• Physical Therapy Korea
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• v.23 no.2
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• pp.67-74
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• 2016

Background: Lumbar stabilization (LS) improve the thickness of the quadratus lumborum (QL) muscle and muscle activity of the gluteus medius (GM) muscle during hip abduction in a side-lying position in patients with low back pain (LBP). Objects: The purpose of this study was to assess the effects of LS on muscle thickness of QL and muscle activity of GM during hip abduction in side-lying in patients with LBP. Methods: The study included 32 patients with LBP, who were randomly divided into the control group and experimental group, each with 16 patients. All subjects performed $35^{\circ}$ preferred hip abduction (control group) and $35^{\circ}$ hip abduction with LS (experimental group) during side-lying. An ultrasonography and a surface electromyography were used to measure the thickness of the QL muscle, and the muscle activities of the GM muscle respectively. Independent t-test was used to compare the muscle thickness of the QL and the muscle activity of the GM muscle, respectively. Results: Anterio-posterior diameter in the muscle thickness of QL muscle was decreased significantly in hip abduction with LS more than in preferred hip abduction (p<.001), but medio-lateral diameter in the muscle thickness of QL muscle was not significantly different between in preferred hip abduction and in hip abduction with LS (p=.06). The muscle activity of GM was increased significantly in hip abduction with LS more than in preferred hip abduction (p<.001). Conclusion: These findings suggest that hip abduction with LS could be recommended as a hip abduction for LS and a prevention unwanted compensatory pelvic lateral tilting movement.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.2
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• pp.1-9
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• 2020

PURPOSE: This study examined the effects of different external loads on the muscle activities around the hip during prone hip extension with knee flexion (PHEKF) exercise in healthy young men. METHODS: Sixteen healthy adult males participated in the study. A pressure biofeedback unit was used to provide feedback to the participants during the abdominal drawing-in maneuver (ADIM) with PHEKF. Sandbags (0 kg, 1 kg, 2 kg, and 3 kg) were used to provide external resistance. The quadriceps was contracted to maintain knee flexion 90° against resistance. Each resistance condition using a sandbag weight was given in random order. Surface electromyography (sEMG) was used to measure the electrical activity of the gluteus maximus, biceps femoris, and erector spinae during PHEKF. RESULTS: The muscle activity of the gluteus maximus was highest with the 3 kg resistance and lowest with 0 kg (F = 128.46, P = .00). The muscle activities of the biceps femoris and erector spinae were highest with 0 kg and lowest with 3 kg (F = 29.49, P = .00). The muscle activity rate of the gluteus maximus/biceps femoris was highest with 3 kg and lowest with 0 kg (F = 37.49, P = .00). CONCLUSION: The activity of the gluteus maximus was increased using a higher external weight load during PHEKF, while the activity of the biceps femoris decreased. These findings suggest that an external weight is needed during hip extensor exercise to strengthen the gluteus maximus and inhibit the biceps femoris.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.25-31
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• 2007

The purpose of this study was to investigate the strength and endurance of the deep neck flexor muscles in individuals with work-related neck pain. Subjects consisted of two groups: twenty industrial workers with neck pain and twenty age-matched healthy subjects. To evaluate the strength and endurance of deep cervical flexors, maximum voluntary contractile strength (MVCS) and a sustained time at sub-maximal voluntary contractile strength (SMVCS) (80% and 50% of MVCS) were measured using a pressure biofeedback unit and a stop watch in supine. The MVCS of deep neck flexor muscles was 29.67${\pm}$4.56 in neck pain group and 54.27${\pm}$6.78㎜Hg in normal group. The sustained time at 80% SMVCS was 12.42${\pm}$2.64 seconds and 55.12${\pm}$12.76 seconds in the groups with and without neck pain. The sustained time at 50% SMVCS was 25.40±5.88 seconds and 109.70${\pm}$31.50 seconds in the groups with and without neck pain. The difference of the lower jaw position was 16.75${\pm}$3.57㎜ and 23.03${\pm}$2.51㎜. The MVCS, endurance at the two sub-maximal levels and the difference of the lower jaw position were significantly greater in the group without neck pain than with neck pain (p$<$0.05). The findings indicate that the maximal strength and endurance of the deep neck flexors were decreased in the workers with neck pain compared to those without neck pain. Therefore, it is necessary to include strengthening and endurance exercises of the deep neck flexor muscles in therapeutic program of work-related musculoskeletal disorders involving neck pain.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.4
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• pp.139-146
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• 2016

PURPOSE: The purpose of this study was to determine the effect of craniocervical flexion exercise with masticatory muscle contraction in patients with neck pain. Patients with neck pain also experience muscle weakness and limitation of activities of daily living. Craniocervical flexion exercise with masticatory muscle contraction may increase the thickness of the deep cervical flexor muscles, thereby reducing pain and limitations on activities of daily living. METHODS: Twenty-six volunteers participated in this study. The subjects were randomly divided into an experimental group (n=13) and a control group (n=13). Both groups performed craniocervical flexion exercise using a pressure biofeedback unit; the experimental group performed craniocervical flexion exercise with masticatory muscle contraction for 20 minutes, 3 times a week for 4 weeks. Assessment tools included ultrasonography for measurement of muscle thickness and the Neck Disability Index for the level of pain and function. RESULTS: The rate of change in muscle thickness in both groups significantly increased (p<.05), with a significantly greater increase in the experimental group than in the control group (p<.05). The Neck Disability Index score significantly improved (p<.05) in both groups, with significantly greater improvement in the experimental group compared with the control group (p<.05). CONCLUSION: These results suggest that craniocervical flexion exercise with masticatory muscle contraction can be effective in increasing muscle thickness and improving the Neck Disability Index score in patients with neck pain.

• Physical Therapy Korea
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• v.18 no.4
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• pp.1-10
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• 2011

This study compared the stability of the cervical spine according to the presence of neck pain and deep neck flexor performance. Thirty subjects with neck pain, and thirty subjects without neck pain were recruited for this study. The Cranio-cervical flexion (CCF) test was applied using a pressure biofeedback unit to classify the subjects into four subgroups; no cervical pain and good deep neck flexor performance (NG group), no cervical pain and poor deep neck flexor performance (NP group), cervical pain and good deep neck flexor performance (PG group), and cervical pain and poor deep neck flexor performance (PP group). The head sway angle was measured using a three-dimensional motion analysis system. A 3-kg weight was used for external perturbation with the subject sitting in a chair in the resting and erect head positions with voluntary contraction of the deep neck flexors. A one-way analysis of variance (ANOVA) was performed with a Bonferroni post hoc test. The deep neck flexor performance differed significantly among the four groups (p<.05). The NG group had significantly greater deep neck flexor performance than NP and PP groups. The stability of the cervical spine also differed significantly among the four groups in the resting head position (p<.05). The head sway angle was significantly smaller in NG group as compared with the other groups. The PP group had the greatest head sway angle in the resting head position. However, there was no significant difference in the stability of the cervical spine among the groups in the erect head position with voluntary contraction of deep neck flexors (p=.57). The results of this study suggest that the deep neck flexor performance is important for maintaining the stability of cervical spine from external perturbation.

• PNF and Movement
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• v.19 no.3
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• pp.321-329
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• 2021

Purpose: The abdominal drawing-in maneuver (ADIM) is an exercise that selectively strengthens deep abdominal muscles. It is reported to be effective in strengthening those muscles when using a pressure biofeedback unit. However, multiple factors of bridge exercise seem to bring exercise result of ADIM without stabilizer as they influence execution of ADIM. Therefore, the purpose of this study was to compare changes in the thickness of deep abdominal muscles through the ADIM exercise incorporating either a stabilizer or the bridge exercise. Methods: Thirty healthy adults who had voluntarily given their consent were selected as the subjects. A diagnostic sonograph was used to measure the thickness of the subjects' transverse abdominis, internal oblique, and external oblique muscles. First, the thickness of the subjects' deep abdominal muscle was measured while maintaining the ADIM using the stabilizer. After three minutes of rest, the thickness was measured again while the subjects maintained the ADIM with the bridge exercise. Results: In both exercises, the thickness of the transverse abdominis showed a statistically significant increase, with a more significant increase while executing the ADIM using the bridge exercise. In both exercises, the thickness of the internal oblique showed a statistically significant increase, with a more significant increase while executing the ADIM using the bridge exercise. The thickness of the external oblique showed a statistically significant increase only in the ADIM using the bridge exercise. Conclusion: Though strengthening is not as selective as the ADIM using a stabilizer, the ADIM using the bridge exercise has a more increased thickness of the transverse abdominis and the internal oblique than that of the internal oblique. Based on the outcome of this study, the ADIM using the bridge exercise without a stabilizer can selectively strengthen deep abdominal muscles even more.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.302-308
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• 2020

Objective: The endurance and strength of deep neck flexor (DNF) muscles have a major role on the function and stability of the cervical spine. In recent years, there has been a lack of research that have investigated the muscle tone of the superficial neck muscles. The purpose of this study was to examine the relationship of between contraction ratio of the DNF and sternocleidomastoid (SCM) muscles, DNF endurance, and muscle tension of the neck muscles. Design: Cross-sectional study. Methods: Forty-seven subjects (male=20, female=27) participated in this study. The muscle tone of the upper trapezius (UT), SCM, and suboccipital (SO) muscle was measured using a contact soft tissue tone-measuring instrument. For the contraction ratio of the SCM and longus colli muscle, the thickness of the relaxation and maximum contraction state of the SCM and longus colli muscles were assessed using a diagnostic ultrasound measuring instrument and a pressure biofeedback unit. The deep neck flexor endurance test (DNFET) was performed in a cranio-cervical flexion posture. The correlations between the measured variables were investigated. Results: The relationship between the DNFET and SO tone showed a significant negative correlation (p<0.05). The relationship between the DNFET and contraction ratio showed a significant positive correlation (p<0.01). There was no significant correlation between the DNFET and SCM and UT tone. Conclusions: This study confirmed that there is a relationship between DNF endurance, DNF activation, and SO tone. The information on the results of this study may be used as a reference that can be actively applied in the clinical environment.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.2
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• pp.189-195
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• 2019

Purpose : The purpose of this study was to investigate the effects of chin tuck exercise (CTE) on the craniovertebral angle (CVA), strength and endurance of deep cervical flexor (DCF) muscles in subjects with forward head posture(FHP). This study was performed on 30 subjects with FHP. Method : Thirty subjects were divided into two groups; modified CTE (n=15), conventional CTE (n=15). Both of the group performed the exercise 4 times a week for 6 weeks. The subjects performed CTE in two different methods; modified CTE, with device designed that help keep cervical lordois curve, and coventional CTE, without using device. The CVA was measured using Image software version. A pressure biofeedback unit was used to measure the strength and endurance of the DCF muscles. The data was analyzed by the paired t-test for comparing before and after changes of variables in each group and the independent t-test for comparing the between groups. Result : There was statistically significant difference of before and after strength and endurance of DCF muscles in modified CTE (p<0.05). There was statistically significant difference of before and after only endurance of DCF muscles in conventional CTE (p<0.05). There was statistically significant difference of between the two group in strength of DCF muscles (p<0.05). Conclusion : Muscle strength to stabilize the spine plays an important role in maintaining a good posture. Therefore, we suggest that the application of CTE with a device designed to maintain the lordotic curvature in the neck is likely to yield better outcomes in FHP subjects in future studies.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.3
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• pp.61-69
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• 2019

Purpose : The purpose of this study was to investigate the effects of Straight leg lifts (SLL) and double leg lowering (DLL) exercise on abdominal muscle activity, visual analog scale (VAS), and flexibility in patients with chronic low back pain (LBP). Methods : A total of 30 LBP patients were divided into two groups: those with SLL exercise group 15 (male=8, female=7) and those with DLL exercise group 15 (male=7, female=8). Before the intervention, the abdominal muscle activity, VAS, and flexibility were measured. After 4 weeks of intervention, the above variables were measured in the same way. The SLL exercise bends the leg $45^{\circ}$ in the supine position, and the DLL exercise was performed as opposed to SLL. At this time, the pressure biofeedback unit (PBU) was placed behind the lumbar to reduce the instability of the pelvis and muscles. The subjects were instructed to use the PBU to maintain the target pressure determined (40 mmHg) during the exercise. Results : The external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) were significantly different in the SLL and DLL group, and EO, IO, and TrA activity improved more significantly increased in the DLL than SLL group (p<.05). The results on the VAS and flexibility were significantly different both group (p<.05). However, there was no significant difference between the groups (p>.05). Conclusion : SLL and DLL exercises in patients with LBP were able to confirm the increased activity of the abdominal muscles, decreased pain, and increased flexibility of the waist. In addition, DLL exercise is more effective in patients with LBP in terms of muscle activity.

• Physical Therapy Korea
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• v.28 no.2
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• pp.138-145
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• 2021

Background: Forward head posture (FHP) causes various posture imbalances associated with the head and neck. Myofascial release is an effective treatment method used for relaxing muscles and reducing muscle hyperactivity, but no studies have been conducted on suboccipital and neck muscles related to FHP. Objects: The purpose of this study was to investigate the immediate effect of roller massages on the cranio-cervical flexion (CCF) range of motion (ROM) and CCF strength applied to suboccipital and neck muscles in subject with forward head posture. Methods: Twenty-four FHP subjects (male: 13, female: 11) were recruited for this study. All subjects were recruited with a craniovertebral angle (CVA) of 53 degrees or less and a head tilt angle (HTA) of 20.66 degrees or higher. CCF strength was measured using Pressure biofeedback unit (PBU) in the supine posture and CCF ROM was measured using smartphone-based inclinometer. Roller massage (RM) was applied to suboccipital and neck muscles for 2 minutes and CCF ROM and strength were remeasured. Results: These results of this study showed that CCF ROM was a significant difference in CCF ROM before and after RM (p < 0.05). CCF strength also showed a significant difference before and after RM (p < 0.05). Conclusion: RM method might be recommended to increase the immediate ROM and strength of CCF in subjects with forward head posture.