Machine learning models for classifying non-specific neck pain using craniocervical posture and movement

OBJECTIVE

Physical therapists and clinicians commonly confirm craniocervical posture (CCP), cervical retraction, and craniocervical flexion as screening tests because they contribute to non-specific neck pain (NSNP). We compared the predictive performance of statistical machine learning (ML) models for classifying individuals with and without NSNP using datasets containing CCP and cervical kinematics during pro- and retraction (CKdPR).

DESIGN

Exploratory, cross-sectional design.

SETTING AND PARTICIPANTS

In total, 773 public service office workers (PSOWs) were screened for eligibility (NSNP, 441; without NSNP, 332).

METHODS

We set up five datasets (CCP, cervical kinematics during the protraction, cervical kinematics during the retraction, CKdPR and combination of the CCP and CKdPR). Four ML algorithms-random forest, logistic regression, Extreme Gradient boosting, and support vector machine-were trained.

MAIN OUTCOME MEASURES

Model performance were assessed using area under the curve (AUC), accuracy, precision, recall and F1-score. To interpret the predictions, we used Feature permutation importance and SHapley Additive explanation values.

RESULTS

The random forest model in the CKdPR dataset classified PSOWs with and without NSNP and achieved the best AUC among the five datasets using the test data (AUC, 0.892 [good]; F1, 0.832). The random forest model in the CCP dataset had the worst AUC among the five datasets using the test data [AUC, 0.738 (fair); F1, 0.715].

CONCLUSION

ML performance was higher for the CKdPR dataset than for the CCP dataset, suggesting that ML algorithms are more suitable than classical statistical methods for developing robust models for classifying PSOWs with and without NSNP.

Unsupervised machine learning for clustering forward head posture, protraction and retraction movement patterns based on craniocervical angle data in individuals with nonspecific neck pain

OBJECTIVES

The traditional understanding of craniocervical alignment emphasizes specific anatomical landmarks. However, recent research has challenged the reliance on forward head posture as the primary diagnostic criterion for neck pain. An advanced relationship exists between neck pain and craniocervical alignment, which requires a deeper exploration of diverse postures and movement patterns using advanced techniques, such as clustering analysis. We aimed to explore the complex relationship between craniocervical alignment, and neck pain and to categorize alignment patterns in individuals with nonspecific neck pain using the K-means algorithm.

METHODS

This study included 229 office workers with nonspecific neck pain who applied unsupervised machine learning techniques. The craniocervical angles (CCA) during rest, protraction, and retraction were measured using two-dimensional video analysis, and neck pain severity was assessed using the Northwick Park Neck Pain Questionnaire (NPQ). CCA during sitting upright in a comfortable position was assessed to evaluate the resting CCA. The average of midpoints between repeated protraction and retraction measures was considered as the midpoint CCA. The K-means algorithm helped categorize participants into alignment clusters based on age, sex and CCA data.

RESULTS

We found no significant correlation between NPQ scores and CCA data, challenging the traditional understanding of neck pain and alignment. We observed a significant difference in age (F = 140.14, p < 0.001), NPQ total score (F = 115.83, p < 0.001), resting CCA (F = 79.22, p < 0.001), CCA during protraction (F = 33.98, p < 0.001), CCA during retraction (F = 40.40, p < 0.001), and midpoint CCA (F = 66.92, p < 0.001) among the three clusters and healthy controls. Cluster 1 was characterized by the lowest resting and midpoint CCA, and CCA during pro- and -retraction, indicating a significant forward head posture and a pattern of retraction restriction. Cluster 2, the oldest group, showed CCA measurements similar to healthy controls, yet reported the highest NPQ scores. Cluster 3 exhibited the highest CCA during protraction and retraction, suggesting a limitation in protraction movement.

DISCUSSION

Analyzing 229 office workers, three distinct alignment patterns were identified, each with unique postural characteristics; therefore, treatments addressing posture should be individualized and not generalized across the population.

Prediction Model of Subacromial Pain Syndrome in Assembly Workers Using Shoulder Range of Motion and Muscle Strength Based on Support Vector Machine

Subacromial pain syndrome (SAPS) is the most common upper-extremity musculoskeletal problem among workers. In this study, a machine learning model was built to predict and classify the presence or absence of SAPS in assembly workers with shoulder joint range of motion (ROM) and muscle strength data using support vector machine (SVM). Permutation importance was used to determine important variables for predicting workers with or without SAPS. The accuracy of the support vector classifier (SVC) polynomial model for classifying workers with SAPS was 82.4%. The important variables in model construction were internal rotation and abduction of shoulder ROM and internal rotation of shoulder muscle strength. It is possible to accurately perform SAPS classification of workers with relatively easy-to-obtain shoulder ROM and muscle strength data using this model. In addition, preventing SAPS in workers is possible by adjusting the factors affecting model building using exercise or rehabilitation programs.

Respiratory Parameters as Predictors of Balance and Gait Ability in Patients with Stroke at Discharge

Pulmonary complications are frequent in stroke, contributing to both mortality and morbidity rates. Respiratory parameters in such patients encompass both pulmonary function and respiratory muscle strength. Identifying respiratory function variables that influence the balance and gait ability of patients with stroke is crucial for enhancing their recovery in these aspects. However, no study has assessed predictions for a comprehensive array of balance and gait abilities in such patients. We aimed to examine whether initial respiratory muscle strength and pulmonary function can predict balance and gait ability at discharge from a rehabilitation program. Thirty-one patients with stroke were included in this prospective observational study. Multiple regression models with a forward selection procedure were employed to identify respiratory parameters (including peak expiratory flow and maximal expiratory pressure) that contributed to the results of balance assessments and gait evaluations at the time of discharge. The peak expiratory flow (PEF) served as a predictor explaining 42.0% of the variance. Similarly, the maximal expiratory pressure (MEP) was a predictor variable explaining 32.0% of the variance. PEF and MEP assessments at the initial stage as predictive factors for both balance and gait ability are important in stroke management.

Effect of pelvic floor muscle electrical stimulation on lumbopelvic control in women with stress urinary incontinence: randomized controlled trial

INTRODUCTION

The pelvic floor muscle (PFM) plays a role not only in lumbopelvic stabilization, but also in incontinence and sexual function.

OBJECTIVE

This study aimed to determine the effectiveness of PFM training by electrical stimulation (ES) on urinary incontinence, PFM performance (i.e. strength and power), lumbopelvic control, and abdominal muscle thickness in women with stress urinary incontinence (SUI).

METHODS

Participants were randomized into ES and control groups. The ES group underwent PFM ES for 8 weeks, whereas the control group underwent only a walking program. The impact of urinary incontinence on quality of life was assessed by the Incontinence Impact Questionnaire (IIQ)-7. PFM strength and power were measured using a perineometer. Lumbopelvic control was measured by one and double-leg-lowering tests. Abdominal muscle thickness was measured by sonography.

RESULTS

The ES group showed significantly improved IIQ-7 scores and PFM performance, and had significantly higher values in both one and double-leg lowering tests (p < .05) after 8 weeks of training, indicating significant improvement from pre-session values (p < .005). There were no significant between- or within-group differences at rest in abdominal muscle thickness.

CONCLUSION

PFM ES could improve lumbopelvic control and PFM performance, and reduce subjective symptoms of urinary incontinence in women with SUI.

Investigating the Anti-Aging Effects of Caviar Oil on Human Skin

BACKGROUND/AIM

As the largest organ of the human body, the skin serves as a critical barrier against environmental damage. However, many factors, such as genetics, sun exposure, and lifestyle choices can lead to skin damage creating wrinkles, sagging, and loss of elasticity. The use of skincare products containing natural ingredients has become increasingly popular as a way to combat the signs of aging. Caviar oil is one such ingredient that has gained attention due to its rich composition of fatty acids, vitamins, and minerals. The objective of this study was to investigate the potential anti-aging effects of caviar oil and to develop a product, Cavi Balm, which could potentially reduce wrinkles and skin sagging.

MATERIALS AND METHODS

An in vitro model using the 3T3-L1 cell line was employed to assess the effect of caviar oil on adipocyte differentiation. An ex vivo study using human skin tissue was conducted to investigate the impact of caviar oil on collagen and elastin formation and the expression of matrix metalloproteinase-1,2,9 (MMP-1, MMP-2, MMP-9). Furthermore, 102 participants were enrolled in five clinical studies to evaluate the anti-aging efficacy of our product, "Cavi Balm", in facial and neck wrinkles, facial and eye area lifting, and various skin parameters, such as skin moisture, skin elasticity, skin density, skin tightening relief, skin clarity, and skin turnover.

RESULTS

In vitro, caviar oil enhanced adipocyte differentiation, and increased lipid accumulation inside the cells. The ex vivo analysis revealed that caviar oil reduced the expression levels of MMP-1, MMP-2, and MMP-9, and increased the formation of elastin and collagen I, III. Moreover, in the clinical study, Cavi Balm improved skin parameters after one-time use, with more significant effects observed after four weeks of usage.

CONCLUSION

Caviar oil has a substantial impact on mitigating skin aging and holds potential for application in anti-aging products.

Relationship between female sexual function, vaginal volume, vaginal resting tone, and pelvic floor muscle strength in women with stress urinary incontinence

Objective

Vaginal morphology and pelvic floor muscle (PFM) strength may influence sexual stimulation, sensation, and orgasmic response. This study aimed to determine the relationship between female sexual function and PFM strength and vaginal morphology (represented by vaginal resting tone and vaginal volume) in women with stress urinary incontinence (SUI).

Methods

Forty-two subjects with SUI were recruited for the study. Female sexual function was measured using the female sexual function index (FSFI) questionnaire. PFM strength was measured by digital palpation. Vaginal resting tone (mmHg) and vaginal volume (mL) were measured using a perineometer. The significance of the correlations between female sexual function and PFM function and hip muscle strength was assessed using Pearson's correlation coefficients. If a significant correlation between vaginal morphology and FSFI score was confirmed using Pearson's correlation, the cutoff value was confirmed through a decision tree.

Results

PFM strength was significantly correlated with desire (r=0.397), arousal (r=0.388), satisfaction (r=0.326), and total (r=0.315) FSFI scores. Vaginal resting tone (r=-0.432) and vaginal volume (r=0.332) were significantly correlated with the FSFI pain score. The cutoff point of vaginal resting tone for the presence of pain-related sexual dysfunction was >15.2 mmHg.

Conclusion

PFM strength training should be the first strategy to improve female sexual function. Additionally, because of the relationship between vaginal morphology and pain-related sexual dysfunction, surgical procedures to achieve vaginal rejuvenation should be carefully considered.

Comparison of acromiohumeral distance and glenohumeral internal rotation angle between the empty can test and modified empty can test: "thumb pointing down" versus "elbow pointing laterally"

BACKGROUND

During the empty can test, the direction of the thumb (downward) has been widely used as an instruction for producing glenohumeral internal rotation. However, the combination of forearm pronation and thumb motion as a compensatory movement could contribute to the lack of glenohumeral internal rotation during the empty can test. This study aimed to compare the glenohumeral internal rotation angle between the conventional empty can (with thumb direction) and modified empty can tests (with elbow direction), as well as the acromiohumeral distance between the full can, conventional empty can, and modified empty can tests.

METHODS

In this laboratory study, we measured the glenohumeral internal rotation angle using a motion sensor and the acromiohumeral distance using ultrasonography during the following tests: full can test (thumb pointing up), conventional empty can test (thumb pointing down), and modified empty can test (elbow pointing laterally) in 20 healthy subjects.

RESULTS

Compared with the conventional empty can test, the glenohumeral internal rotation angle was significantly greater during the modified empty can test (p < 0.05). Furthermore, the acromiohumeral distance measured in the modified empty can test was significantly less than that in the full can test (p < 0.001) and conventional empty can test (p < 0.001). However, there was no difference in the acromiohumeral distance between the full can test and the conventional empty can test (p > 0.017).

CONCLUSIONS

During the empty can test, the instructions should be given to patients based on the elbow direction (elbow pointing laterally). The modified empty can test can produce full glenohumeral internal rotation, compared with instructions based on the thumb direction (thumb pointing down). Consequently, the modified empty can test can produce a more decreased subacromial space.

Effect of electrical stimulation training and detraining on abdominal muscle function

BACKGROUND

Electrical muscle stimulation (EMS) has been applied in many rehabilitation settings for muscle strengthening, facilitation of muscle contraction, re-education of muscle action, and maintenance of muscle strength and size during prolonged immobilization.

OBJECTIVE

The purpose of this study was to investigate effect of 8 weeks of EMS training on abdominal muscle function and to determine whether the training effect could be maintained after 4 weeks of EMS detraining.

METHODS

Twenty-five subjects performed EMS training for 8 weeks. Before and after 8 weeks of EMS training, and after 4 weeks of EMS detraining, muscle size (cross-sectional area [CSA] of the rectus abdominals [RA] and lateral abdominal wall [LAW]), strength, endurance, and lumbopelvic control (LC) were measured.

RESULTS

There were significant increases in CSA [RA (p< 0.001); LAW (p< 0.001)], strength [trunk flexor (p= 0.005); side-bridge (p< 0.05)], endurance [trunk flexor (p= 0.010); side-bridge (p< 0.05)], and LC (p< 0.05) after 8 weeks of EMS training. The CSA of the RA (p< 0.05) and the LAW (p< 0.001) were measured after 4 weeks of detraining and they were greater than that of the baseline. There were no significant differences in abdominal strength, endurance, and LC between baseline measurements and post-detraining.

CONCLUSION

The study indicates that there is less of a detraining effect on muscle size than on muscle strength, endurance, and LC.

Correlation between trunk rotation and lateral flexion range of motion, peak cough flow, and chest expansion in stroke patients

INTRODUCTION

Stroke patients have problems with voluntary movement and trunk control. Moreover, the respiratory function in stroke patients is affected by neurological impairment, which increases the incidence of respiratory complications.

OBJECTIVES

To determine the correlation between trunk rotation range of motion (TRROM) and trunk lateral flexion range of motion (TLFROM), peak cough flow (PCF), and chest expansion in stroke patients.

METHODS

This was an observational study involving 21 patients with a clinical diagnosis of stroke from October 2021 to January 2022. TRROM and TLFROM were assessed using smartphone applications (Compass and Clinometer), respectively, PCF was assessed using a peak flow meter, and chest expansion was assessed using a tape measure. Pearson's correlation was used to analyze the relationships between the variables.

RESULTS

Statistically significant correlations were found between TRROM and TLFROM (r = 0.91, p < 0.01) and between upper chest expansion and PCF (r = 0.59, p < 0.01). There were significant correlations between lower chest expansion and TRROM (r = 0.50, p < 0.05) and between lower chest expansion and TLFROM (r = 0.51, p < 0.05).

CONCLUSION

This study demonstrates the relationship between upper chest expansion and PCF. Upper chest expansion exercises should be considered to improve the PCF in stroke patients. In addition, a very strong positive correlation between TRROM and TLFROM was demonstrated. TRROM and TLFROM exercises should be considered to improve the lower chest expansion in stroke patients.

Influencing factors of pressure pain hypersensitivity of the upper trapezius in food service workers with nonspecific neck/shoulder myofascial pain: A cross-sectional study

It is unclear which factors contribute to the developing pressure pain hypersensitivity of the upper trapezius, a type of neurophysiological hyperexcitability. The present study investigated the relationship between physical and psychological factors and pressure pain hypersensitivity of the upper trapezius for each sex. In total, 154 individuals with neck/shoulder myofascial pain participated, among 372 food service workers. Participants completed a questionnaire (Beck Depression Inventory, and Borg Rating of Perceived Exertion scale) and were photographed to measure posture. Pressure pain sensitivity, 2 range of motions (cervical lateral bending and rotation), and 4 muscle strengths (serratus anterior, lower trapezius [LT], biceps, and glenohumeral external rotator) were measured by a pressure algometer, iPhone application, and handheld dynamometer, respectively. For each sex, forward multivariate logistic regression was used to test our a priori hypothesis among selected variables that a combination of psychosocial and physical factors contributed to the risk for pressure pain hypersensitivity. In multivariate analyses, LT strength (odds ratio = 0.94, 95% confidence interval = 0.91-0.97, P = .001) was the only significant influencing factor for pressure pain hypersensitivity in men. Dominant painful ipsilateral cervical rotation range of motion (odds ratio = 0.96, 95% confidence interval = 0.92-0.99, P = .037) was the only influencing factor for pressure pain hypersensitivity in women. LT strength and dominant painful ipsilateral cervical rotation range of motion could serve as guidelines for preventing and managing pressure pain hypersensitivity of the upper trapezius in food service workers with nonspecific neck/shoulder myofascial pain.

Effect of improved thoracic kyphosis on forward shoulder posture after mobilization in individuals with thoracic hyperkyphosis

BACKGROUND

Thoracic hyperkyphosis structurally alters the position of the scapula to cause forward shoulder posture. However, the effect of improved thoracic hyperkyphosis on forward shoulder posture is unclear. The objective of this study was to determine the effect of eight weeks of thoracic mobilization on improving thoracic hyperkyphosis and forward shoulder posture and determine the cutoff change ratio in kyphosis for improving forward shoulder posture using the decision tree method.

METHOD

This study included 19 participants with thoracic hyperkyphosis who underwent thoracic mobilization for eight weeks. Forward shoulder posture (acromion-to-the-wall index) and thoracic kyphosis were measured before and after thoracic mobilization.

FINDINGS

The intervention significantly improved thoracic kyphosis and forward shoulder posture. The cutoff change ratio in kyphosis for improving forward shoulder posture was >13.79%. In the subgroup analysis of participants with a change ratio of kyphosis >13.79% (seven cases), all patients showed improved forward shoulder posture. In contrast, in the subgroup with a change ratio of kyphosis ≤13.79% (12 cases), eight cases showed improved forward shoulder posture, while four cases showed no improvement.

INTERPRETATION

Thoracic mobilization can be recommended in shoulder rehabilitation programs to improve forward shoulder posture to manage and prevent scapular malalignment in individuals with thoracic hyperkyphosis. We suggest that a high probability of improvement in forward shoulder posture can be expected when kyphosis is improved by >13.79%.

Does mobilisation of the thoracic spine using mechanical massage affect diaphragmatic excursion in individuals with thoracic hyperkyphosis?

BACKGROUND

Thoracic mobilisation improves thoracic hyperkyphosis and respiratory function. Diaphragmatic excursion is associated with respiratory function; however, limited studies have assessed the effect of thoracic mobilisation on diaphragmatic excursion.

OBJECTIVE

This study aimed to investigate the effects of thoracic mobilisation on diaphragmatic excursion and respiratory function in individuals with thoracic hyperkyphosis.

METHODS

Participants were recruited through Internet advertising and participated voluntarily. Nineteen healthy participants (age: 33.37 ± 6.56 years; height: 170.32 ± 7.92 cm; weight: 69.77 ± 14.70 kg) with thoracic hyperkyphosis underwent thoracic mobilisation for 8 weeks. Diaphragmatic excursion, thoracic kyphosis, and respiratory function were measured. Thoracic mobilisation was provided using a mechanical massage device.

RESULTS

Thoracic mobilisation for 8 weeks significantly improved diaphragmatic excursion during deep breathing (p= 0.015), forced vital capacity (p< 0.01), and thoracic hyperkyphosis (p< 0.01).

CONCLUSIONS

Thoracic mobilisation can be recommended in respiratory rehabilitation programs to increase diaphragmatic excursion and respiratory function for the management and prevention of respiratory dysfunction in individuals with thoracic hyperkyphosis.

Effects of abdominal drawing-in maneuver with or without prior iliopsoas stretching on gluteus maximus activity during prone hip extension

BACKGROUND

Prone hip extension (PHE) has been investigated to strengthen the hip joint and back extensor muscles. However, it has not been compared with various PHE exercises in individuals with iliopsoas shortness.

OBJECTIVE

This study compared pelvic compensation and hip and back extensor muscle activities in individuals with iliopsoas shortness during prone hip extension (PHE) using the abdominal drawing-in maneuver alone (PHEA) and after iliopsoas stretching (PHEAS).

METHODS

Twenty-five individuals with iliopsoas shortness were included in the study. Electromyography was used to investigate bilateral erector spinae (ES) and ipsilateral gluteus maximus (GM), biceps femoris (BF), and semitendinosus (ST) muscles during PHE, PHEA, and PHEAS. Pelvic anterior tilting and rotation angles were measured during each PHE exercise via electromagnetic motion tracking. A modified Thomas test was used to examine the hip extension angle before and after iliopsoas stretching. One-way repeated-measures analysis of variance was used to investigate differences in pelvic anterior tilting and rotation angle and in hip and back extensor muscle activities among PHE, PHEA, and PHEAS. The level of statistical significance was set at α= 0.01.

RESULTS

GM muscle activity was significantly greater with PHEAS, compared to PHE and PHEA (p< 0.01). Bilateral ES and ipsilateral BF and ST muscle activities were significantly reduced with PHEAS, compared to PHE and PHEA (p< 0.01). Anterior pelvic tilting and rotation angles were significantly reduced with PHEAS, compared to PHE and PHEA (p< 0.01).

CONCLUSIONS

PHEAS is recommended to selectively strengthen GM muscles with minimal BF and ST muscle activities and pelvic compensation in individuals with iliopsoas shortness. The abdominal drawing-in maneuver (ADIM) after iliopsoas stretching is more efficient than ADIM alone during PHE, especially in individuals with iliopsoas shortness.

Comparison of the Shoulder External Rotator Strength and Asymmetry Ratio Between Workers With and Without Shoulder Impingement Syndrome

ABSTRACT

Kim, J-H, Kwon, O-Y, Hwang, U-J, Jung, S-H, Ahn, S-H, and Kim, H-A. Comparison of shoulder external rotator strength and the asymmetry ratio between workers with and without shoulder impingement syndrome. J Strength Cond Res 35(12): 3364-3369, 2021-Shoulder impingement syndrome (SIS) is the most common shoulder problem causing shoulder pain. Several studies have indicated that shoulder external rotator muscles provide dynamic stability to the shoulder joint. However, the relationship of SIS to changes in shoulder external rotator muscle strength remains controversial. The purpose of the study was to compare the shoulder external rotator strength and asymmetry ratio between workers with SIS and the normal group in a side-lying position. Twelve male industrial workers with SIS and the normal group of 12 workers participated in this study. A pulling sensor measured shoulder external rotator muscle strength in a side-lying position with the shoulder at 0° and 90° of flexion. The asymmetry ratio was calculated by a specific formula using the shoulder external rotator muscle strength of the dominant side and the unaffected side. Two-way analysis of variance was used to determine between-group differences in shoulder external rotator muscle strength and the asymmetry ratio among the 2 positions. Subjects with SIS did not exhibit significant differences in shoulder external rotator muscle strength in the side-lying position with the shoulder at 0° and 90° of flexion relative to the normal group. However, subjects with SIS had a significantly increased asymmetry ratio of shoulder external rotation strength in the side-lying position with the shoulder at 90° of flexion compared with the normal group. In conclusion, workers with SIS had an asymmetry of shoulder external rotator strength in side-lying with the shoulder at 90° of flexion.

Comparison of scapular upward rotator muscle activities and activity ratios during three scapular upward rotator strengthening exercises

BACKGROUND: The focus of exercises for restoring the imbalance between scapular upward rotator muscles – upper trapezius (UT), serratus anterior (SA), and lower trapezius (LT) – commonly aims to increase SA and LT activities while not increasing UT activity. OBJECTIVES: The purpose of this study was to compare the activity of the UT, SA, and LT muscles during scapation and protraction exercises, which are two traditional exercises, and during a newly designed scapular upward rotation (SUR) exercise. METHODS: A total of 29 healthy young adult men performed all three exercises with maximum isometric contraction. The electromyographic activities of the UT, SA, and LT were recorded. RESULTS: UT demonstrated the highest activity during scapation. SA activity was the lowest during protraction. However, no difference was found in SA activity during the performance of scapation and SUR. The SA/UT ratio was the highest during scapation. CONCLUSIONS: SUR is a new exercise that can be performed at moderate intensity for shoulder rehabilitation to restore scapular upward rotator muscle imbalance.

Relationship Between Sexual Function and Pelvic Floor and Hip Muscle Strength in Women With Stress Urinary Incontinence

INTRODUCTION

The pelvic floor muscle (PFM) could affect female sexual functions. The hip muscles are morphologically and functionally linked to PFM and are important elements of female sexual attraction.

AIM

To determine the relationship between female sexual function and hip muscle strength and PFM functions in women with stress urinary incontinence (SUI).

METHODS

A total of 42 women with SUI were recruited in this study. Female sexual function was measured using the pelvic organ prolapse urinary incontinence sexual function questionnaire (PISQ). PFM functions were measured using a perineometer. Hip muscle strength was measured using a Smart KEMA tension sensor. The relationship between female sexual function and PFM function and hip muscle strength was assessed using Pearson correlation coefficients and multiple regression analyses with forward selection.

MAIN OUTCOME MEASURES

PISQ score, PFM functions (strength and endurance), and strength of hip extensor, abductor, and adductor were the main outcome measures.

RESULTS

For the behavioral/emotive domain in the PISQ, hip extensor strength (r = 0.452), PFM strength (r = 0.441), PFM endurance (r = 0.362), and hip adductor strength (r = 0.324) were significantly correlated and hip extensor strength emerged in multiple regression. For the physical domain in the PISQ, hip abductor strength (r = 0.417), PFM endurance (r = 0.356), hip adductor strength (r = 0.332), and PFM strength (r = 0.322) were significantly correlated and hip abductor strength entered in multiple regression. For partner-related domain in the PISQ, hip adductor (r = 0.386) and abductor strength (r = 0.314) were significantly correlated and hip adductor strength appeared in multiple regression. For the PISQ total score, hip extensor strength (r = 0.484), PFM endurance (r = 0.470), hip adductor strength (r = 0.424), hip abductor strength (r = 0.393), and PFM strength (r = 0.387) were significantly correlated and hip extensor strength and PFM endurance emerged in multiple regression.

CONCLUSION

The female sexual function could be related to not only PFM functions but also hip muscle strength in women with SUI. Hwang UJ, Lee MS, Jung SH, Ahn SH, Kwon OY. Relationship Between Sexual Function and Pelvic Floor and Hip Muscle Strength in Women With Stress Urinary Incontinence. Sex Med 2021;9:100325.

Comparison of pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between people with and without nonspecific low back pain

BACKGROUND

Faults in postural alignment and movement of the pelvis are associated with non-specific low back pain. However, limited studies have investigated the differences in pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between subjects with and without non-specific low back pain.

METHODS

Thirty-one subjects with non-specific low back pain and 31 subjects without non-specific low back pain were examined. Angular measures of the pelvic rotation angle in the transverse plane were obtained in the supine position and during active straight leg raise using a Smart KEMA measurement system.

FINDING

The pelvic rotation angle in the transverse plane during active straight leg raise was significantly greater in subjects with non-specific low back pain than in healthy subjects (p < 0.05). However, the pelvic rotation angle in the transverse plane in the supine position and asymmetry index of the pelvic rotation angle during active straight leg raise were not significantly different between subjects with and those without non-specific low back pain.

INTERPRETATION

This indicates that a greater pelvic rotation angle in the transverse plane during active straight leg raise could be contributing factors to the development of a non-specific low back pain related to lumbopelvic instability.

The association between genu recurvatum angle and the strength of the hip and knee muscles in standing workers

BACKGROUND

Increased genu recurvatum (GR) angle is a risk factor for knee injury. Identification of factors causing GR is important for the prevention and rehabilitation of GR. Few studies have investigated the association between muscle strength and GR.

OBJECTIVE

To examine the association between GR angle and hip and knee muscle strength in standing workersMETHODS:The participants in this study were 110 healthy volunteers (59 male, 51 female) who performed standing work in a theme park. The GR angle, muscle strength, and strength ratio of the lower extremities were measured to determine their associations with GR. The GR angle was measured using a Smart KEMA motion sensor, and muscle strength was assessed using a Smart KEMA strength sensor. Stepwise multiple regression models were used to investigate which muscles contributed most to the extent of the GR angle.

RESULTS

Stepwise multiple regression analysis showed that the decreased hip external rotator to hip internal rotator ratio, increased knee extensor to knee flexor ratio, and young age were associated with an increased GR angle.

CONCLUSIONS

Many factors are known to increase the GR angle. However, this study investigated the roles of only hip and knee muscle strength. The results suggest that muscle strength ratios are more important than the weakness of any muscle.

Comparison of the Strength and Electromyography of the Evertor Muscles With and Without Toe Flexion in Patients With Chronic Ankle Instability

BACKGROUND

Weakness of evertor strength is controversial in chronic ankle instability (CAI). Ankle evertor muscles are attached to the toe joints as well as to the metatarsal bone. Therefore, it is necessary to consider toe joint position for the measurement of evertor strength. The purpose of this study was to compare ankle evertor strength and muscle activity during eversion with and without toe flexion (TF) in individuals with CAI and individuals in a healthy group.

METHODS

Fifteen subjects with CAI and 15 healthy subjects participated in this study. Isometric ankle evertor strength and muscle activity of the peroneus longus (PL), peroneus brevis (PB), and extensor digitorum longus (EDL) were measured during eversion with and without TF.

RESULTS

The results indicated a significant interaction effect in evertor strength (P = .03) and no significant interaction effect on EMG of the PL (P = .08), PB (P = .12), and EDL (P = .28). However, measurements of muscle activity of the PL and PB between eversion with and without TF revealed a significant difference in the CAI group (P < .01) and no significant difference in the healthy group (PL: P = .07; PB: P = .13).

CONCLUSION

The results indicated that subjects with CAI had increased EDL compensation and reduced selective activation of the PL and PB during eversion.

CLINICAL RELEVANCE

Our findings suggest that clinicians should consider the activation of EDL when training the evertor of patients with CAI.

Effect of neuromuscular electrical stimulation training for abdominal muscles on change of muscle size, strength, endurance and lumbopelvic stability

BACKGROUND

Neuromuscular electrical stimulation (NMES) devices for abdominal muscles are being marketed to the general public to improve physical appearance. Abdominal muscles play an important role in lumbopelvic stability for optimizing performance. We investigated the effects of NMES training of abdominal muscles on muscle size, muscle strength, endurance, and lumbopelvic stability.

METHODS

Twenty-three subjects (12 females, 11 males) performed abdominal muscle NMES training for 8 weeks. Before and after NMES training, we measured muscle size (cross-sectional area [CSA] of the rectus abdominals [RA] and lateral abdominal wall [LAW]) by magnetic resonance imaging, muscle strength (trunk flexor and side bridge strength), endurance (trunk flexor and side bridge endurance time), and lumbopelvic stability (one-leg loading test).

RESULTS

There were significant increases between pre- and post-NMES training differences in the size (CSA of RA 21.7-25.4%, P<0.001; CSA of LAW 9.00-9.71%, P<0.001), strength (trunk flexor 14.9%, P<0.05; side bridge 33.7-53.6%, P<0.05), and endurance (trunk flexor 29.1%, P<0.05; side bridge 24.6-28.9%, P<0.05) of abdominal muscles and lumbopelvic stability (37.2-37.4%, P<0.05).

CONCLUSIONS

NMES training could be applied to increase muscle size and muscle performances of abdominal muscles in sports and fitness fields.

Which pelvic floor muscle functions are associated with improved subjective and objective symptoms after 8 weeks of surface electrical stimulation in women with stress urinary incontinence?

OBJECTIVE

Stress urinary incontinence (SUI) is defined as involuntary urine loss during effort, sneezing, or coughing. We investigated which pelvic floor muscle (PFM) functions (muscle strength, power, and endurance) are associated with improvement in subjective and objective symptoms after 8 weeks of surface electrical stimulation (SES) training. This study was performed to determine the effects of SES in the seated position on PFM functions and subjective and objective symptoms, and to identify predictors of improved subjective and objective symptoms after 8 weeks of SES training via secondary analysis of females with SUI.

STUDY DESIGN

The study was performed between August 2018 and December 2018. Patients with SUI were randomized into an SES group (n = 17) and a control group (n = 17). Both groups were assessed pre-intervention and after 8 weeks of intervention. The outcome measures were PFM functions (strength, power, and endurance) as measured via perineometry, the score on the urogenital distress inventory-6 (UDI-6), and the ultra-short perineal pad test result.

RESULTS

Significant differences in all PFM functions, the UDI-6 score, and the pad weight were evident both between the groups (SES vs. control group) and within the groups (pre-SES vs. post-SES). On regression of factors predicting relative changes in subjective and objective symptoms, the relative change in PFM power accounted for 15 and 13 % of the variance in the UDI-6 score (P < 0.05) and pad weight (P < 0.05), respectively.

CONCLUSIONS

SES in a seated position improved both subjective and objective symptoms in females with SUI. PFM power, the UDI-6 score, and the pad weight test result should be considered when developing intervention guidelines to improve the subjective and objective symptoms of females with SUI.

Pelvic Floor Muscle Parameters Affect Sexual Function After 8 Weeks of Transcutaneous Electrical Stimulation in Women with Stress Urinary Incontinence

INTRODUCTION

Stress urinary incontinence (SUI) is often associated with female sexual dysfunction. We investigated which pelvic floor muscle (PFM) parameters (strength, power, and endurance) are associated with improvement of sexual function after 8 weeks of transcutaneous electrical stimulation (TES) training.

AIM

This study was performed to determine the effects of TES in the seated position on PFM parameters and female sexual function and to identify correlation between improved PFM parameters and sexual function after 8 weeks of TES training in women with SUI.

METHODS

The present study was performed between August 2018 and November 2018 in women with SUI who were randomized into a TES group (n = 17) or a control group (n = 17). One subject in each of the TES and control groups ultimately withdrew during the intervention due to a lack of time. Both groups were measured at baseline and after 8 weeks of intervention.

MAIN OUTCOME MEASURE

As outcome measures, PFM parameters (strength, power, and endurance) and female sexual function were assessed using a perineometer and the Female Sexual Function Index (FSFI), respectively.

RESULTS

The final study population consisted of 32 women with SUI. There were significant differences in PFM strength, power, and endurance and FSFI domain scores (desire, arousal, orgasm, satisfaction, and total score) in both between-group analyses (TES vs control group) and within-group analyses (pre-TES vs post-TSE). Change in PFM endurance had the highest association with change in total FSFI total score (r = 0.437; P = .006), and change in PFM power had the highest association with change in FSFI satisfaction (r = 0.420; P = .008).

CONCLUSION

TES in a seated position showed a beneficial effect on sexual function in females with SUI. Consideration of PFM parameters associated with FSFI domain scores may be important when developing intervention guidelines to improve female sexual function. Hwang UJ, Lee MS, Jung SH, et al. Pelvic Floor Muscle Parameters Affect Sexual Function After 8 Weeks of Transcutaneous Electrical Stimulation in Women with Stress Urinary Incontinence. Sex Med 2019;7:505-513.

Comparison of maximal isometric forearm supination torque in two elbow positions between subjects with and without limited forearm supination range of motion

Study Design: Cross-sectional comparison. Introduction: Forearm supination range of motion is often limited by short or stiff pronators. Many studies have examined maximal isometric forearm supination torque (MIFST). However, there is little research comparing MIFST in two elbow positions between subjects with and without limited forearm supination range of motion (LSR). Purpose of the Study: The purpose of this study was to compare MIFST in two elbow positions (90º flexed elbow, extended elbow) between subjects with and without LSR. Methods: Thirteen right-handed subjects (seven men, six women) with LSR and 13 age- and gender-matched healthy controls participated in this study. The forearm supination range of motion and MIFST were measured using a Smart KEMA system. Two-way repeated-measures analysis of variance was used to compare MIFST in two elbow positions between subjects with and without LSR. Results: No significant difference between groups (p > .05) was found. However, there was an interaction effect between elbow position and group on MIFST (p < .05). Independent t-tests were used to confirm the simple effects. In the LSR group, the value of MIFST was significantly lower in the elbow-extended position than in the group without LSR (p < .05). Conclusions: These findings indicate that elbow position should be considered when assessing the strength or increasing the strength of the supinator muscle, especially in patients with LSR.

Immediate improvements of supination range of motion and strength following pronator teres muscle friction massage: a clinical trial comparing people with and without supination limited motion

OBJECTIVES

To investigate the effects of friction massage techniques on the pronator teres muscle on supination range of motion (ROM) and supinator strength in individuals with and without limited supination ROM.

METHODS

In total, 26 subjects (13 with limited supination ROM and 13 healthy subjects) volunteered to participate in this study. We used a customized wrist cuff. Supination ROM and supinator strength were measured with a 9-axis inertial motion sensor and load cell. The friction massage protocol was executed with the pronator teres muscle in a relaxed position. Then supination ROM and supinator strength were measured again.

RESULTS

There was no significant interaction effect on supination ROM, which was significantly greater in the limited supination and control groups. A post hoc t-test revealed that the limited supination group achieved a significantly increased post-test supination ROM (51.7 ± 7.8°) compared to the pre-test value (43.6 ± 5.2°). In addition, the control group achieved a significant increase in post-test supination ROM (67.7 ± 10.0°) compared to the pre-test value (61.4 ± 7.7°). There was no significant interaction effect on supinator strength. Supinator strength was significantly greater in the limited supination and control groups. A post hoc t-test revealed a significant difference in supinator strength between the pre- and post-test values in the limited supination group.

DISCUSSION

Friction massage helps restore a limited ROM of the forearm supination motion and immediately increases supinator muscle strength. This technique can be used as an intervention method to improve muscle strength in patients with limited supination ROM.

Predictors of pain intensity and Oswestry Disability Index in prolonged standing service workers with nonspecific chronic low back pain subclassified as active extension pattern

BACKGROUND

Because patients with nonspecific chronic low back pain (NSCLBP) are heterogeneous, subgrouping patients with NSCLBP might clarify the research findings. NSCLBP in the direction of extension movement, namely active extension pattern (AEP), is common during prolonged standing.

OBJECTIVE

Predictors of pain intensity and dysfunction were determined in prolonged standing service workers (PSSWs) with NSCLBP subclassified as AEP in the motor impairment subgroup.

METHODS

Variables were measured using questionnaires including a visual analog scale (VAS), the Oswestry Disability Index (ODI), Borg Rating of Perceived Exertion (RPE) Scale, and Korean Occupational Stress Scale (KOSS). Postural assessment was performed by measuring pelvic anterior tilting angle (PATA). The smart KEMA measurement system was used to evaluate hip flexion, hip extension (HE), and knee flexion range of motion (ROM), as well as hip extensor strength, hip abductor strength (HArS), hip external rotator strength (HERrS), hip internal rotator strength, knee extensor strength, and knee flexor strength, and lumbopelvic stability (LS) in 78 PSSWs with NSCLBP subclassified as AEP.

RESULTS

In prediction models, HArS, LS, PATA, KOSS and HE ROM accounted for 40.1% of the variance in the VAS (p < 0.05); predictors of dysfunction included the HERrS and age, which accounted for 11.9% of the variance in the ODI (p < 0.05) in multiple regression models when using a stepwise selection procedure.

CONCLUSIONS

The present results indicate that HArS and HERrS, LS, PATA, KOSS, HE ROM and age should be considered for evaluating and predicting NSCLBP subclassified as AEP in PSSWs, and when designing interventions.

Effects of 4-week self-cross body stretching with scapular stabilization on shoulder motions and horizontal adductor strength in subjects with limited shoulder horizontal adduction: cross body stretching with stabilization

BACKGROUND

Posterior shoulder tightness is related to shoulder conditions such as shoulder impingement and limited shoulder horizontal adduction (SHA). The purpose of this study was to compare the effects of self-cross body stretching (CBS) with and without scapular stabilization (SS) on SHA and shoulder internal rotation (SIR) range of motion (ROM) and shoulder horizontal adductor strength (SHAS) in subjects with limited SHA.

METHODS

Twenty-six subjects (14 males, 12 females) with limited SHA was participated in this study. The SS group and without stabilization (WS) group were assigned randomly. The SS group performed self-CBS with SS by applying belt just under the subject's axilla. The subjects were asked to perform self-CBS 4 times a week for 4 weeks. SHA and SIR RM were measured by Clinometer smartphone application, and SHAS by hand-held dynamometer before and after 4-week self-CBS.

RESULTS

2 × 2 mixed analysis of variance (ANOVA) was used to identify the significance. If there was an interaction effect, t-test was used to confirm the simple effect. There was a significant interaction in SHA ROM and SHAS. The post-test value of SHA ROM was significantly greater in SS group than WS group (P<0.0125). In SHAS, there was no significant difference between groups (P>0.0125).

CONCLUSIONS

SS during self-CBS could enhance to improve SHA, SIR ROM, and SHAS in individuals with limited SHA.

Effect of applying consistent pressure to the stationary and the moving arm on measurement reliability of glenohumeral internal rotation range of motion

OBJECTIVES

The aim of this study was to determine the inter-rater reliability of glenohumeral internal rotation (GIR) range of motion (ROM) and pressure measurements among four measurement methods: (1) Manual stabilization of the humeral head and coracoid process (MSHC) without applying consistent pressure (ACP) to both the stationary and the moving arms (BSaMA); (2) MSHC with ACP to the moving arm; (3) MSHC with ACP to the stationary arm; and (4) MSHC with ACP to BSaMA.

DESIGN

Test-retest analyses.

PARTICIPANTS

39 subjects with GIR deficit.

MAIN OUTCOME MEASURES

GIR ROM and pressure were measured on the stationary or moving arm by four examiners using the Clinometer application and a pressure biofeedback unit.

RESULTS

GIR ROM measurement with MSHC and ACP to the moving arm resulted in the lowest intra-class correlation coefficient (ICC = .43); the ICC for MSHC without ACP to BSaMA was .54; that for MSHC with ACP to the stationary arm was .77; and that for MSHC with ACP to BSaMA was highest, at .81.

CONCLUSION

MSHC with ACP to both arms leads to reliable GIR ROM measurement in a clinical setting.

Comparison of shoulder strength in males with and without myofascial trigger points in the upper trapezius

BACKGROUND

This study was conducted in order to compare the strength of scapular elevator and shoulder abductor with and without restricted scapular elevation between male subjects with and without myofascial trigger points in the upper trapezius.

METHODS

In total, 15 male subjects with myofascial trigger points, and 15age- and weight-matched male subjects without myofascial trigger points in the upper trapezius. Each subject was measured in the strength of maximum isometric scapular elevation and shoulder abduction with and without restricted scapular elevation. Maximum isometric contractions were measured using the Smart KEMA strength measurement system. Independent t-tests were used to compare shoulder strength values between the myofascial trigger points and non- myofascial trigger points groups.

FINDING

The results showed that shoulder abductor strength in the group with myofascial trigger points (5.64kgf) was significantly lower than in the group without myofascial trigger points (11.96kgf) when scapular elevation was restricted (p<0.05). However, there was no significant difference in the strength of the scapular elevator or shoulder abductor between groups (p>0.05).

INTERPRETATION

These findings suggest that decreased strength in the shoulder abductor with restricted scapular elevation should be considered in evaluating and treating individuals with myofascial trigger points of the upper trapezius.

Predictors of upper trapezius pain with myofascial trigger points in food service workers: The STROBE study

Shoulder pain occurs commonly in food service workers (FSWs) who repetitively perform motions of the upper limbs. Myofascial trigger points (MTrPs) on the upper trapezius (UT) are among the most common musculoskeletal shoulder pain syndromes. This study determined the psychological, posture, mobility, and strength factors associated with pain severity in FSWs with UT pain due to MTrPs.In this cross-sectional study, we measured 17 variables in 163 FSWs with UT pain due to MTrPs: a visual analog scale (VAS) pain score, age, sex, Borg rating of perceived exertion (BRPE) scale, beck depression inventory, forward head posture angle, rounded shoulder angle (RSA), shoulder slope angle, scapular downward rotation ratio, cervical lateral-bending side difference angle, cervical rotation side difference angle, glenohumeral internal rotation angle, shoulder horizontal adduction angle, serratus anterior (SA) strength, lower trapezius (LT) strength, bicep strength, and glenohumeral external rotator strength, in 163 FSWs with UT pain due to MTrPs.The model for factors influencing UT pain with MTrPs included SA strength, age, BRPE, LT strength, and RSA as predictor variables that accounted for 68.7% of the variance in VAS (P < .001) in multiple regression models with a stepwise selection procedure. The following were independent variables influencing the VAS in the order of standardized coefficients: SA strength (β = -0.380), age (β = 0.287), BRPE (β = 0.239), LT strength (β = -0.195), and RSA (β = 0.125).SA strength, age, BRPE, LT strength, and RSA variables should be considered when evaluating and intervening in UT pain with MTrPs in FSWs.

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 coefficient_2,3=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.