• PNF and Movement
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• v.20 no.2
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• pp.285-293
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• 2022

Purpose: The purpose of this study was to confirm that the activation of the contralateral muscles changes according to posture after applying the proprioceptive neuromuscular facilitation leg pattern. Methods: Ten healthy adults (four males and six females) with no history of current musculoskeletal/neurological injuries were recruited for this study. Abdominal muscle (transverse abdominis) and hip joint muscle (gluteus maximus and gluteus medius) activation was assessed using surface electromyography (Ultium EMG, Noraxon Inc., USA). We evaluated muscle activation during the application of the PNF leg pattern. The data were analyzed using the SPSS version 21.0 program. Results: The results were found to be statistically significantly different in the 90/90 supine posture and sitting posture for the gluteus maximus (p < 0.05). The results were found to be not statistically significantly different for the transverse abdominis according to posture (p > 0.05). The results were found to be not statistically significantly different for the gluteus medius according to posture (p > 0.05). Conclusion: Application of the PNF leg pattern resulted in a significant change in the muscle activation of the contralateral segment according to posture, and the 90/90 supine posture induced high muscle activation of the gluteus maximus. In addition, the activation of the transverse abdominis was high in all three postures.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.129-136
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• 2018

PURPOSE: This Study compared the level of activation of the muscles around the shoulder at the time of abduction through Pilates breathing and regular breathing by using quantified biofeedback. METHODS: Experiment was conducted on 25 healthy males and females in the age bracket of 20's~30's as the subjects. The level of activation of muscles displayed at the time of Pilates breathing were measured at intercostal (InC) muscle, transverse abdominis (TrA) muscle, internal oblique (IO) muscle and external oblique (EO) muscle by using surface electromyogram (EMG) and were provided as biofeedback. Moreover, the changes in the level of muscular activation at sternocleidomastoid (SCM) muscle, upper trapezius (UT) muscle and Deltoid (Del) muscle, which are the muscles around the shoulder, at the time of abduction of shoulder during Pilates breathing and regular breathing were measured. RESULTS: When abduction of shoulder is executed through Pilates breathing, the level of muscular activation of UT muscle was $11.56{\pm}7.10%$ at the time of exhaling of Pilates breathing and $17.54{\pm}9.57%$ at the time of exhaling of regular breathing. Del muscle also displayed lowered level of muscular activation at the time of Pilates breathing with $12.88{\pm}5.80%$ during inhaling and $15.14{\pm}5.49%$ during exhaling. CONCLUSION: In conclusion, the results could be interpreted as indicating that the muscle activities of upper trapezius and deltoid muscle were decreased based on Pilates breathing more than those on regular breathing.

• PNF and Movement
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• v.17 no.1
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• pp.111-118
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• 2019

Purpose: This study aimed to investigate the correlation between trunk stabilization muscle activation and the parameters of gait analysis in healthy individuals. Methods: Thirty healthy adults (15 male, 15 female) with no history of lower back pain (LBP) or current musculoskeletal and neurological injuries were studied. Trunk stabilization muscle activation (e.g., external oblique, internal oblique, transverse abdominis, erector spinae) were assessed using surface electromyography. To analyze gait, we measured temporal parameters (e.g., gait velocity, single support phase, double support phase, swing phase, and stance phase) and a spatial parameter (e.g., H-H base of support). Results: A statistically significant correlation was found between the internal oblique, transverse abdominis, and erector spinae muscle activity and gait velocity, single support phase, double support phase, swing phase, and stance phase. No statistically significant correlation was found between the external oblique muscle activity and the gait velocity, single support phase, double support phase, swing phase, and stance phase. No statistically significant correlation was found between the external oblique, internal oblique, transverse abdominis, and erector spinae muscle activity and the spatial parameter. Conclusion: This study demonstrated that a relationship exists between trunk stabilization muscle activation and temporal parameter (i.e., gait velocity, single support phase, double support phase, swing phase, and stance phase) during gait analysis. Therefore, the trunk's stabilizer muscles play an important role in the gait of healthy individuals.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.2
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• pp.165-171
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• 2012

Purpose : The purpose of this study was to investigate the change of abdominal muscle activation during unilateral leg raising in supine position among three hip abduction angles($0^{\circ}$, $15^{\circ}$, $30^{\circ}$). Methods : Twenty eight able-body volunteers who had no medical history of low back and hip joint were recruited for this study. Abdominal muscle activity was recorded using surface EMG from both sides of the rectus abdominis, internal/external oblique muscle during leg raising in each position. Results : The muscle activations induced under the three different positions were compared and results showed that there was significant difference only in the right external oblique muscle activation. Conclusion : This study suggest that leg raising of different hip abduction angles without trunk control has little influence on abdominal muscle co-activation.

• Physical Therapy Korea
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• v.20 no.1
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• pp.28-35
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• 2013

The purpose of this study was to determine the effects of warm-up and cool-down exercises on pain and muscle activation of delayed onset muscle soreness after intense exercise. Delayed onset muscle soreness was caused by the eccentric exercise in the elbow flexor muscle of the non-dominant upper limb. Forty-four subjects volunteered to participate in this study and were randomly assigned to one of the following groups: warm-up and cool-down group, only warm-up group, only cool-down group, or control group with no intervention. The level of perceived pain using the visual analogue scale and electromyographic activation change in maximal voluntary isometric contraction were measured 4 times at the following times: 10 min, 24 hr, 48 hr, and 72 hr after the exercise. The results revealed the main effect between the groups and interaction effect between the group and measurement session (p<.05). The warm-up and cool-down group showed most favorable results with respect to reduced perceived pain level and increased muscle strength in most measurement sessions, and the only warm-up group showed significantly more decreased pain level than the control group at 24 hr and 48 hr and more increased muscle activation than the cool-down group at 48 hr (p<.05). However, there were no significant differences in pain level and muscle activation between the only cool-down group and control group at all measurement sessions (p>.05). The findings suggest that the warm-up exercise performed before an intense exercise had beneficial effects on the symptoms of delayed onset muscle soreness, whereas cool-down exercise performed after the intense exercise did not.

• PNF and Movement
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• v.16 no.1
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• pp.125-132
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• 2018

Purpose: The aim of this study was to investigate the isolated activation ratio of the quadriceps femoris muscle on different support surfaces during squat exercise. Methods: Twenty participants (10 males and 10 females) voluntarily agreed to participate in the research after receiving an explanation about the purpose and process of the study. Each participant performed squat exercises on three different support surfaces (a flat surface, a form roller, and an unstable surface). Muscle activities of the rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) were measured by electromyography. The isolated activation ratio of the quadriceps femoris muscle was calculated using the %isolation formula. Results: For the squat exercise, the %isolation value of the VM was significantly higher on the unstable surface than on the flat surface and form roller. In contrast, the %isolation values for the RF for the squat exercise were significantly higher on the flat surface and form roller than on the unstable surface. There was no significant differences in the %isolation values of the VL on the three different surfaces. Conclusion: The findings indicate that squat exercise on different surfaces results in differential activation of the quadriceps femoris muscle, which suggests that squat exercise on a multi-directional unstable surface could increase the isolated activation ratio of the VM.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.70-70
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• 1993

Fundamental frequency is controlled by contraction of both TA and CT muscle. While activity of the CT is known well, little is known regarding the effect of the TA muscle on vocal fold vibration. To study this, a previously developed in vivo canine laryngeal model was modified. Isolated TA muscle activation was obtained by stimulating sectioned terminal TA branches through small thyroid cartilage windows. The results indicated that TA muscle activation is a major determinant in vocal register shift from falsetto to modal phonation. F0 increased with increasing TA activation in modal register, On the other hand, the F0 decreased with TA activation when the evoked voice belonged to falsetto register. Subglottic pressure increased gradually and OQ decreased gradually with TA activation.

• Physical Therapy Rehabilitation Science
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• v.5 no.3
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• pp.120-124
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• 2016

Objective: Chronic lateral epicondylitis is a condition which becomes sore and tender on the lateral side of the elbow joint damaged from overuse and repetitive use of the extensor muscles of the forearm. The purpose of this study was to investigate the effects of flexion degrees in the elbow joint on extensor carpi radialis longus and brevis and biceps brachii muscles in individuals with healthy young adults. The main purpose of this study was to suggest the feasibility of optimal elbow angle during therapeutic eccentric exercise with resistance for strengthening of wrist extensors. Design: Cross-sectional study. Methods: Thirty health young adults (male 15, female 15) participated in this study. This study measured muscle activation in four different conditions of elbow flexion, $0^{\circ}$, $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$ during eccentric exercise with weight loading in wrist extensors, extensor carpi radialis longus and brevis and biceps brachii muscles using surface electromyography. Results: The muscle activation of extensor carpi radialis showed a negative relationship with the degrees of elbow joint flexion. With increasing elbow flexion angles, the ECRL muscle activation amount was significantly lower (p<0.05). In contrast, the muscle activation of the ECRB muscle activation amount was significanlty higher (p<0.05). Conclusions: This study suggests that the eccentric exercise of wrist extension with selected activation of wrist extensor muscles according to elbow flexion positions, and suggests that the extensor carpi radialis longus and brevis will need to be strengthened for preventing and treating chronic lateral epicondylitis regardless of degrees of elbow joint flexion.

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.535-547
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• 2000

Recent findings indicate that mechanical strain (deformation) exerted by the extracellular matrix modulates activation of airway smooth muscle cells. Furthermore, cytoskeletal organization in airway smooth muscle appears to be dynamic, and subject to modulation by receptor activation and mechanical strain. Mechanosensitive modulation of crossbridge activation and cytoskeletal organization may represent intracellular feedback mechanisms that limit the shortening of airway smooth muscle during bronchoconstriction. Recent findings suggest that receptor-mediated signal transduction is the primary target of mechanosensitive modulation. Mechanical strain appears to regulate the number of functional G-proteins and/or phospholipase C enzymes in the cell membrane possibly by membrane trafficking and/or protein translocation. Dense plaques, membrane structures analogous to focal adhesions, appear to be the primary target of cytoskeletal regulation. Mechanical strain and receptor-binding appear to regulate the assembly and phosphorylation of dense plaque proteins in airway smooth muscle cells. Understanding these mechanisms may reveal new pharmacological targets for control1ing airway resistance in airway diseases.

• The Journal of Korean Physical Therapy
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• v.28 no.3
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• pp.189-194
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• 2016

Purpose: This study focuses on influence of ankle stabilization training on balance ability and lower limb muscle activation of soccer player with functional ankle instability. Methods: Subjects were grouped into ankle stabilization training group using biofeedback comprised of 15 subjects and general exercise group of 15. The training was conducted for 30 minutes, 3 times a week for 8 weeks in total. All 30 football players conducted plyometric training for 30 minutes before main training. To evaluate balance ability, biorescure was used to measure whole path length and surface area and surface electromyography (EMG) system was used to measure tibialis anterior, tibialis posterior, and soleus to evaluate lower limb muscle activation. Results: The experiment group showed significant difference to the comparison group in regard of whole path length and surface area which represents balancing capability and muscle activation of tibialis anterior, tibialis posterior, and soleus. Conclusion: Therefore, ankle stabilization training using biofeedback is more effective in enhancing balance ability and lower limb muscle activation than general exercise.