• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.1
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• pp.25-31
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• 2023

Background: In this study, the abductor hallucis activity and medial longitudinal arch angle were compared by performing four exercises, namely the short foot exercise, the short foot exercise with 2^nd~5^th toe extension, the short foot exercise with 2^nd~5^th toe extension with a load of 1kt on the sole, and the short foot exercise with 2^nd~5^th toe extension with a load of 2kg on the sole. Methods: Four short foot exercises as described above were performed by 20 healthy adult males and females. The abductor hallucis activity and medial longitudinal arch angle were measured and analyzed by surface electromyography and the Kinovea software program. Results: The short foot exercise with 2^nd~5^th toe extension, short foot exercise with 2^nd~5^th toe extension with a load of 1kg on the sole, and the short foot exercise with 2^nd~5^th toe extension with a load of 2kg on the sole showed significantly higher abductor hallucis activity than the short foot exercise alone. Among these, the short foot exercise with the 2^nd~5^th toe extension was the most effective. All exercises showed a significantly decreased medial longitudinal arch angle post-exercise than pre-exercise, and the short foot exercise with the 2^nd~5^th toe extension showed a significantly decreased medial longitudinal arch angle compared to the other three exercises. Conclusion: It is believed that the short foot exercise with the 2^nd~5^th toe extension can be proposed as an effective exercise that can replace the short foot exercise alone.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.1
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• pp.69-79
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• 2023

Purpose: This study examined the possibility of muscle strength and balance ability improvement through coordinative locomotor training by making a difference on the supporting plane using a resistance band for adolescent athlete of Taekwondo sparring athletes. Methods: A total of 22 students were selected as to the participants of the study, and 11 students each were randomly assigned to the control and experimental group for coordination locomotor training using a resistance band on stable and unstable supporting surface. The training period was 60 min, three times a week, for 8 weeks in total. To confirm changes on balance ability of each participant, balance assessment devices are used. Moreover, surface electromyography was used for muscle strength evaluation. Results: After coordinated locomotor training using a resistance band for 8 weeks, the difference bet ween groups was not significant; Also, the improvement in strength was no significant difference in other muscles in the between groups, but there was a significant in the muscle activity of the rectus muscle of the right thigh in the experimental group. Conclusion: The participants demonstrated that coordinative locomotor training using the elastic band on an unstable supporting surface was able to obtain junctional effects for the prevention of exercise injuries in youth taekwondo sparring athletes, and muscle activity exercise of the rectus muscle of the right thigh was particularly effective.

• Physical Therapy Korea
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• v.30 no.1
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• pp.23-31
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• 2023

Background: Several factors contribute to shoulder pain, including abnormal neck posture, repeated use of the upper limbs, work involving raising the upper limbs above the head, and the effects of vibration. However, previous study has reported that constant vibration exposure could impact improvement of the stability on joints related with muscle recruitment and activation. For this difference reason, we need to verify for the complex study of relationship with repetitive upper limb movements, poor head posture, and constant vibration exposure. Objects: Our study was made to investigate the influence of vibration exposure on the shoulder muscle activity during forward-head and over-head tasks with isometric shoulder flexion. Methods: In a total of 22 healthy subjects, surface electromyography (EMG) data were collected from shoulder muscles (upper/lower trapezius, serratus anterior, and lumbar erector spinae) on tasks (neutral-head task [NHT], forward-head task [FHT], and over-head task [OHT]) with and without vibration exposure. Results: In all tasks, the EMG data of the upper trapezius and serratus anterior significantly increased with vibration exposure (p < 0.05). Furthermore, the EMG data of the lumbar erector spinae significantly increased with vibration exposure in the NHT and FHT (p < 0.05). Conclusion: We suggest that continuous vibration exposure during the use of hand-held tools in the tasks could be associated with harmful effects in the workplace. Lastly, we clinically need to examine the guidelines regarding the optimal posture and vibration exposure.

• Physical Therapy Rehabilitation Science
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• v.12 no.1
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• pp.26-32
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• 2023

Objective: This study attempted to compare the effects of bridge exercise using a sling according to the angle of the ankle to confirm the effective lower extremity muscle activation posture of patients with patellofemoral pain syndrome(PFPS). Design: Cross-sectional study Methods: Seventeen patients with PFPS were recruited and the muscle activities of the vastus medialis, vastus lateralis, rectus femoris, and gluteus maximus were measured according to the ankle position (dorsiflexion, neutral, plantar flexion). After measuring the maximum number of isometric contractions of vastus medialis, vastus lateralis, rectus femoris, and gluteus maximus, bridging exercise using a sling according to each ankle posture was applied to measure lower extremity muscle activity. The evaluation was performed 3 times for 10 seconds. The three ankle postures were randomly performed and the average values were compared. Results: As a result of this study, the vastus medialis muscle showed high muscle activity in the order of dorsiflexion, plantar flexion, and neutral position bridge exercise (p<0.05). And the vastus lateralis showed high muscle activity in the order of dorsiflexion, neutral, and plantar flexion (p<0.05). However, rectus femoris and gluteus maximus did not show significant muscle activity according to the ankle posture, but muscle activity was highest in the dorsiflexion posture. Conclusions: As a result of this study, muscle activity was high in the order of vastus medialis and vastus lateralis during ankle dorsiflexion. This is thought to be a major factor that can be applied in various ways in clinical practice according to the ankle angle when treating PFPS patients.

• PNF and Movement
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• v.21 no.1
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• pp.139-146
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• 2023

Purpose: The aim of this study is to provide basic information to create an efficient training program to improve shoulder stability and function in patients with injuries and in patients having undergone surgery of the supraspinatus and infraspinatus muscles, which have a relatively high incidence of injury in shoulder joint disease. Further, independent activities of the supraspinatus and infraspinatus muscles were investigated according to forearm rotation and the neutral and lateral rotation postures. Methods: The activities of the supraspinatus and infraspinatus muscles were measured using surface electromyography in 22 healthy adults in Busan, and isokinetic muscle strength measurement equipment was used to measure muscle strength during shoulder lateral rotation. The subjects performed lateral rotation of the shoulder in three different forearm postures (neutral, supine, prone) to measure shoulder muscle activity and lateral rotation strength. Results: The independent activity ratio (% Isolation) of the supraspinatus and infraspinatus muscles during lateral rotation of the shoulder joint demonstrated a significant difference (p<0.05) according to the change in forearm posture. Conclusion: The supraspinatus muscle showed independent activity ranging from highest to lowest in the order of pronation, neutral, and supination of the forearm, while the independent activity of the infraspinatus muscle ranged from highest to lowest in the order of neutral, supination, and pronation of the forearm. Therefore, the most active forearm positions for the supraspinatus and infraspinatus muscles are pronation and neutral, respectively.

• Journal of Sport and Applied Science
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• v.7 no.2
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• pp.1-12
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• 2023

Purpose: The purpose of this study was to investigate the possibility of modified swing to prevent shoulder injury by analyzing differences in the muscle activation patterns of upper limb by the swing method in wheelchair badminton players. Research design, data, and methodology: 10 wheelchair badminton players participated in the experiment as subjects and performed 10 high clears and 10 smashes in both traditional and modified swing methods toward a shuttlecock hung at the height of racket impact point. For each trial, activation patterns of biceps brachii, triceps brachii, anterior deltoid, and posterior deltoid were measured from the upper limb participating in the swing from which the duration, peak, and root mean square (RMS) of electromyography (EMG) activities from swing initiation to shuttle impact were calculated. The maximum swing velocity of the smash and the distance of the high clear were also measured with both methods to compare differences in the swing velocity and shuttle hit distance. Results: Differences in the EMG peak and RMS of the anterior deltoid by swing methods were shown to differ by the skill type, being higher in the traditional swing method than the modified during only the high clear. The EMG peak and RMS, and the duration of the posterior deltoid were higher and longer with the traditional swing method than the modified during both the smash and high clear. The intensities of the biceps brachii and triceps brachii activities measured during the smash and high clear were higher in the traditional swing method than the modified, and the biceps brachii and triceps activity durations during the high clear were shorter in the modified swing method than the traditional. The maximum swing velocity of the smash was faster with the traditional swing method than the modified, while the distance of the high clear did not differ significantly. Conclusions: These results suggest that the modified swing can be an effective performance method for preventing shoulder injuries without undue loss of impact power in wheelchair badminton players by reducing excessive loads imposed on the shoulder and allowing the optimal use of the elbow extension.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.400-408
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• 2022

Objective: The purpose of this study is to compare EMG activity during horticulture motion and upper limb rehabilitation motion, to confirm whether horticulture motion is suitable for upper extremity rehabilitation of hemiparesis. Design: Three-group cross-sectional design. Methods: The 45 subjects were divided into three groups: hemiparesis (n=15), elderly (n=15) and healthy (n=15). We have recorded EMG signals of six upper limb muscles Upper trapezius (UT), Middle deltoid (MD), Anterior deltoid (AD), Biceps brachii (BB), Triceps brachii (TB), Brachioradialis (BR) during horticultural motions and three upper limb rehabilitative motions. The dependent variables were peak EMG, integral EMG, co-contraction ratio. A two-way repeated measures ANOVA was used to compare the horticultural motion and rehabilitation motion of the three groups. Results: The peak EMG was significantly different in MD, AD, BB, TB according to the motion(p<0.05), and the UT, BB were significant differences according to the group(p<0.05). The integral EMG was significantly different in MD, AD, BB, TB, BR according to the motion(p<0.05), and the BB were significant differences according to the group(p<0.05). The co-contraction ratio was significantly different in TB/BB according of the motion, and there was no difference between the groups. Conclusions: As a result of this study, horticultural motion alone was insufficient for upper arm rehabilitation, and horticultural motion alone was insufficient to induce continuous activity of the forearm.

• Fashion & Textile Research Journal
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• v.25 no.2
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• pp.210-220
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• 2023

Recently, smart wearable products, including electromyography (EMG) measurement devices and clothing, have been developed to monitor users' exercise levels, muscle activation, and muscle balance more effectively during fitness activities. However, technical and socioeconomic barriers, such as flexibility and durability, still pose challenges in terms of comfort, ease of wear, and wearability of smart clothing, which includes devices and circuits. To address these issues, this study developed a wearable EMG device integrated with clothing to collect valid EMG signals from desired muscles while maintaining comfort, functionality, and ease of wear. After deriving a combined structure that could stably position the wearable device within the clothing, a prototype was manufactured and evaluated for fit, compression, comfort, and exercise comfort test by ten participants (height = 176.2 cm, weight = 76.4 kg, chest circumference = 101.2 cm). The study found that the prototype had smaller circumferences around the chest, waist, and abdomen compared to commercial products, resulting in lower ratings for wearing comfort and ease of wear. However, the prototype received high ratings for fitting, pressure, and the exercise comfort test. Valid signals were obtained when the EMG device was combined to the prototype for the rectus femoris muscle, indicating stable positioning of the device during exercise.

• Safety and Health at Work
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• v.13 no.4
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• pp.440-447
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• 2022

Background: Agricultural handle equipment is present on all production areas' farms. They are handy and portable; however, excessive use can lead to acute traumas or accidental injuries. Repetitive movements, awkward postures, and hand-arm vibrations predispose them to pain and work-related musculoskeletal disorders. The purpose of this study was to observe the interaction of handle equipment in terms of electromyographic activity and analyze the postural work-related alterations. Materials and methods: Twenty male agricultural operators, mean age 24±1.54 years, underwent the electromyographic analysis testing their muscular activities with a brushcutter, electric saw, and hedge trimmer in four different test conditions. Results: The brushcutter proved to be the agricultural handle equipment with the higher mean frequency (3.37±0.38 Hz) and root mean square (5.25±1.24 ms^-2). Furthermore, the digital postural analysis showed a general asymmetry of the main arm and the respective side of the trunk. The head resulted right inclined in the anterior frontal plane by 5.7°±1.2°; the right scapula lower than the left in the posterior frontal plane (8.5°±1.8°), and a working trunk inclination of 34.15°±5.7°. Conclusions: Vibrations of handle equipment and awkward working postures represent a risk for agricultural operators. Preventive measures are required to avoid young operators from experiencing musculoskeletal disorders all lifelong.

• Physical Therapy Korea
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• v.30 no.2
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• pp.160-168
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• 2023

Background: Individuals with scapular winging have a weak serratus anterior (SA) muscle, and to compensate, the pectoralis major (PM) and upper trapezius (UT) muscles excessively activate, which can cause upper extremity dysfunction. This study aimed to compare the effects of isometric horizontal abduction (IHA) on SA, PM, and UT muscle activity, as well as the SA/PM and SA/UT muscle activity ratios during knee push-up plus (KPP) at 90° and 120° of shoulder flexion. Objects: This study aimed to compare the effects of IHA on SA, PM, and UT muscle activity, as well as the SA/PM and SA/UT muscle activity ratios during KPP at 90° and 120° of shoulder flexion. Methods: This study, conducted at a university research laboratory, included 20 individuals with scapular winging. Participants performed KPP with and without IHA at 90° (KPP90) and 120° (KPP120) of shoulder flexion. SA, PM, and UT muscle activity were measured using surface electromyography. Results: PM activity in KPP90 with IHA was significantly lower than KPP90 and in KPP120 was significantly lower than KPP90. UT activity was significantly greater with IHA than without IHA and at 120° than 90° of shoulder flexion. SA/PM muscle activity ratio was significantly higher in KPP90 with IHA than without IHA and in KPP120 than in KPP90. SA/UT muscle activity ratio was significantly lower with IHA than without IHA. Conclusion: KPP90 with IHA and KPP120 are effective exercises to reduce PM activity and increase SA/PM muscle activity ratio. However, applying IHA in KPP90 also reduces SA/UT muscle activity ratio, implying that it would be preferable to apply KPP120 in individuals overusing their UT muscles.