Background: Delivery workers repeatedly get in and out of trucks and walk or run to deliver packages during work. Iliotibial band syndrome (ITBS) is a well-known non-traumatic overuse injury of the lateral side of the knee caused by frequent knee flexion and extension. Hip muscle strength is among the factors that prevent lower extremity injuries. Although many studies have examined the relationship between ITBS and hip muscle strengths, there was no study comparing hip muscle strength and ratio between delivery workers with and without ITBS. Objects: This study aimed to compare hip muscle strength and hip internal/external rotator and adductor/abductor strength ratios between delivery workers with and without ITBS. Methods: Fourteen delivery workers with ITBS matched inclusion criteria in the present study among 20 participants. Because total sample size was required 28 subjects by G*power program (ver. 3.1.9.4; University of Trier), 14 delivery workers without ITBS were recruited. Hip muscle strengths were measured in a side-lying position using a Smart KEMA pulling sensor (KOREATECH Co. Ltd.). An independent t-test was used to compare hip muscle strengths and hip internal/external rotator and hip adductor/abductor strength ratios between delivery workers with and without ITBS. Results: The adductor/abductor strength ratio was significantly greater in delivery workers without ITBS than in those with ITBS (p < 0.05). The strengths of the hip abductor, hip adductor, hip internal rotator, hip external rotator, and the ratio of internal/external rotator strengths were not significantly different between the delivery workers with and without ITBS (p > 0.05). Conclusion: This study’s findings showed that delivery workers with ITBS had significantly lesser adductor/abductor strength ratio, while the strengths of the hip abductor and adductor muscles did not differ significantly. These results suggest that adductor/abductor strength ratio should be considered when evaluating and treating ITBS in delivery workers.

Background: Trunk movements are an important factor in activities of daily living; however, these movements can be impaired by stroke. It is difficult to quantify and measure the active range of motion (AROM) of the trunk in patients with stroke. Objects: To determine the reliability and validity of measurements using a digital goniometer (DG) and smart phone (SP) applications for trunk rotation and lateral flexion in stroke patients. Methods: This is an observational study, in which twenty participants were clinically diagnosed with stroke. Trunk rotation and lateral flexion AROM were assessed using the DG and SP applications (Compass and Clinometer). Intrarater reliability was determined using intraclass correlation coefficients (ICCs) with 95% confidence intervals. Pearson correlation coefficient was used to determine the validity of the DG and SP in AROM measurement. The level of agreement between the two instruments was shown by Bland–Altman plot and 95% limit of agreement (LoA) was calculated. Results: The intrarater reliability (rotation with DG: 0.96–0.98, SP: 0.98; lateral flexion with DG: 0.97–0.98, SP: 0.96) was excellent. A strong and significant correlation was found between DG and SP (rotation hemiplegic side: r = 0.95; non-hemiplegic side: r = 0.90; lateral flexion hemiplegic side: r = 0.88; non-hemiplegic side: r = 0.78). The level of agreement between the two instruments was rotation (hemiplegic side: 23.02° [LoA 17.41°, –5.61°]; non-hemiplegic side: 31.68° [LoA 23.87°, –7.81°]) and lateral flexion (hemiplegic side: 20.94° [LoA 17.48°, –3.46°]; non-hemiplegic side: 27.12° [LoA 18.44°, –8.68°]). Conclusion: Both DG and SP applications can be used as reliable methods for measuring trunk rotation and lateral flexion in patients with stroke. Although, considering the level of clinical agreement, DG and SP could not be used interchangeably for measurements.

Background: The craniocervical flexion test (CCFT) was developed for the activation and endurance of deep cervical flexors. However, the muscle thickness and muscle thickness changing ratio of the sternocleidomastoid (SCM) and deep cervical flexor (DCF) muscles in subjects with and without forward head posture (FHP) have not been reported. Objects: To determine the difference in thickness of the SCM and DCF muscles and the difference in the muscle thickness changing ratio between SCM, DCF, and DCF/SCM 20 mmHg and DCF/SCM 30 mmHg between subjects with and without FHP. Methods: Thirty subjects with and without FHP were enrolled. The muscle thickness of the SCM and DCF was measured when maintained at a baseline pressure of 20 mmHg and a maximum pressure of 30 mmHg using a pressure biofeedback unit during the CCFT. Ultrasonography was used to capture images of SCM and DCF muscle thickness during the CCFT, which was calculated using the picture archiving and communication system (PACS). Results: We observed a significant difference within the pressure main effect between SCM and DCF at a baseline pressure of 20 mmHg and a maximum pressure of 30 mmHg (p < 0.05). However, there was no significant difference in the muscle thickness and muscle thickness changing ratio for SCM and DCF during CCFT between subjects with and without FHP. Conclusion: There was no significant difference in the muscle thickness recruitment pattern during CCFT in posture changes between subjects with and without FHP.

Background: Considering the kinetic chain of the lower extremity, a pronated foot position (PFP) can affect malalignment of the lower extremity, such as a dynamic knee valgus (DKV). Although the DKV during several single-leg movement tests has been investigated, no studies have compared the differences in DKV during a single-leg step down (SLSD) between subjects with and without PFP. Objects: The purpose of this study was to compare the DKV during SLSD between subjects with and without PFP. Methods: Twelve subjects with PFP (9 men, 3 women) and 15 subjects without PFP (12 men, 3 women) participated in this study. To calculate the DKV, frontal plane projection angle (FPPA), knee-in distance (KID), and hip-out distance (HOD) during SLSD were analyzed by twodimensional video analysis software (Kinovea). Results: The FPPA was significantly lower in PFP group, compared with control group (166.4° ± 7.5° and 174.5° ± 5.5°, p < 0.05). Also, the KID was significantly greater in PFP group, compared with control group (12.7 ± 3.9 cm and 7.3 ± 2.4 cm, p < 0.05). However, the HOD not significantly differed between two groups (12.7 ± 1.7 cm and 11.4 ± 2.5 cm, p > 0.05). Conclusion: The PFP is associated with lower FPPA and greater KID. When assess the DKV during SLSD, the PFP should be considered as a crucial factor for occurrence of DKV.

Background: Whole-body vibration (WBV) has been used to alleviate proprioceptive damage by musculoskeletal and neurological conditions. However, no study has determined whether wearing shoes while applying WBV can affect proprioception precision of the knee joint. Objects: This study aimed to determine the differences in the proprioceptive precision of the knee joint before and after WBV and to compare the proprioceptive precision of the knee joint between barefoot and shoe-wearing conditions. Methods: This study recruited 33 healthy participants. A passive-to-active angle reproduction test was used to measure the proprioception precision of the knee joint using an electrogoniometer, and the target angle was set to a knee flexion of 30°. Proprioception precision was calculated using the error angle (angular difference from 30°). Proprioceptive precision was measured in weight-bearing and non-weight-bearing positions before and after applying WBV for 20 minutes at 12 Hz in barefoot and shoe-wearing conditions. Mixed repeated analysis of variance was used to determine the differences in changes in the proprioceptive precision of the knee joint according to foot conditions. Results: There were significant improvements in the weight-bearing (p = 0.002) and nonweight- bearing (p < 0.001) proprioceptive precision of the knee joint after applying WBV. However, there was no significant difference in the change in proprioceptive precision of the knee joint after applying WBV between the barefoot and shoe-wearing conditions. Conclusion: WBV stimulation had an immediate effect on improving the proprioceptive precision of the knee joint. However, foot conditions (barefoot or shoe-wearing) during WBV application did not influence the proprioceptive precision of the knee joint.

Background: Anterior cruciate ligament reconstruction (ACLR) causes a reduction in the balance of the lower extremities. Static and dynamic balance were evaluated separately to confirm the decrease in balance in patients underwent ACLR. The commonly used methods include the Biodex Balance System (BBS) for static balance and the Y balance test (YBT) for dynamic balance. No study has evaluated whether the static and dynamic balance of the involved side recovers as much as the uninvolved side one year after ACLR. Objects: The purpose of this study was to investigate the recovery of static and dynamic balance between the involved and the uninvolved sides. Methods: The BBS (overall, anteroposterior index, and mediolateral index) and YBT (anterior, posterolateral, and posteromedial) of 58 patients underwent ACLR were measured one year postoperation. Both sides of the BBS and the YBT were compared using the paired t-test. Results: All the index of the BBS showed no difference between the involved and the uninvolved sides, while all the scores of the YBT showed a significant difference in both sides. The YBT anterior result was 54.64 ± 5.62 cm in the involved side and 56.90 ± 5.41 cm in the uninvolved side (p = 0.001). The YBT posterolateral results were 90.12 ± 10.51 cm and 92.34 ± 9.85 cm (p = 0.013). The YBT posteromedial results were 93.72 ± 8.84 cm and 96.14 ± 9.37 cm (p = 0.002). Conclusion: A year after ACLR, the static balance showed no difference, while the dynamic balance showed a significant difference in the involved and the uninvolved sides. The static balance of the involved side recovered as much as the uninvolved side, but the dynamic balance did not. Therefore, dynamic balance training should be considered in the rehabilitation program for patients underwent ACLR.

Background: Forward head posture (FHP) is common postural malalignment. FHP is described relatively extension to upper cervical and lower cervical is relatively flexion. Although several researchers mentioned the lower cervical flexion posture in FHP, most of the studies related to FHP is focused on the deep cervical flexor function. Objects: The purposes of present study is to compare the cervical strength (upper cervical extension [UCE], lower cervical extension [LCE], upper cervical flexion [UCF], lower cervical flexion [LCF]) between individuals with and without FHP. Methods: Fifty-one participants are recruited. Participants who have the craniovertebral angle (CVA) less than 48 degree were classified to the FHP group (n = 24) and the others were included in without FHP group (n = 27). The cervical strength (UCE, LCE, UCF, LCF) were measured using Smart KEMA strength sensor and the strength data was normalized by body weight. All strength measurement conducted at head and neck neutral position in sitting. Independent t-test was used to compare the cervical strength between individuals with and without FHP. Results: The mean value of CVA was greater in without FHP group than with FHP group (p < 0.000). The strength value of UCF (p < 0.002) and LCE (p < 0.001) was significant less in FHP group than without FHP group. But no significant differences were seen in the LCF and UCE strength between two groups. Conclusion: UCF and LCE weakness in FHP group should be considered to evaluate and manage the individuals with FHP.

Background: The hip muscle plays various roles. Several types of functional performance tests are used for the assessment of patients with various lower extremity injuries. Hip muscle functions are important to test the performance of maintaining the spine, pelvic, and leg during bridging exercise. We designed a novel functional performance test tool, which we named close kinetic chain dynamic lower extremity stability (CKCLE) test to assess hip muscle functions. Objects: The purpose of this study was to determine the relationship between CKCLE test and hip extensor, external rotator, and abductor strengths. Methods: Twenty-two subjects were recruited in the present study (13 males and 9 females). The hip extensor, external rotator, and abductor muscle strengths were measured using a Smart KEMA strength sensor. When the examiner said “Go”, the subject performed the CKCLE test by moving one leg from the floor and touching the opposite knee and then return to the floor while maintaining the bridging position. The subjects attempted as many “touches” as possible in the allotted time (20 seconds) during the maximal tests. The correlation between the hip muscle (extensor, external rotator, and abductor) strength of the supporting leg and the number of CKCLE tests performed in 20 seconds was determined using the Pearson correlation. Results: Hip extensor (r = 0.626, p < 0.05), hip external rotator (r = 0.616, p < 0.05), and hip abductor muscle strengths (r = 0.475, p < 0.05) positively correlated with the number of CKCLE tests performed. Conclusion: We designed a CKCLE test and found that performance in the test correlated with hip extensor, external rotator, and abductor muscle strengths. The result suggests that the CKCLE test can be applied as a performance test to assess the functions of the hip extensor, external rotator, and hip abductor muscles.

Background: The wall squat exercise has been recommended for strengthening of the lower extremity muscles with maintaining lumbar lordosis. Although squat has been studied to be related to lower extremity extensor strength, the relationship between wall squat and lower extremity extensor strength unclear. Because squat and wall squat are biomechanically different, study on the relationship is needed. Objects: The purpose of this study was to determine the lower extremity extensor strength associated with wall squat performance. Methods: 74 healthy volunteers were recruited to participate in this study. The volunteers were measured hip and knee extensors strength and then performed wall squat exercise for maximum count. Results: We found significant relationships between wall squat performance and hip extensor strength normalized by body weight, knee extensor strength normalized by body weight and the composite value. In a regression analysis, hip extensor strength normalized by body weight explained 29% of the variation in wall squat performance in males and 35% in females. Conclusion: These results demonstrate that hip extensor strength normalized by body weight is critical to wall squat performance in both sexes.

Background: Stress urinary incontinence (SUI) is an involuntary leakage of urine from the urethra when intra-abdominal pressure increases, such as from sneezing, coughing, or physical exertion. It is caused by insufficient strength of the pelvic floor and sphincter muscles, resulting from vaginal delivery, obesity, hard physical work, or aging. The pelvic floor electrical stimulator is a conservative treatment generally used to relieve the symptoms of urinary incontinence. it recommended to applied before surgery is performed. Objects: The purpose of this study was to determine if the transcutaneous electrical stimulation (TCES) would be effective for the physiological symptoms and psychological satisfaction of women with SUI for an 8-weeks intervention. Methods: Easy-K is a specially designed user-friendly TCES. Five female who were diagnosed with SUI by a gynecologist but who did not require surgical intervention were included in this study. Intervention was implemented over an 8-week period. Outcome measures included vaginal ultrasonography, Levator ani muscle (LAM) contraction strength, incontinence quality of life (I-QOL), and female sexual function index (FSFI) questionnaires. Results: The bladder neck position significantly decreased across assessment time. Funneling index and urethral width significantly decreased after 8 weeks of intervention (p<.05). The bladder necksymphyseal distance and posterior rhabdosphincter thickness statistically increased and the anterior rhabdosphincter thickness showed a tendency to increase. All participants demonstrated a significant increase in the LAM contraction score across three assessment times (p<.05). Although the total score of the I-QOL did not show significant improvement, it steadily increased and among I-QOL subscales, only the “avoidance” subscale showed statistical improvements (p<.05). The total score of the FSFI statistically improved and the “desire” score significantly changed (p<.05). Conclusion: The TCES is recommended for women who want to apply conservative treatments before surgery and who have suffered from SUI in aspects of sexual function and quality of life.

Background: The craniocervical flexion (CCF) exercise is one of the effective exercise in correcting forward head posture (FHP). However, some people with FHP achieve CCF with compensatory movements, for example, low cervical flexion using superficial neck flexors such as the sternocleidomastoid (SCM) muscle. No study has yet investigated whether a dualpressure biofeedback unit (D-PBU) method to prevent low cervical flexion would be helpful in performing pure CCF movement. Objects: The purpose of this study was to compare the effects of the CCF using D-PBU method and the traditional CCF method on the cross-sectional area (CSA) of the longus colli muscle (LCM) and the activity of SCM muscle in subjects with FHP. Methods: Twentyfour FHP subjects (male: 16, female: 8) were recruited for this study. All subjects performed CCF using two different methods: The traditional CCF method and the CCF using D-PBU method. The CSA of the LCM was measured via ultrasound, and surface electromyography was used to measure SCM muscle activity. Results: The change in CSA of the LCM was significantly larger during the CCF using D-PBU method (1.28±.09) compared with the traditional CCF method (1.19±.08) (p<.05). The SCM muscle activity using the CCF using D-PBU method (2.01±1.97 %MVIC) was significantly lower than when using the traditional CCF method (2.79±2.32 %MVIC) (p<.05). Conclusion: The CCF using D-PBU method can be recommended for increasing LCM activation and decreasing SCM muscle activity during CCF movement in subjects with FHP.

Background: Shoulder external rotation exercises are commonly used to improve the stabilizing ability of the infraspinatus. Although the side-lying wiper exercise (SWE) is the most effective shoulder external rotation exercise to maximize infraspinatus activity, the effect of adduction force on the infraspinatus and posterior deltoid has not been demonstrated. Objects: This study was conducted to investigate whether horizontal adduction force increases infraspinatus activity and decreases posterior deltoid activity. Methods: Twenty-eight healthy subjects (male: 21, female: 7; age=23.5±1.8 years; height=170.1±7.4 ㎝; weight=69.4±9.6 ㎏) were recruited. Subjects were asked to perform the SWE under two conditions: (1) general SWE and (2) SWE with adduction force using pressure biofeedback. Surface electromyography (EMG) signals of the infraspinatus and posterior deltoid were recorded during SWE. Paired t-tests were used to compare the EMG activity of the infraspinatus and posterior deltoid between the two conditions. Results: Posterior deltoid muscle activity was significantly decreased following SWE with adduction force (7.53±4.52%) relative to general SWE (11.68±8.42%) (p<.05). However, there was no significant difference in the infraspinatus muscle activity between the SWE with adduction force (28.33±12.16%) and the general SWE (26.54±13.69%) (p>.05). Conclusion: Horizontal adduction force while performing SWE is effective at decreasing posterior deltoid activity.

Background: The serratus anterior (SA) muscle is one of the important muscles in the upward rotation of the scapula when the arm is raised. Insufficient muscle activity of the SA can cause deformation of the shoulder rhythm resulting in shoulder pathology. Objects: This study intends to compare SA and upper trapezius (UT) activity during the conventional wall-slide and push-up plus exercises for SA muscle strengthening and the scapular upward rotation (SUR) exercise. Methods: A total of 30 subjects participated in this study, and we measured the muscle activity of the SA and UT muscles during the wall-slide, push-up plus and SUR exercises. The one-way repeated ANOVA was used to compare SA and UT muscle activities during the 3 exercises. Results: During the SUR exercise, SA muscle activity was 79.88% maximum voluntary isometric contraction (MVIC), which was significantly higher than its activity during the other 2 exercises. The UT muscle activity was 47.53 %MVIC during the SUR exercise, indicating a significantly higher UT muscle activity than during the other 2 exercises. Conclusion: These findings suggest that the SUR exercise can maximize SA muscle activity to strengthen the SA while keeping UT muscle activity at an appropriate level.

Background: The wall squat is considered an effective exercise because it can reduce the knee load and prevent excessive lumbar movement. However, the relationship between wall squat performance and strength of knee extensors and hip extensors remained unclear. Objects: The purpose of this study was to compare the strengths of the knee extensors and hip extensors between groups with low and high wall squat performance. Method: Nineteen males (low performance group: 9 subjects, high performance group: 10 subjects) participated in this study and performed wall squats. The subjects who were performing less than 30% of the average wall squat count were classified into the low wall squat performance group (less than or equal to 4 times) and the subjects who performed more than 30% of the average wall squat count were classified into the high wall squat performance group (greater than or equal to 8 times). Knee extensor and hip extensor strength were measured with a strength measurement system. An independent t-test was used to compare the strengths of the knee extensors and hip extensors between the groups with low and high wall squat performance. Results: The ratios of knee extensor and hip extensor strength to bodyweight were greater in the high wall squat performance group than in the low wall squat performance group (knee extensors: p<.001; hip extensors: p=.03). In the high- and low-performance groups, the ratios of knee extensor strength to bodyweight were 42.74±5.72 and 30.76±8.54, respectively, and the ratios of hip extensor strength to bodyweight were 31.95±10.61 and 20.66±11.25, respectively. Conclusion: Our findings suggest that knee extensor and hip extensor strength are needed for high wall squat performance. Thus, exercise to increase the knee and hip extensors strength can be recommended to improve squat performance.

Background: The functioning of the serratus anterior (SA) muscle is essential to normal scapulohumeral rhythm during forward flexion (FF) of the shoulder. Also, SA weakness and overuse of the upper trapezius (UT) is observed in patients with shoulder dysfunction and trapezius myalgia. We designed a combination exercise involving FF and scapular protraction with resistance (CFFSP) to activate the SA muscle and to deactivate the UT muscle. Objects: The purpose of this study was to determine whether or not CFFSP would be more effective in activating the SA muscle than FF alone and FF with scapular protraction (FFP). Methods: Nineteen subjects (12 men and 7 women) participated in this study and performed FF, FFP, and CFFSP at 120°. Surface electromyography was applied to the SA, UT, and pectoralis major (PM) muscles, as was one-way analysis of variance (ANOVA) with repeated measures. Statistical significance was set at .05. Bonferroni adjustment was used to counteract the problem of multiple comparisons, with a statistical level of significance of .017 (.05/3). Results: A statistically significant difference was found in relation to the three positions for the SA muscle (p<.001) and the SA/UT ratio (p=.005) using ANOVA. Significantly different results, depending on the position, were also demonstrated using the Bonferroni post-hoc test for the SA muscle (FF=28.27±16.20, FFP=45.66±15.81, and CFFSP=62.4±27.21) and for the SA/UT ratio (FF=3.04±2.14, FFP=3.61±2.38, and CFFSP=5.95±3.01). Significant differences between the three positions was not found regarding the average amplitude of SA/PM muscle ratio (SA/PM: p=.060). Conclusion: We recommend the use of CFFSP to strengthen the SA muscle at 120°.

Background: Various methods are used for recovery of knee flexion range of motion (ROM) due to a tightened rectus femoris muscle (RFM) or limited inferior glide of the patella. Stretching methods are common interventions for restoring the tightened RFM length. Also patellar inferior gliding (PIG) technique can recover tightened RFM length too. However, effect of applying the PIG to passive knee flexion (PKF) has not been studied. Objects: The purpose of this study was to investigate the effect of combining PIG with RFM stretching for improving knee flexion ROM in subjects with RFM tightness. Methods: Twenty-six subjects with RFM tightness were recruited. Two different methods of knee stretching were tested: 1) PKF during modified Thomas test (MTT) and 2) PKF with PIG during MTT. The passive stretching forces was controlled by hand-held dynamometer. The knee flexion ROM angle was measured by a MTT with ImageJ software. Differences between the conditions with and without PIG were identified with a paired t-test. Results: The knee flexion ROM was significantly greater for PKF with PIG (114.44±9.33) than for PKF alone (108.97±9.42) (p<.001). Conclusion: A combination of passive knee flexion exercise and PIG can be more effective than PKF in increasing knee flexion ROM in individuals with RFM tightness.

Background: Shoulder horizontal adduction (HA) is performed in many activities of daily living. The limited range of motion (LROM) of HA is affected by the tightness of the posterior deltoid, infraspinatus, teres major, and posterior capsule of glenohumeral joint. The LROM of shoulder HA contributes to excessive scapular abduction. Objects: The aim of this study is to compare the scapular abduction distance and three-dimensional displacement of the scapula during shoulder horizontal adduction between subjects with and without the LROM of shoulder HA. Methods: 24 subjects (12 people in LROM group and 12 people in normal ROM group) participated. Subjects with less than 115° of HA ROM were included in LROM group. Shoulder HA was performed 3 times for measuring scapular abduction distance and three-dimensional displacement of the scapula. Tape measure was used for measuring scapular abduction distance. Scapular abduction distance was normalized by dividing the scapular size. Polhemus Liberty was used for measuring the three-dimensional displacement of the scapula. Results: Normalized scapular abduction distance was significantly greater in LROM group than normal ROM group (p<.001). Three-dimensional displacement of the scapula during shoulder HA was greater in LROM group than normal ROM group (p<.05). Conclusion: LROM group had a greater scapular abduction and three-dimensional displacement of the scapula during shoulder HA compared to normal ROM group.

Background: Prone hip extension (PHE) can be performed to measure the lumbopelvic motor patterns and motions. Imbalances in lumbopelvic muscle activity and muscle weakness can result in instability including pain in lumbopelvic region. The posterior oblique sling (POS) muscles contribute to dynamic lumbopelvic stability. In addition, POS are anatomically aligned with the trapezius muscle group according to shoulder positions. Objects: This study compared the electromyography (EMG) activity of POS and pelvic compensations during PHE with and without pre-activation of lower trapezius muscle (lowT). Methods: Sixteen healthy males were recruited. PHE was performed in randomized order: PHE with and without lowT pre-activation. Surface EMG signals were recorded for biceps femoris (BF), gluteus maximus (GM) (ipsilateral), lumbar multifidus (MF) (bilateral), and the lowT (contralateral). An electromagnetic tracking motion analysis was used to measure the angle of pelvic rotation and anterior tilting. Results: The ipsilateral GM and bilateral MF EMG amplitudes were greater during PHE with lowT pre-activation compared to PHE without lowT pre-activation (p<.05). The BF amplitude during PHE without lowT pre-activation was significantly greater than that during PHE with lowT pre-activation (p<.05). The angles of pelvic rotation and anterior tilting during PHE with lowT pre-activation were significantly smaller compared to PHE without lowT pre-activation (p<.05). Conclusion: PHE with lowT pre-activation, which is aligned with the POS, showed more increased MF and GM muscular activity with smaller lumbopelvic compensations in rotation and anterior tilting compared to PHE without lowT pre-activation.

The aims of the current study were to assess reliability of range of motion (ROM) measurement of glenohumeral internal rotation (GIR) with a pressure biofeedback stabilization (PBS) method and to compare the reliability between manual stabilization (MS) and the PBS method. In measurement of pure glenohumeral joint motion, scapular stabilization is necessary. The MS method in GIR ROM measurement was used to restrict scapular motion by pressing the palm of the tester’s hand over the subject’s clavicle, coracoid process, and humeral head. The PBS method was devised to maintain consistent pressure for scapular stabilization during GIR ROM measurement by using a pressure biofeedback unit. GIR ROM was measured by 2 different stabilization methods in 32 subjects with GIR deficit using a smartphone clinometer application. Repeated measurements were performed in two test sessions by two testers to confirm inter- and intra-rater reliability. After tester A performed measurements in test session 1, tester B’s measurements were conducted one hour later on the same day to assess the inter-rater reliability and then tester A performed again measurements in test session 2 for confirming the intra-rater reliability. Intra-class correlation coefficient (ICC) (2,1) was applied to assess the inter-rater reliability and ICC (3,1) was applied to determine the intra-rater reliability of the two methods. In the PBS method, the intra-rater reliability was excellent (ICC=.91) and the inter-rater reliability was good (ICC=.84). The inter-rater and intra-rater reliability of the PBS method was higher than in the MS method. The PBS method could regulate manual scapular stabilization pressure in inter- and intra-rater measuring GIR ROM. Results of the current study recommend that the PBS method can provide reliable measurement data on GIR ROM.

This study compared the effects of the initial head position (i.e., a HHP versus a relaxed head position) of subjects with and without a FHP on the thickness of the deep and superficial neck flexor muscles during CCF. The study recruited 6 subjects with a FHP and 10 subjects without a FHP. The subjects performed CCF in two different head positions: a HHP, with the head aligned so that the forehead and chin formed a horizontal line, and a relaxed head position (RHP), with the head aligned in a self-selected comfortable position. During the CCF exercise, the thickness of the longus colli (LCo) and the thickness of the sternocleidomastoid (SCM) were recorded using ultrasonography. The thickness of each muscle was measured by Image J software. The statistical analysis was performed with a two-way mixed-model analysis of variance. The thickness of the SCM differed significantly (p<.05) between the subjects with and without FHP. According to a post hoc independent t-test, the change in thickness of the SCM increased significantly during CCF in the subjects with FHP while adopting a HHP compared to that in the subjects without FHP. The change in thickness of the SCM was not significantly different between the two positions in subjects without FHP, and there was no significant change in thickness of the LCo muscle during the CCF exercise according to the initial position in both subjects with and without FHP. The results suggest that CCF should be performed in RHP to minimize contraction of the SCM in subjects with a FHP.