The Validity of Wireless Earbud-Type Wearable Sensors for Head Angle Estimation and the Relationships of Head with Trunk, Pelvis, Hip, and Knee during Workouts.

The present study was performed to investigate the validity of a wireless earbud-type inertial measurement unit (Ear-IMU) sensor used to estimate head angle during four workouts. In addition, relationships between head angle obtained from the Ear-IMU sensor and the angles of other joints determined with a 3D motion analysis system were investigated. The study population consisted of 20 active volunteers. The Ear-IMU sensor measured the head angle, while a 3D motion analysis system simultaneously measured the angles of the head, trunk, pelvis, hips, and knees during workouts. Comparison with the head angle measured using the 3D motion analysis system indicated that the validity of the Ear-IMU sensor was very strong or moderate in the sagittal and frontal planes. In addition, the trunk angle in the frontal plane showed a fair correlation with the head angle determined with the Ear-IMU sensor during a single-leg squat, reverse lunge, and standing hip abduction; the correlation was poor in the sagittal plane. Our results indicated that the Ear-IMU sensor can be used to directly estimate head motion and indirectly estimate trunk motion.

Classification-Specific Treatment Improves Pain, Disability, Fear-Avoidance Beliefs, and Erector Spinae Muscle Activity During Walking in Patients With Low Back Pain Exhibiting Lumbar Extension-Rotation Pattern: A Randomized Controlled Trial.

OBJECTIVE: Low back pain (LBP) has commonly been managed via classification-specific interventions in homogeneous groups. However, it is largely unknown whether treatment tailored to specific classifications is more effective than generic treatment. The purpose of this study was to evaluate the effects of classification-specific treatment on the self-reported responses and erector spinae (ES) activity of patients with LBP exhibiting a lumbar extension-rotation (ExtRot) pattern. METHODS: In total, 39 patients exhibiting the lumbar ExtRot pattern were randomized to an experimental (n = 19) group and a control (n = 20) group. Participants in the experimental group received classification-specific treatment, which included exercise to control or prevent lumbopelvic motion during lower-extremity movement. Participants in the control group were encouraged to perform general exercises and were educated about LBP. Patient-reported pain intensity, disability, and fear-avoidance belief and ES muscle activity during walking were assessed prior to and after the intervention. Two-way analysis of covariance was used to examine the effects of classification-specific treatment. RESULTS: After 6-week intervention, significant time-by-group interaction effects were demonstrated on pain intensity, disability, fear-avoidance beliefs-physical activity score, and ES muscle activity during walking. There were significant effects of group on pain, disability, and fear-avoidance beliefs-physical activity score after intervention. After the 6-week intervention, the ES muscle activity significantly decreased in the experimental group during walking, but does not represent an all-events decrease. CONCLUSION: Classification-specific treatment may be effective in patients with LBP exhibiting the lumbar ExtRot pattern, reducing pain intensity, disability, fear-avoidance beliefs, and ES muscle activity during walking.

Effects of Posterior X Taping on Movement Quality and Knee Pain Intensity during Forward-Step-Down in Patients with Patellofemoral Pain Syndrome.

Excessive tibiofemoral rotation in weight-bearing position may be associated with patellofemoral pain syndrome (PFPS). A previous literature suggested that "posterior X taping" method is effective for correcting the reduction of hip adduction and tibiofemoral rotation in weight bearing position. The purpose of this study was to determine the effects of posterior X taping on the angles of hip adduction, tibiofemoral rotation, grades of the forward-step-down (FSD) performance test, and intensity of knee pain when descending stair in patients with PFPS. We recruited patients with PFPS. The knee pain intensity during FSD was measured using visual analogue scale system (100 mm) under both no-tape and tape conditions. A three-dimensional motion analysis system was used to assess the kinematics of lower limb joints during FSD. In addition, scoring system of FSD performance test was used to assess the movement deviation of the trunk and lower limb and one-leg balance. Participants with PFPS showed reduced pain intensity (p = 0.001) and improved scores on FSD performance test (p = 0.002) with posterior X taping compared to the no-tape condition during FSD. No significant alterations changes were noted in three dimensional angles of the hip, knee and ankle joints, especially hip adduction and tibiofemoral rotation between conditions. Posterior X taping decreases knee pain and improves the scores on FSD performance test for patients with PFPS.

Effects of Motor Control Exercise Vs Muscle Stretching Exercise on Reducing Compensatory Lumbopelvic Motions and Low Back Pain: A Randomized Trial.

OBJECTIVES: The purpose of this study was to investigate the effectiveness of a 6-week motor control exercise (MCE) vs stretching exercise (SE) on reducing compensatory pelvic motion during active prone knee flexion (APKF) and intensity of low back pain. METHODS: Thirty-six people in the lumbar-rotation-extension subgroup were randomly assigned equally into 2 exercise groups (18 people in each an MCE or SE group). A 3-dimensional motion-analysis system was used to measure the range and onset time of pelvic motion and knee flexion during APKF. Surface electromyography was used to measure the muscle activity and onset time of the erector spinae and the hamstrings during APKF. The level of subjective low back pain was measured using a visual analog scale. RESULTS: The MCE group had more significant decreases in and delay of anterior pelvic tilt, pelvic rotation, and erector spinae muscle activity during APKF, as well as reduced intensity of low back pain compared with the SE group (P < .05). CONCLUSIONS: For rehabilitation in patients in the lumbar-rotation-extension subgroup, MCE was more effective than SE in reducing compensatory pelvic motion and muscle activity during APKF and minimizing low back pain.

Effects of controlled condylar rotation exercise on symmetrical mouth opening in patients with temporomandibular disorder.

[Purpose] The purpose of this study was to determine the effects of a 4-week program of active condylar rotation exercise on the extent of the lateral mandibular shift during mouth opening in patients with temporomandibular disorder. [Subjects and Methods] Patients with temporomandibular disorder (n = 12; 7 men and 5 women) were recruited. The active range of temporomandibular motion was recorded using 3-dimensional ultrasound-based motion analysis. The paired t-test was used to assess changes in lateral mandibular shift before and after active condylar rotation exercise. [Results] The degree of the lateral mandibular shift during mouth opening and the mouth opening-lateral mandibular shift ratio were significantly lower after active condylar rotation exercise than before the exercise. [Conclusion] Active condylar rotation exercise may effectively reduce the degree of the lateral mandibular shift during mouth opening to produce symmetrical mouth opening in patients with mild temporomandibular disorder.

Lumbopelvic motion during seated hip flexion in subjects with low-back pain accompanying limited hip flexion.

PURPOSE: Limited hip flexion may lead to a poor lumbopelvic motion during seated active hip flexion in people with low-back pain (LBP). The purpose of this study was to compare lumbopelvic motion during seated hip flexion between subjects with and without LBP accompanying limited hip flexion. METHODS: Fifteen patients with LBP accompanying limited hip flexion and 16 healthy subjects were recruited. The subjects performed seated hip flexion with the dominant leg three times. A three-dimensional motion-analysis system was used to measure lumbopelvic motion during seated hip flexion. RESULTS: During seated active hip flexion, the angle of hip flexion was significantly lower in patients with LBP accompanying limited hip flexion (17.4 ± 4.4 in the LBP group, 20.8 ± 2.6 in the healthy group; t = 2.63, p = 0.014). The angle of the lumbar flexion (4.8 ± 2.2 in the LBP group, 2.6 ± 2.0 in the healthy group; t = -2.96, p = 0.006) and posterior pelvic tilting (5.0 ± 2.6 in the LBP group, 2.9 ± 2.0 in the healthy group; t = 2.48 p = 0.019), however, were significantly greater in patients with this condition. CONCLUSIONS: The results of this study suggest that limited hip flexion in LBP can contribute to excessive lumbar flexion and posterior pelvic tilting during hip flexion in the sitting position. Further studies are required to confirm whether improving the hip flexion range of motion can reduce excessive lumbar flexion in patients with LBP accompanying limited hip flexion.

Comparison of the effects of local cryotherapy and passive cross-body stretch on extensibility in subjects with posterior shoulder tightness.

The objective was to compare the immediate effects of local cryotherapy (LC) and passive cross-body stretch on the extensibility of the posterior shoulder muscle in individuals with posterior shoulder tightness. Eighty-seven healthy subjects with a between-shoulder difference in internal rotation (IR) range of motion (ROM) greater than 10° were randomly divided into three groups: LC group, stretching group, and control group (n = 29 in each group). Subjects in the LC group received LC on infraspinatus and posterior deltoid muscles and subjects in the stretching group performed passive cross-body stretch. Stretch sensation was measured at the end range of passive IR and horizontal adduction (HA) using numerical rating scale, and the pressure pain threshold (PPT) at the infraspinatus and posterior deltoid muscles was measured using pressure algometry. Passive and active ROM of IR and HA of the glenohumeral joint were measured using an inclinometer. All measurements were performed at pre-intervention, post- intervention, and 10-min follow-up. Stretch sensation was significantly decreased and PPT was significantly increased in the LC and stretching groups at post-intervention, and these effects were maintained at 10-min follow-up, compared to the control group. Both the LC group and stretching group had a significantly greater increase in passive and active ROM of IR and HA, compared to the control group at post-intervention and 10-min follow-up. However, there were no significant differences in stretch sensation, PPT, or ROM of IR and HA between the LC group and stretching group. LC can be used to decrease the stretch sensation and increase PPT and ROM of IR and HA as much as a stretching exercise. LC could be an alternative method for increasing the restricted ROM of glenohumeral IR and HA for individuals with posterior shoulder tightness, especially for patients and sports players who have severe stretching discomfort. Key PointsLocal cryotherapy (LC) decreased the uncomfortable stretch sensation, and increased the pressure pain threshold (PPT) of infraspinatus and posterior deltoid muscles in subjects with posterior shoulder tightness.Decreased stretch sensation by LC without passive stretching could improve the passive and active ROM of internal rotation and horizontal adduction in subjects with posterior shoulder tightness, similar to cross-body stretch.LC can be an alternative method to increase extensibility when individuals with posterior shoulder tightness have high stretch sensitivity and low PPT in the infraspinatus and posterior deltoid muscles.

Influence of thoracic flexion syndrome on proprioception in the thoracic spine.

[Purpose] This study was performed to determine the difference in thoracic repositioning sense in young people with and without thoracic flexion syndrome (TFS) in target positions of half extension. [Subjects] People with TFS (n = 15; 7 men and 8 women) and people without TFS (n = 15; 7 men and 8 women) were recruited from three universities. Subjects were guided into a sitting extension target posture and were asked to move from a neutral position (2 s) to an extension target position (2 s); 10 trials were performed. [Results] People with TFS showed a significantly higher thoracic repositioning error in the extension target position than people without TFS. [Conclusion] People with TFS show a higher thoracic spine repositioning error in extension than people without TFS. A rehabilitation program to treat TFS should be implemented for individuals with decreased position sense of the thoracic spine.

Influence of Wearing a Brassiere on Pain and EMG Activity of the Upper Trapezius in Women with Upper Trapezius Region Pain.

[Purpose] This study examined the effect of wearing a brassiere on upper trapezius (UT) region pain and EMG activity during arm elevation by women. [Subjects and Methods] Fourteen healthy women were recruited. Surface EMG data were collected from the UT muscles during arm elevation. Pressure pain in the UT region was measured using a baseline dolorimeter. [Results] The EMG activity of the UT increased significantly when a brassiere was worn compared to without. UT region pain showed no significant difference between with and without wearing a brassiere. [Conclusion] This suggests that wearing a brassiere increases the muscle activation of the UT in women.

Effects of core stability and feedback music on upper body mediolateral movements during cycling.

BACKGROUND: Asymmetry in involuntary trunk motion during voluntary movements of the lower extremities is a risk factor for musculoskeletal injuries and may be related to core stability. Core stability plays a pivotal role in maintaining postural stability during distal segment movements. Because mediolateral head motion partially represents trunk motion during rhythmic movements, controlling it can help ensure symmetric trunk motion. This study aimed to investigate the relationship between core stability and asymmetric trunk motion during rhythmic movements, and to evaluate the effects of feedback music on mediolateral head motion. METHODS: We developed a system that uses a wireless earbud and a high-resolution inertial measurement unit sensor to measure head angle and provide feedback music. When the head angle exceeds a predefined threshold, the music is muted in the earbud on the side of the head tilt. In our lab-based study, we measured head angles during cycling at 70% of maximum speed using this self-developed system, and compared them between individuals with good (Sahrmann core stability test: 2-5 level) and poor core stability (0-1 level). The amplitude of mediolateral head motion was represented by the difference between the left and right peak angles, and the symmetry in mediolateral head motion was represented by the average of left and right peak angles. RESULTS: Individuals with poor core stability demonstrated significantly greater amplitude of, and less symmetry in, mediolateral head motion than those with good core stability. Additionally, feedback music significantly reduced the amplitude of mediolateral head motion in both the good- and poor-core-stability groups. CONCLUSION: Our findings indicate that core stability is crucial for maintaining symmetric head motion during rhythmic movements like cycling. Feedback music could serve as an effective tool for promoting symmetry in head motion and thus preventing musculoskeletal injuries.

Core stability status classification based on mediolateral head motion during rhythmic movements and functional movement tests.

Objective: Core stability assessment is paramount for the prevention of low back pain, with core stability being considered as the most critical factor in such pain. The objective of this study was to develop a simple model for the automated assessment of core stability status. Methods: To assess core stability-defined as the ability to control trunk position relative to the pelvic position - we used an inertial measurement unit sensor embedded within a wireless earbud to estimate the mediolateral head angle during rhythmic movements (RMs) such as cycling, walking, and running. The activities of muscles around the trunk were analyzed by an experienced, highly trained individual. Functional movement tests (FMTs) were performed, including single-leg squat, lunge, and side lunge. Data was collected from 77 participants, who were then classified into good and poor core stability groups based on their Sahrmann core stability test scores. Results: From the head angle data, we extrapolated the symmetry index (SI) and amplitude of mediolateral head motion (Amp). Support vector machine and neural network models were trained and validated using these features. In both models, the accuracy was similar across three feature sets for RMs, FMTs, and full, and support vector machine accuracy (∼87%) is greater than neural network (∼75%). Conclusion: The use of this model, trained with head motion-related features obtained during RMs or FMTs, can help to accurately classify core stability status during activities.

Comparison of electromyographic activity and range of neck motion in violin students with and without neck pain during playing.

Neck pain is common in violin students during a musical performance. The purpose of this study was to compare electromyographic (EMG) activity in superficial neck muscles with neck motion when playing the violin as well as neck range of motion (ROM) at rest, between violin students with and without neck pain. Nine violin students with neck pain and nine age- and gender-matched subjects without neck pain were recruited. Muscle activity of the bilateral upper trapezius, sternocleidomastoid, and superficial cervical extensor muscles was measured using surface EMG. Kinematic data on neck motion while playing and active neck ROM were also measured using a three-dimensional motion analysis system. Independent t-tests were used to compare EMG activity with kinematic data between groups. These analyses revealed that while playing, both the angle of left lateral bending and leftward rotation of the cervical spine were significantly greater in the neck pain group than among those without neck pain. Similarly, EMG activity of the left upper trapezius, both cervical extensors, and both sternocleidomastoid muscles were significantly greater in the neck pain group. The active ROM of left axial rotation was significantly lower in the neck pain group. These results suggest that an asymmetric playing posture and the associated increased muscle activity as well as decreased neck axial rotation may contribute to neck pain in violin students.

The Effect of a Pelvic Support Chair on Sagittal Lumbosacral Alignment in Sitting Position in Patients with Lower Back Pain.

Background: A slouched lumbar posture during sitting is risk factor for the low back pain (LBP). Various chairs have been used to maintain sagittal lumbar lordosis and sacral alignment during sitting. We aimed to demonstrate the effect of a pelvic-support chair on the lumbar lordosis and sacral tilt in patients with LBP. Methods: We recruited 29 patients with non-specific LBP and 11 healthy subjects in South Korea from Apr 2017 to Mar 2018. The sagittal lumbosacral alignment was examined radiographically in three sitting postures: usual, erect, and sitting in a pelvic-support chair. Five angles [the lumbar lordosis, upper lumbar (ULA), lower lumbar (LLA), lumbosacral (LSA), and sacral slope (SS) angles] were compared between the subjects with LBP and healthy subjects in the three sitting conditions. Results: There were significant differences in the lumbar lordosis, ULA, LLA, LSA, and SS according to sitting condition (P<.05). All five angles were significantly greater when participants sat erect or in a pelvic-support chair than in their usual sitting position (P<.05). ULA and SS were significantly greater when sitting erect than in a pelvic-support chair (P<.05). LLA was significantly greater in controls than in patients with LBP (P=.042). Conclusion: The sagittal alignment of the lumbosacral region differed significantly among usual, erect, and pelvic-support chair sitting in patients with LBP and controls. Decreased lordotic curve of the lumbar spine in the usual sitting position can be changed in both patients with LBP and healthy subjects by sitting with pelvic support chair.

Is lumbopelvic motor control associated with dynamic stability during gait, strength, and endurance of core musculatures?: The STROBE study.

Core stability has been described as the product of motor control and muscular capacity of the lumbopelvic-hip complex. Because of the wide range of functions of the lumbopelvic-hip complex, the gold standard for evaluating core stability remains controversial. The Sahrmann core stability test (SCST), used in conjunction with the stabilizer pressure biofeedback unit (PBU), is widely applied to objectively evaluate core stability as this pertains lumbopelvic motor control. However, the association between such control and other elements of core stability including core strength, endurance, and dynamic stability during gait has not been well-studied. We investigated the relationships among the ability to control the lumbopelvic complex, core strength and endurance, and gait parameters. We compared lateral core endurance, hip strengths, and gait parameters (lateral oscillation of the center of mass (COM), the single support time, and the peak ground reaction force) between good and poor core stability groups, as determined by the SCST. In addition, logistic regression analysis was used to determine whether other core stability measures correlated with the core stability status defined by the SCST. Only lateral oscillation of the COM during walking differed significantly between the good and poor core stability groups and was a significant predictor of SCST core stability status. Lumbopelvic motor control, (as defined by the SCST), affects dynamic stability during gait, but not to the strength or endurance of the core musculatures.

Consumer wearable device-based measures of physical activity and energy expenditure in community-dwelling older adults with different levels of frailty: A STROBE compliant study.

Physical activity is important for positive health outcomes, and wearable activity devices are useful for tracking physical activity patterns and energy expenditure. This study investigated differences in, and correlations of, duration of physical activity according to activity intensity and energy expenditure among community-dwelling older adults with different levels of frailty. This cross-sectional study enrolled 88 adults older than 65 years from communities between June 2019 and January 2020. The participants were divided into non-frail, pre-frail, and frail groups according to the frailty criteria. Outcomes included the frailty score, duration of physical activity according to the intensity of activity (sedentary, light, fairly active, fairly to very active, and very active), and energy expenditure measured by a consumer wearable device. The duration of physical activity according to the intensity of activity and energy expenditure were compared among non-frail, pre-frail, and frail groups. In addition, linear correlation analysis was used to identify significant associations of objectively measured physical activity and energy expenditure with frailty. Non-frail older adults showed significantly longer daily duration of light to very active physical activity and increased energy expenditure compared to the frail group (P < .05). Additionally, non-frail older adults engaged in significantly more light and fairly to very active physical activity, and showed increased energy expenditure, compared to the pre-frail group (P < .05). The non-frail group showed a significantly lower duration of sedentary behavior compared to the pre-frail group. Correlation analysis showed that frailty was significantly associated with decreased light to very active physical activity and energy expenditure, as well as increased sedentary behavior (P < .05). This study provides evidence of differences in objectively measured physical activity and energy expenditure between frail and non-frail older adults, and reveals an association of frailty with physical activity and energy expenditure. Daily physical activity that exceeds low-intensity, low-energy expenditure activity should be encouraged among older adults with frailty.

Effects of the abdominal drawing-in maneuver on muscle activity, pelvic motions, and knee flexion during active prone knee flexion in patients with lumbar extension rotation syndrome.

OBJECTIVE: To investigate the effects of performing an abdominal drawing-in maneuver (ADIM) during active prone knee flexion on the hamstrings and erector spinae muscle activity, the amounts of pelvic motion and knee flexion, and onset of pelvic movements. DESIGN: Comparative, repeated-measures study. SETTING: University research laboratory. PARTICIPANTS: Men patients (N=18) with lumbar extension rotation syndrome. INTERVENTION: Subjects performed prone knee flexion in 2 conditions. MAIN OUTCOME MEASURES: To measure muscle activity, surface electromyogram (EMG) of both erector spinae and the medial and lateral hamstrings was performed. Kinematic data on the pelvic motion and knee flexion were measured using a 3-dimensional motion analysis system. Repeated 1-way analysis of variance was used for the statistical analysis. RESULTS: Significantly decreased electromyographic activity in the right and left erector spinae and significantly increased electromyographic activity in the medial and lateral hamstrings activity were shown during prone knee flexion in ADIM condition using the pressure biofeedback unit. In addition, the amounts of anterior pelvic tilt, pelvic rotation, knee flexion, and perceived pain decreased significantly during prone knee flexion in the ADIM condition compared with the same maneuver in the non-ADIM condition. The onset of anterior pelvic tilt and pelvic rotation occurred significantly earlier in the non-ADIM condition, compared with the ADIM condition. CONCLUSIONS: ADIM effectively increased activation of knee flexors, decreased activation of back extensors, and reduced the pelvic motions and low back pain during prone knee flexion in patients with lumbar extension rotation syndrome.

Intertester and Intratester Reliability of Functional Movement Tests by Trained Testers in Community-Dwelling Older Adults With Knee Osteoarthritis: A Cross-sectional Study.

BACKGROUND AND PURPOSE: Movement quality of the lower extremities is considered an indicator of functional status in older adults with knee osteoarthritis (OA), and visual assessment of movement quality during functional movement tests can identify movement dysfunction and predict factors associated with lower extremity injuries. This study investigated the intertester and intratester reliability of trained testers for functional movement tests in community-dwelling older adults with knee OA. METHODS: This study was a cross-sectional study. A total of 43 older adults with knee OA were recruited for this study and performed 2 functional movement tests: squat and step-down. Movement quality during the functional movement tests was visually rated in segmental (trunk, pelvic, knee, and foot) and overall regions and was scored from 0 (acceptable) to 3 (marked dysfunction). Percentage of agreement and weighted κ coefficients were used to explore the reliability between and within testers. RESULTS: The intertester reliability of the functional movement tests showed weak to strong agreement (weighted κ values from 0.44 to 0.88); the percentage agreement ranged from 52.78% to 93.02%. The intratester reliability of the functional movement tests showed weak to strong agreement (weighted κ values from 0.57 to 0.88); the percentage agreement ranged from 69.77% to 93.02%. CONCLUSIONS: Visual assessment of functional movement tests showed weak to strong intertester and intratester reliability to examine movement quality in community-dwelling older adults with knee OA. Thus, while it may be useful in a clinical setting to assess movement dysfunction segmentally and generally in older adults with knee OA; greater efforts would be needed to ensure high levels of agreement of functional movement tests.

Prolonged sitting-induced back pain influences abdominal muscle thickness in a sitting but not a supine position.

The current study explored whether (i) abdominal muscle thickness differed between non-painful supine and painful sitting positions and (ii) the sitting position was more reliable and useful than the supine position to discriminate between people with and without prolonged sitting-induced lower back pain (LBP). Participants with and without prolonged sitting-induced LBP participated. The thickness of the transversus abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles was measured using ultrasonography in supine, usual sitting, and upright sitting positions. Analysis of variance was used to compare muscle thickness among the positions. Intraclass correlation coefficients and receiver operating characteristic curves were used to determine which position reliably identified between group. The group with LBP showed significantly greater EO muscle thickness than that without LBP only in the upright sitting position. In the group without LBP, the TrA thickness was significantly greater in the usual and upright sitting positions than in the supine position, but there was no significant difference in TrA thickness among three positions in LBP group. Only EO thickness in the upright sitting position significantly predicted prolonged sitting-induced LBP. The current study suggests that clinicians should assess abdominal activation patterns in the upright sitting rather than supine position before applying abdominal muscle motor control training for patients with prolonged sitting-induced LBP, and to distinguish between those with and without prolonged sitting-induced LBP.

Trapezius and serratus anterior muscle strength in violinists with unilateral neck pain.

BACKGROUND: Weakness of the trapezius and serratus anterior (SA) muscle may be a risk factor for unilateral neck pain. OBJECTIVE: This study examined the trapezius (upper, middle, and lower) and SA muscle strength ipsilateral and contralateral to the painful side in violinists with unilateral neck pain. METHOD: Twenty-six female violinists with unilateral neck pain participated in this study. Participants reported the pain intensity and duration and completed the Neck Disability Index (NDI). The strengths of the upper (UT), middle (MT), and lower (LT) trapezius and SA muscles were measured using a handheld dynamometer. Paired t-test was used to compare the strength of the muscles between ipsilateral and contralateral to the painful side within subjects. The relationship between pain intensity, pain duration, and neck disability and strength deficit of the muscle was demonstrated by Pearson's correlation and Spearman's rank correlation. RESULTS: The strengths of the UT, MT, LT, and SA muscles were significantly decreased on the painful side compared with the contralateral side (P< 0.05). Except for correlations between pain intensity and percent strength deficit of the UT and between pain duration and percent strength deficit of the MT (P< 0.05), there were no significant associations between pain intensity, pain duration, or NDI and the percent strength deficit of the UT, MT, LT and SA muscles (P> 0.05). CONCLUSIONS: These results suggest that decreased UT, MT, LT, and SA muscle strength on the side of the pain should be considered in the rehabilitation of violinists with unilateral neck pain.

Relationship between objectively measured lifestyle factors and health factors in patients with knee osteoarthritis: The STROBE Study.

The purpose of this study was to investigate the association between objectively-measured lifestyle factors and health factors in patients with knee osteoarthritis (OA).In this cross-sectional study, 52 patients with knee OA were examined. Lifestyle factors were measured using a wearable smartwatch (step counts, walking distance, calorie consumption, sleep hours) and by self-report (eating speed). Body mass index (BMI), waist circumference, blood pressure, muscle strength of knee extensor and hip abductor, knee pain, symptoms, daily living function, sports recreation function, quality of life by knee injury and OA outcome score (KOOS) were measured to obtain data on health factors. Correlations and regression analysis were used to analyze the relationship between lifestyle factors and health factors.KOOS subscales (pain, symptom, daily living function) and hip abductor strength were positively correlated with daily step count, which was the only independently contributing lifestyle factor. Additionally, knee pain duration and diastolic blood pressure were negatively correlated with daily step count. BMI and waist circumference showed no correlation with physical activity data, but were negatively correlated with sleep duration and eating speed.The findings of this study contribute to expanding the knowledge on how lifestyle habits of older patients with knee OA contribute to their health status. Daily step counts were associated with knee OA-related pain, symptom, function in daily living, duration of knee pain, blood pressure, and strength of hip abductor. BMI and waist circumference were associated with sleep duration and eating speed.