• Physical Therapy Korea
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• v.16 no.4
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• pp.1-7
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• 2009

The active-knee-extension (AKE) test has been used to measure hamstring muscle length. The traditional AKE test measures the popliteal angle to the point of resistance with a 90-degree flexion of the hip fixed by straps, while the stabilized AKE test measures the popliteal angle to the point of resistance with a 90-degree flexion of the hip stabilized using a pressure biofeedback unit providing lumbopelvic stabilization. The purpose of this study was to determine test-retest reliability of the traditional AKE test and stabilized AKE test. Twenty healthy adults participated in the study. The popliteal angles were measured with a digital inclinometer during each test. To assess the test-retest reliability between the 2 test sessions, intraclass correlation coefficients (ICCs) were calculated. The intrasubject coefficient of variation ($CV_{intra}$) was also calculated. To compare the traditional and stabilized AKE tests for changes in pressure, paired t-tests were applied. The results of this study were as follows: 1) ICCs(3,1) value for test-retest reliability was .96 in the traditional AKE test, and was .98 in the stabilized AKE test. 2) The maximal $CV_{intra}$ was 33.7% in the traditional AKE test and 15.7% in the stabilized AKE test. 3) Differences of $6.1{\pm}2.1$ mmHg in pressure were measured in the traditional AKE test, and differences of $1.2{\pm}1.0$ mmHg in pressure were measured in the stabilized AKE test. The results show the traditional and stabilized AKE test to be highly reliable, with test-retest reliability. However, the stabilized AKE test represented less variation and more stabilization than the traditional AKE test. Further study is needed to measure the inter-rater reliability of the stabilized AKE test for generalization and clinical application.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.2
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• pp.27-34
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• 2014

Background: This study examined the effects of cervical traction group and cervical traction & nerve mobilization exercise group after applying conservative physical therapy to Computer Workers with Cervical Radiculopathy. Methods: They were randomly divided into two groups: 18 subjects were cervical traction group, 22 subjects were cervical traction and nerve mobilization exercise group. Each group performed its own exercise 30 minutes per day, three times per week, for 4 weeks. Pain intensity was measured by the visual analogue scale (VAS) and neck disability index (NDI). Cervical extensor muscles strength (CEMS) was measured by the Pressure biofeedback unit. Grasping power (GP) was measured by the Grip Track Commander. Results: After 4 weeks therapy, VAS and NDI were significantly reduced in both groups (p<.05) and CEMS and GP were significantly increased in both groups (p<.05). Significant differences were also evident between the two groups for these three measurements (p<.05). Conclusions: cervical traction and nerve mobilization exercise group is more effective than cervical traction group for reducing VAS and NDI and increasing GP in computer workers with cervical radiculopathy.

• Physical Therapy Korea
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• v.14 no.4
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• pp.14-20
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• 2007

To improve abdominal muscles strengthening, double straight leg lowering (DSLL) has been widely used in physical therapy, fitness program, and athletic program. The purpose of this study was to investigate the effects of the lumbar stabilization maneuver with a pressure biofeedback unit on the muscle activity of rectus abdominis (RA), external oblique (EO), and internal oblique (IO) during DSLL. Fourteen healthy young men were recruited from university population. The electromyography (EMG) activity was recorded from the RA, EO, and IO of both sides. The normalized EMG activity was compared using a paired t-test. The study showed that EMG activity in the RA, EO, and IO was significantly higher during DSLL with lumbar stabilization (DSLL-LS) compared to performed DSLL (p<.05). These results suggest that DSLL-LS is recommended as an effective method for strengthening exercise for the abdominal muscles.

• The Journal of Korean Physical Therapy
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• v.31 no.2
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• pp.111-116
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• 2019

Purpose: This study examined the effects of horse riding simulator exercise on the thickness changes in the transverse abdominis in normal adults. Methods: Forty-five healthy adults were recruited and randomized to a horseback riding simulation exercise group (n=15), a sling exercise group (n=15), and a trunk stabilization exercise group (n=15). A horseback riding simulator offers the indoor experience of horseback riding and mimics the rhythmic movement of horseback riding, thereby provided a virtual environment, such as riding a real horse on the front screen. The velocity of the horse riding simulator exercise was regulated within the subject's ability to control the exercise on the horse riding simulator. A sling exercise group performed sling exercise under the inspection of the experimenter. In the trunk stabilization exercise group, the subjects were instructed to perform the exercise accurately and pause the session when pain occurred during the intervention. The subjects in each group carried out the interventions three times per week for six weeks. The thickness of the transverse abdominis was measured using a pressure biofeedback unit and the ultrasound. Results: Significant differences in the thickness of transverse abdominis within the groups were observed between before and after the interventions. On the other hand, there were no differences in the parameters among the groups. Conclusion: Horse riding simulator exercise can be an alternative to trunk stabilization exercise by increasing the thickness of the transverse abdominis in healthy adults.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.3
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• pp.107-113
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• 2021

PURPOSE: Selective strengthening of the transverse abdominis muscle (TrA) during abdominal hollowing makes an important contribution to the stability and control of the spine. This study examined the effects of abdominal hollowing exercise (AHE) according to the visual feedback method on the external oblique, internal oblique, and transverse abdominis muscles. METHODS: Twenty healthy subjects were assigned randomly to an AHE with visual feedback from real-time ultrasound image (group A, n = 10), AHE with visual feedback with pressure biofeedback unit (group B, n = 10). Both groups underwent 20 min of AHE with visual feedback once daily, five days/week for two weeks. The changes in the muscle thickness of the TrA, internal oblique abdominal muscle (IO), and external oblique abdominal muscle (EO) were measured by ultrasonography. RESULTS: The thickness of TrA was changed significantly in both groups (p < .05). However, the lowest minimal detectable changes were achieved in Group A. The thickness of the IO and EO muscles in group A was changed significantly, but there were no significant changes in group B. CONCLUSION: Both visual feedback methods were effective for strengthening the TrA muscles selectively. Nevertheless, AHE with visual feedback using real-time ultrasound images may be more useful in trA muscle contraction.

• 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.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.