There were significant increases in craniovertebral angle and cervical ROM in the pilates group, but none in the control group. The only significant differences in muscle activity were recorded in the sternocleidomastoid muscle in the pilates group. Both exercise programs had positive effects on pain measures, as VAS and NDI were significantly decreased. [Conclusion] The results suggest that pilates could be recommended as an appropriate exercise for treatment of FHP in sedentary individuals.

[Purpose] This study investigated the effects of neurofeedback (NFB) and computer-assisted cognitive rehabilitation (CACR) on the relative brain wave ratios and activities of daily living (ADL) of stroke patients. [Subjects and Methods] Forty-four participants were randomly allocated to the NFB (n=14), CACR (n=14), or control (CON) (n=16) groups. Two expert therapists provided the NFB, CACR, and CON groups with traditional rehabilitation therapy in 30-minute sessions, 5 times a week, for 6 weeks. NFB training was provided only to the NFB group and CACR training was provided only to the CACR group. The CON group received traditional rehabilitation therapy only. Before and after 6 weeks of intervention, brain wave and ADL evaluations were performed, and the results were analyzed. [Results] The relative ratio of beta waves, only showed a significant increase in the frontal and parietal areas of the NFB group. Significant changes in ADL were shown by all three groups after the intervention. However, there were no significant differences between the NFB and CACR groups and the CON group. [Conclusion] Our results suggest that CACR and NFB are effective at improving cognitive function and ADL of stroke patients.

[Purpose] This study aimed to determine the effects of different intensities of inspiratory muscle training on the relative respiratory muscle activity in healthy adults. [Subjects and Methods] Thirteen healthy male volunteers were instructed to perform inspiratory muscle training (0%, 40%, 60%, and 80% maximal inspiratory pressure) on the basis of their individual intensities. The inspiratory muscle training was performed in random order of intensities. Surface electromyography data were collected from the right-side diaphragm, external intercostal, and sternocleidomastoid, and pulmonary functions (forced expiratory volume in 1 s, forced vital capacity, and their ratio; peak expiratory flow; and maximal inspiratory pressure) were measured. [Results] Comparison of the relative activity of the diaphragm showed significant differences between the 60% and 80% maximal inspiratory pressure intensities and baseline during inspiratory muscle training. Furthermore, significant differences were found in sternocleidomastoid relative activity between the 60% and 80% maximal inspiratory pressure intensities and baseline during inspiratory muscle training. [Conclusion] During inspiratory muscle training in the clinic, the patients were assisted (verbally or through feedback) by therapists to avoid overactivation of their accessory muscles (sternocleidomastoid). This study recommends that inspiratory muscle training be performed at an accurate and appropriate intensity through the practice of proper deep breathing.

[Purpose] This study aimed to examine the effects of a visual feedback obtained from a mirror on balance ability during quiet standing in patients with stroke. [Subjects] Fifteen patients with stroke (9 males, 6 females) enrolled in the study. [Methods] Experimental trials (duration, 20s) included three visual conditions (eyes closed, eyes open, and mirror feedback) and two support surface conditions (stable, and unstable). Center of pressure (COP) displacements in the mediolateral and anteroposterior directions were recorded using a force platform. [Results] No effect of condition was observed along all directions on the stable surface. An effect of condition was observed on the unstable surface, with a smaller mediolateral COP distance in the mirror feedback as compared to the other two conditions. Similar results were observed for the COP speed. [Conclusion] Visual feedback from a mirror is beneficial for improving balance ability during quiet standing on an unstable surface in patients with stroke.

[Purpose] This study investigated the effects of progressive load and fixed load high-intensity inspiratory muscle training on the asymmetry of diaphragm thickness in stroke patients. [Subjects] Twenty-one stroke patients were assigned to one of three groups: progressive load high-intensity inspiratory muscle training (n = 8), fixed load high-intensity inspiratory muscle training (n = 6), and controls (n = 7). [Methods] The progressive load and fixed load high-intensity inspiratory muscle training participants undertook an exercise program for 20 minutes, three times weekly, for 6 weeks. After each session, diaphragm thickness was measured using ultrasonography. The diaphragm asymmetry ratio and diaphragm thickening ratio were standardized using a formula. [Results] After intervention, the diaphragm asymmetry ratio significantly differed among the three groups, and the diaphragm asymmetry ratio significantly increased in the control group. A significant increase was identified in the diaphragm thickening ratio within the progressive load and fixed load high-intensity inspiratory muscle training groups. [Conclusion] Progressive load and fixed load high-intensity inspiratory muscle training decreased the asymmetry of diaphragm thickness in stroke patients; this effect, in turn, increased the diaphragm thickening ratio in stroke patients. The two interventions examined here should be selectively applied to individuals in the clinical field.

[Purpose] The aim of this study was to determine the effects of thoracic region self-mobilization on chest expansion and pulmonary function in healthy adults. [Subjects] Nineteen healthy adults were randomly allocated to either an intervention group (n = 8) or a control group (n = 11). [Methods] Subjects in the intervention group performed self-mobilization of the thoracic region 3 times per week for 6 weeks (18 sessions). The outcome measures included chest expansion when breathing, pulmonary function, and predicted pulmonary function. [Results] There was a significant difference in chest expansion between the intervention group and the control group. However, there was no significant difference in pulmonary function between the intervention group and the control group. [Conclusion] Thoracic region self-mobilization may be beneficial for increasing chest expansion in healthy adults.

[Purpose] The aim of this study was to examine whether plantar flexor static stretching and dynamic stretching using an Aero-Step results in changes in foot pressure during gait in healthy adults. [Subjects] Eighteen normal adults were randomly allocated to either a dynamic stretching using an Aero-Step group (DSUAS) group (n = 8) or a static stretching (SS) group (n = 10). [Methods] The DSUAS and SS participants took part in an exercise program for 15 minutes. Outcome measures were foot plantar pressure, which was measured during the subject's gait stance phase; the asymmetric ratio of foot pressure for both feet; and the visual analogue scale (VAS) measured during the interventions. [Results] There were significant differences in the asymmetric ratio of foot pressure for both feet and VAS between the two groups after intervention. However, there were no significant differences in foot plantar pressure during the gait stance phase within both groups. [Conclusion] DSUSAS is an effective stretching method, as pain during it is lower than that with SS, which can minimize the asymmetric ratio of foot pressure for both feet during gait due to asymmetric postural alignment.

[Purpose] The aim of the present study was to investigate the current evidence for the effect of exercise on glycemic control, the lipid profile, body composition, vascular health, and complications in Korean patients with type 2 diabetes. [Subjects and Methods] The subjects were 1,263 patients receiving outpatient care at 13 general hospitals located in Seoul and Gyeonggido who were subjected to examinations in the areas of blood glucose management, complications management, and diabetes education between March 19 and May 29, 2013. The relations between exercise and various regulatory factors including patient's general and clinical characteristics, metabolic regulation, achievement of goals for metabolic regulation, and complication incidence in patients with type 2 diabetes were investigated. [Results] Exercise management was associated with a decrease in systolic blood pressure, fasting glucose, postprandial glucose, hemoglobin A1c, total cholesterol, triglyceride, and low-density lipoprotein Regarding achievement of goals for metabolic regulation, significant odds ratios were observed for the effect of exercise treatment on blood pressure, fasting glucose, postprandial glucose, hemoglobin A1c, triglyceride, HDL in men, and BMI in patients with type 2 diabetes. Moreover, exercise management was associated with decreased occurrence of cerebrovasculopathy. [Conclusion] In conclusion, exercise induced metabolic regulation of glycemic control, the lipid profile, and body composition, as well as vascular health and complications, in Korean patients with type 2 diabetes.

[Purpose] This study investigated brain wave, memory and attention changes in adult stroke patients using computer assisted cognitive rehabilitation (CACR). [Subjects] Twenty-five stroke patients were randomly allocated to either the CACR group (n=12) or the control group (n=13). [Methods] Two expert therapists provided the CACR group and the control group with traditional rehabilitation therapy in 30-minute sessions, semi-weekly, for 6 weeks. CACR was provided only to the CACR group. The control group received traditional rehabilitation therapy only. Before and after the 6 weeks of intervention, electroencephalography (EEG) and a computerized neurocognitive function test (CNT) were performed, and the results were analyzed. [Results] After the intervention, the CACR group showed significant differences in the frontal lobe (Fp1, Fp2, and F4) and in the parietal lobe (P3 and P4), and also showed significant differences in CNT memory (DST and VST forward/backward test) and attention (VCPT correct responses), but no notable changes were observed in the control group. [Conclusion] These results suggest that CACR is feasible and suitable for individuals with stroke. Detailed and diverse investigations should be performed considering the numbers and characteristics of subjects, and the limitations affecting the CACR training period.

[Purpose] This study analyzed the activities of the back and hip muscles during Pilates exercises conducted in a prone position. [Subjects] The subjects were 18 healthy women volunteers who had practiced at a Pilates center for more than three months. [Methods] The subjects performed three Pilates exercises. To examine muscle activity during the exercises, 8-channel surface electromyography (Noraxon USA, Inc., Scottsdale, AZ) was used. The surface electrodes were attached to the bilateral latissimus dorsi muscle, multifidus muscle, gluteus maximus, and semitendinous muscle. Three Pilates back exercises were compared: (1) double leg kick (DLK), (2) swimming (SW), and (3) leg beat (LB). Electrical muscle activation was normalized to maximal voluntary isometric contraction. Repeated measures analysis of variance was performed to assess the differences in activation levels among the exercises. [Results] The activity of the multifidus muscle was significantly high for the SW (52.3±11.0, 50.9±9.8) and LB exercises(51.8±12.8, 48.3±13.9) and the activity of the semitendinosus muscle was higher for the LB exercise (49.2±8.7, 52.9±9.3) than for the DLK and SW exercises. [Conclusion] These results may provide basic material for when Pilates exercises are performed in a prone position and may be useful information on clinical Pilates for rehabilitation programs.

[Purpose] The purpose of the present study was to verify a new method for improving respiratory functions by applying both abdominal stimulation and inspiratory muscle training (IMT) to train the inspiratory muscle and the expiratory muscle simultaneously, to improve the efficiency of IMT of chronic stroke patients. [Subjects] Eighteen stroke patients were randomly assigned to an experimental group (n = 9) and a control group (n = 9). [Methods] The experimental group was administered IMT with abdominal stimulation, and the control group was administered only IMT. During the intervention period, the experimental group and control group received training 20 min/day, 3 times/wk, for 4 weeks. To examine the lung functions of the subjects, FVC, FEV1, PEF, and FEF25-75 were measured using an electronic spirometer. The diaphragm thickness ratio was calculated from measurements made with a 7.5-MHz linear probe ultrasonic imaging system. [Result] The experimental group and the control group showed significant increases in diaphragm thickness ratio on the paretic side, but not on the non-paretic side. With regard to lung function, the experimental group showed significant increases in FEV1, PEF, and FEF25-75. The changes between before and after the intervention in the two groups were compared with each other, and the results showed significant differences in FEV1 and PEF. [Conclusion] The present study identified that IMT accompanied by abdominal stimulation improved the pulmonary function of chronic stroke patients.

[Purpose] The aim of this study was to assess the effect of Nordic pole walking on the electromyographic activities of upper extremity and lower extremity muscles. [Subjects and Methods] The subjects were randomly divided into two groups as follows: without Nordic pole walking group (n=13) and with Nordic pole walking group (n=13). The EMG data were collected by measurement while the subjects walking on a treadmill for 30 minutes by measuring from one heel strike to the next. [Results] Both the average values and maximum values of the muscle activity of the upper extremity increased in both the group that used Nordic poles and the group that did not use Nordic poles, and the values showed statistically significant differences. There was an increase in the average value for muscle activity of the latissimus dorsi, but the difference was not statistically significant, although there was a statistically significant increase in its maximum value. The average and maximum values for muscle activity of the lower extremity did not show large differences in either group, and the values did not show any statistically significant differences. [Conclusion] The use of Nordic poles by increased muscle activity of the upper extremity compared with regular walking but did not affect the lower extremity.

[Purpose] The purpose of this study was to examine the effects of smoking on teenagers' internal oblique (IO) and transverses abdominis (TrA) expiratory muscles and their pulmonary function. [Subjects] A total of 30 healthy teenagers (15 smokers; 15 nonsmokers) voluntarily participated in the study. [Methods] The subjects were instructed to maintain an upright standing posture with their scapulars against the wall. Measurements were then taken to determine the thickness of their right IO and their right TrA while they were at rest and in a state of forced expiration using a 7.5 MHz linear probe of an ultrasonic imaging system. The measured thickness was converted into the percentage of change in muscle thickness (PCMT) and the relative contribution ratio (RCR) using a calculation formula, and then the data were analyzed. [Results] No significant differences were found between the two groups in the thickness, PCMT, and RCR of both the IO and TrA muscles, while there were significant differences in the forced expiratory volume at one second (FEV1) and the peak expiratory flow (PEF). [Conclusion] This study examined teenage smokers whose duration of smoking was relatively short. The two groups did not show significant differences in the thickness of both the IO and TrA muscles. However, based on the forced expiratory volume at one second (FEV1) and PEF measurements, the smokers showed greater decreases in pulmonary function than the nonsmokers.