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.

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.

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.

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.

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.

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.

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.

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.

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.

Shoulder Pain and Rotational Range of Motion of the Trunk, Shoulder, and Hip in Baseball Players.

CONTEXT: Deficient glenohumeral rotational range of motion (ROM) is a risk factor for shoulder pain. Adapted ROM of the trunk and hip in response to loss of glenohumeral ROM has been suggested, as the nature of baseball leads to ROM adaptations. OBJECTIVE: To compare the bilateral rotational ROM values of the trunk and glenohumeral and hip joints in adolescent baseball players with or without shoulder pain and to measure the correlation between shoulder-pain intensity and bilateral rotational ROM values for each body area. DESIGN: Cross-sectional study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Ninety-five adolescent baseball players (60 with shoulder pain, 35 without shoulder pain). MAIN OUTCOME MEASURE(S): Bilateral trunk rotation and internal rotation, external rotation, and total rotation of the dominant and nondominant glenohumeral and hip joints. RESULTS: Glenohumeral and hip ROM did not differ between groups, and pain intensity and rotational ROM were not related in either joint. Trunk rotational ROM was greater in the pain group than in the control group (dominant side = 48.8° ± 14.2° versus 41.8° ± 11.9°, respectively; nondominant side = 45.1° ± 14.2° versus 38.9° ± 7.7°, respectively; P values < .05), although the difference was clinically small (mean differences = 7.0° ± 2.7° [95% confidence interval = 1.7, 12.4] on the dominant side, P = .01, and 6.1° ± 2.7° [95% confidence interval = 0.8, 11.5] on the nondominant side, P = .03). Positive but low correlations in all players (ρ = 0.27, P = .01) and in those with shoulder pain (ρ = 0.36, P = .001) were present between shoulder-pain intensity and trunk rotational ROM toward the dominant side. CONCLUSIONS: We found no clinical relationship between shoulder pain and rotational ROM and no clinical differences in rotational ROM values between players with and those without shoulder 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.

Comparison of hip extensor muscle activity including the adductor magnus during three prone hip extension exercises.

OBJECTIVES: This study compared the role of the adductor magnus muscle (Amag) as a hip extensor while performing active prone hip extension (PHE), PHE with hip adduction (PHE-ADD), and PHE with hip abduction (PHE-ABD) with the gluteus maximus (Gmax) and hamstrings. METHODS: The study recruited 22 healthy participants. Electromyography data were recorded from the Amag, Gmax, and medial and lateral hamstrings during PHE, PHE-ADD, and PHE-ABD. Normalized electromyographic data were examined using one-way, repeated-measures analyses of variance. RESULTS: The magnitude of the Amag, Gmax, and hamstring activations did not differ significantly while performing PHE (p = 0.41). Furthermore, the Amag and hamstring activations were significantly greater than the Gmax activation when performing PHE-ADD (p < 0.05). The Gmax showed significantly greater activation during PHE-ABD than the Amag and medial and lateral hamstrings (p < 0.05). CONCLUSIONS: Based on these results, we advocate including the Amag as a hip extensor during the PHE test or exercise. Our preliminary results have the potential to be applied directly to the PHE test, for investigating the muscle-activation pattern of the Amag with the Gmax and hamstrings in patients with hip or lower back pain.

Effects of knee taping during functional activities in older people with knee osteoarthritis: A randomized controlled clinical trial.

AIM: The purpose of the present study was to examine the effects of knee taping on perceived pain, difficulty and stability during functional activities (squat, step-down, and stair up and down) in older adults with knee osteoarthritis (OA). METHODS: A total of 50 older participants with knee OA participated in this study. The experimental group received non-elastic taping (NET) and the control group received sham taping. Perceived knee pain on an 11-point scale (0 = no pain, 10 = worst pain), and difficulty (1 = no difficulty, 5 = extreme difficulty) and stability (1 = no unstable, 5 = extreme unstable) on a 5-point scale during functional tests (squat, step-down test, and stair up and down) were reported at baseline and post-taping application. RESULTS: At post-taping, pain intensity, difficulty and stability during squat, step-down test, and stair up and down were significantly improved in the NET group. In the control group, there was significant decreased pain intensity during squat and stair up and down; however, there were no significant change of other variables. Compared with the control group, the NET significantly improved perceived pain, difficulty and stability during all tasks after the taping application. CONCLUSIONS: The present study showed that NET application can improve perceived pain intensity, difficulty and stability during functional tests in older adults with knee OA. NET can be recommended to improve pain, stability and difficulty during squat, step-down, and stair up and down in older adults with OA. Geriatr Gerontol Int 2018; 18: 1206-1210.

Description and Intrarater Test-Retest Reliability of a Reverse-Action Method to Assess Ankle Evertor Muscle Performance: The I-to-V Test.

Purpose: Reverse action (RA) of the ankle evertor muscle is when the proximal attachment moves toward the distal attachment, moving the lower leg in the frontal plane when the foot and ankle are fixed on the ground and inducing ankle eversion. The purpose of this study was to describe an RA method for measuring ankle evertor muscle performance. Method: Eighteen healthy individuals were recruited for this study. To assess the RA of their ankle evertors, the participants sat with their knees together and their feet firmly planted on the floor, then spread their knees as far apart as possible. A tester used a measuring tape to measured the distance (in cm) between the medial tibial tuberosity of the tested side and that of the non-tested side. In the end range position of the RA, ankle evertor electromyographic activity was recorded simultaneously. The intra-class correlation coefficient (ICC) and standard error of measurement (SEM) were calculated to establish the intrarater test-retest reliability. The correlation between each performance value and muscle activity was assessed using a linear correlation model. Results: The proposed method of assessing RA performance was highly reliable (ICC=0.95) and had a low SEM (1.63 cm); in addition, the performance value showed a strong positive correlation with ankle evertor muscle activity (ρ=0.90; 95% CI: 0.79, 0.95; p=0.01). Conclusions: The proposed RA method of assessing the ankle evertor muscles can be used as a simple, reliable, economical performance test. It can also be used as an alternate method of testing the peroneal muscles rather than selectively measuring ankle evertor performance because hip external rotation occurs when performing RA.

Objectif : lors de l'inversion du muscle éverseur de la cheville, l'attache proximale se déplace vers l'attache distale et, si le pied est posé à plat sur le sol, la jambe inférieure se place dans le plan frontal et on observe une éversion de la cheville. La présente étude vise à décrire une méthode d'inversion pour mesurer le rendement du muscle éverseur de la cheville. Méthodologie : les chercheurs ont recruté 18 personnes en bonne santé. Pour évaluer l'inversion des éverseurs de la cheville, les participants se sont assis, ont rapproché les genoux et posé les pieds à plat sur le sol, puis ont écarté les jambes le plus largement possible. À l'aide d'un ruban à mesurer, un évaluateur a mesuré la distance, en centimètres, entre la tubérosité tibiale médiane du côté testé et celle du côté non testé. En inversion maximale, l'activité électromyographique des éverseurs de la cheville était enregistrée simultanément. Les chercheurs ont calculé le coefficient de corrélation interne (CCI) et l'écart-type de la mesure (ÉTm) pour établir la fiabilité intraévaluateur du test-retest. Ils ont évalué la corrélation entre chaque valeur de rendement et l'activité musculaire au moyen du modèle de corrélation linéaire. Résultats : la méthode proposée pour évaluer le rendement de l'inversion était très fiable (CCI=0,95) et l'ÉTm était, faible (1,63 cm). De plus, la valeur de rendement a révélé une corrélation positive solide avec l'activité du muscle éverseur de la cheville (ρ=0,90; intervalle de confiance à 95 %=0,79, 0,95; p=0,01). Conclusion : la méthode d'inversion proposée pour évaluer les muscles éverseurs de la cheville est un test de rendement simple, fiable et économique. Elle peut également être utilisée pour tester les muscles péroniers plutôt que pour mesurer sélectivement le rendement de l'éverseur de la cheville en raison de la rotation externe de la hanche pendant l'inversion.

Pain intensity and abdominal muscle activation during walking in patients with low back pain: The STROBE study.

Nonspecific low back pain (LBP) is a common musculoskeletal problem that is intensified during physical activity. Patients with LBP have been reported to change their abdominal muscle activity during walking; however, the effects of pain intensity, disability level, and fear-avoidance belief on this relationship have not been evaluated. Thus, we compared abdominal muscle activity in patients with LBP and asymptomatic controls, and assessed the impact of pain intensity, disability level, and fear-avoidance belief.Thirty patients with LBP divided into groups reporting low (LLBP) and high-pain intensity low back pain (HLBP), and 15 participants without LBP were recruited. LBP patients' self-reported pain intensity, disability, and fear-avoidance belief were recorded. To examine abdominal muscle activity (rectus abdominis [RA], internal [IO], and external oblique [EO] muscles) during walking, all subjects walked at a self-selected speed. Abdominal muscle activity (RA, IO, and EO) was compared among groups (LLBP, HLBP, and controls) in different phases of walking (double support vs swing). Relationships between abdominal muscle activity and clinical measures (pain intensity, disability, fear-avoidance belief) were analyzed using partial correlation analysis.Right IO muscle activity during walking was significantly decreased in LLBP and HLBP compared with controls in certain walking phase. Partial correlation coefficients showed significant correlations between fear-avoidance belief and right EO activity (r = .377, P < .05) and between disability index and left IO activity (r = .377, P < .05) in patients with LBP. No significant difference was found in abdominal muscle activity in walking between patients with LLBP and HLBP (P > .05).This study demonstrated decreased IO muscle activity during certain walking phases in LLBP and HLBP compared with asymptomatic participants. Although altered IO muscle activity during walking was observed in patients with LBP, no changes were found with other abdominal muscles (EO, RA). Thus, these results provide useful information about abdominal muscle activity during walking in patients with LBP.

Asymmetry of neck motion and activation of the cervical paraspinal muscles during prone neck extension in subjects with unilateral posterior neck pain.

BACKGROUND: Although unilateral posterior neck pain (UPNP) is more prevalent than central neck pain, little is known about how UPNP affects neck motion and the muscle activation pattern during prone neck extension. OBJECTIVE: To investigate whether deviation in neck motion and asymmetry of activation of the bilateral cervical paraspinal muscles occur during prone neck extension in subjects with UPNP compared to subjects without UPNP. METHODS: This study recruited 20 subjects with UPNP and 20 age- and sex-matched control subjects without such pain. Neck motion and muscle onset time during prone neck extension were measured using a three-dimensional motion-analysis system and surface electromyography. RESULTS: The deviation during prone neck extension was greater in the UPNP group than in the controls (p < 0.05). Compared with the controls, cervical extensor muscle activation in the UPNP group was significantly delayed on the painful side during prone neck extension (p < 0.05). CONCLUSIONS: Subjects with UPNP showed greater asymmetry of neck motion and muscle activation during prone neck extension compared with the controls. This suggests that UPNP has specific effects on neck motion asymmetry and the functions of the cervical extensors, triggering a need for specific evaluation and exercises in the management of patients with UPNP.

An immediate effect of axial neck rotation training with real time visual feedback using a smartphone inclinometer on improvement in axial neck rotation function.

OBJECTIVES: The purpose of this study was to compare the immediate effects of axial neck rotation training (Axi-NRT) with and without real-time visual feedback (VF) using a smartphone inclinometer on the range of motion (ROM) for axial neck rotation and the onset of compensatory neck lateral bending and extension during active neck rotation. METHODS: Twenty participants with restricted ROM for neck rotation but no neck pain (21.1 ± 1.6 years and 8 males, 12 females) were recruited for Axi-NRT with VF, and twenty age- and gender-matched participants with restricted ROM for neck rotation were recruited for Axi-NRT without VF. Changes in ROM for neck rotation and the onset time of compensatory neck movement during active neck rotation were measured using an electromagnetic tracking system. RESULTS: Axi-NRT with VF was more effective in increasing ROM for neck rotation and decreasing and delaying the onset of compensatory neck movements during active neck rotation compared with Axi-NRT without VF. CONCLUSIONS: Repeated Axi-NRT using VF is useful to educate participants in maintaining the axis of the cervical spine and to increase ROM for axial neck rotation with less compensatory neck motion in participants with a restricted range of neck rotations.

Leg lateral reach test: The reliability and correlation with thoraco-lumbo-pelvic rotation range.

OBJECTIVES: The aim of the present study was to examine the intra- and inter-rater reliabilities of the leg lateral reach test as a screening tool for thoraco-lumbo-pelvic rotation and to assess the relationship between leg lateral reach distance and thoraco-lumbo-pelvic rotation range in a supine position. DESIGN: Controlled laboratory study. METHODS: Thirty-six physically active participants were recruited. The leg lateral reach test was performed over 2 days. In the first session, two testers measured the distance of the leg lateral reach to determine the within-day inter-rater reliability, and one tester repeated the measurement on day 2 to determine the intra-rater reliability between days. The leg lateral reach test was performed three times per leg, and the mean value was used for data analysis. Reliability was determined using the intraclass correlation coefficient, standard error of measurement, and minimal detectable change. The correlation between leg lateral reach distance and thoraco-lumbo-pelvic rotation range was determined using Pearson correlation. RESULTS: Almost perfect intra- and inter-rater reliabilities were shown for the test [intraclass correlation coefficient2,3=0.97 (95% confidence interval=0.914-0.984) and 0.99 (0.974-0.996), respectively]. The within-day inter-rater standard error of measurement was 1.40cm, and the minimal detectable change was 3.87cm. The between-day intra-rater standard error of measurement was 2.66cm, and the minimal detectable change was 7.37cm. The Pearson correlation showed a moderate to good correlation between the leg lateral reach distance and the thoraco-lumbo-pelvic rotation range (r=0.73). CONCLUSIONS: The leg lateral reach screening test is reliable for measuring thoraco-lumbo-pelvic rotation range and allows for practical measurement of the thoraco-lumbo-pelvic rotation range in a supine position.