The purpose of this study is to compare recreationally physically active females and males with regard to spine, pelvis and lower limb joints peak angles in each plane of motion during a single leg squat (SLS). The second aim is to investigate the relationship between kinematics and SLS depth in females and males. Fifty-eight healthy, young adults performed 5 repetitions of a single right leg squat to maximal depth while keeping their balance. Kinematic data were obtained using an optical motion capture system. At the hip, greater adduction and greater internal rotation were observed in females than in males. Females had more extended spines and less outward bended knees throughout the SLS than did men. In males, squat depth was significantly, positively correlated with the maximal angle of the ankle (r = 0.60, p < 0.001), the knee (r = 0.87, p < 0.001), the hip (r = 0.73, p < 0.001) and the pelvis (r = 0.40, p = 0.02) in the sagittal plane. A positive significant correlation was found between SLS depth and maximal angle of the knee (r = 0.88, p < 0.001) and the ankle (r = 0.53, p = 0.01) in the sagittal plane in females. Males and females used different motor strategies at all levels of the kinematic chain during SLS.

The presented study aimed to analyze and compare the electromyographic patterns of masticatory muscles in subjects with active myofascial trigger points (MTrPs) within upper trapezius, patients with temporomandibular disorders (TMDs) and healthy adults. Based on the diagnostic criteria of MTrPs according to Travell & Simons and the Research Diagnostic Criteria for Temporomandibular Disorders, 167 people were qualified for the study. Subjects were divided into 3 groups: with active MTrPs in the upper trapezius, with diagnosed temporomandibular disorders (TMDs) and healthy adults. Measurements of the bioelectric activity of the temporalis anterior (TA) and masseter muscle (MM) were carried out using the BioEMG III ™. Based on statistical analysis, significantly lower values of TA resting activity were observed among controls in comparison to MTrPs (1.49 μV vs. 2.81 μV, p = 0.00) and TMDs (1.49 μV vs. 2.97 μV, p = 0.01). The POC index values at rest differed significantly between MTrPs and TMDs (86.61% vs. 105%, p = 0.04). Controls presented different electromyographic patterns within AcI in comparison to both MTrPs (4.90 vs. −15.51, p = 0.00) and TMDs (4.90 vs. −16.49, p = 0.00). During clenching, the difference between MTrPs and TMDs was observed within MVC TA (91.82% vs. 116.98%, p = 0.02). TMDs showed differences within AcI in comparison to both MTrPs group (−42.52 vs. 20.42, p = 0.01) and controls (−42.52 vs. 3.07, p = 0.00). During maximum mouth opening, differences between MTrPs and TMDs were observed within the bioelectric activity of masseter muscle (16.45 μV vs. 10.73 μV, p = 0.01), AsI MM (0.67 vs. 11.12, p = 0.04) and AcI (13.04 vs. −3.89, p = 0.01). Both the presence of MTrPs in the upper trapezius and TMDs are related to changes in electromyographic patterns of masticatory muscles.

Introduction and objective: Low back pain (LBP) is a problem which causes human suffering and entails costs for treatment. Chronic LBP is considered a civilization diseases in developed countries and one of the major public health problem worldwide. Squatting is a part of such daily...

Masticatory muscle activity during teeth clenching is associated with changes in many physiological parameters throughout the body. Clenching can improve muscle activity, force production, rate of force development, and joint fixation. Hence, teeth clenching and masticatory muscle activity can be important in competitive sports activities. Sport climbing is becoming increasingly popular and will be included for the first time in the Summer Olympic Games, Tokyo, 2020. However, masticatory muscle activity in sport climbers has not yet been studied. The aim of the presented study is to compare the bioelectrical activity of the masticatory muscles in sport climbers and non-climbers in order to determine the relationship between these muscles and climbing activity. 44 subjects without masticatory system disorders (16 women and 28 men, average age 26.3) were divided into two groups of 22 sport climbers (8 women, 14 men, climbing experience >4 years), while 22 people (8 women, 14 men, with no regular sports activity) were assigned to the control group. Electromyographic examination of temporalis anterior (TA) and masseter muscle (MM) was evaluated in three conditions: during resting mandibular position, during maximum intercuspation clenching, and during maximum voluntary clenching with cotton rolls between teeth. For statistical analysis, the W Shapiro-Wilk test and the Mann-Whitney U test were used. Sport climbers showed significantly higher bioelectrical activities of MM during maximum intercuspation clenching (238.45 μV vs. 83.87 μV, p = 0.002), and during maximum voluntary clenching with cotton rolls between teeth (300.01 μV vs. 101.38 μV, p = 0.001) compared to controls. The differences between groups in relation to the resting bioelectrical activity of the MM muscles, and TA muscles in all conditions were not statistically significant (p > 0.05). Higher bioelectrical activity of masseter muscles during clenching in climbers can be associated with this sports activity. However, the mechanism remains unknown and requires future research.

Introduction: Studies suggest that temporomandibular disorders (TMD) are a complex disorder with many causes consistent with the biopsychosocial disease model. One of the important areas of TMD etiology are psychological factors, including stress, but its role in the mechanism of TMD formation is ambiguous. Aim: The aim of this literature review was to summarize the latest study about the impact of stress in relation to temporomandibular joint disorders. Material and methods: Articles from PubMed and PEDro online databases were identified using the keywords ‘stress,’ ‘distress,’ ‘TMD.’ The review included works published in the period from October 1, 2015 to March 6, 2020. Finally, 10 articles were qualified for the review. Results and discussion: The most frequently used research tool was the questionnaire. Other methods used to evaluate a level of stress in TMD patients were measurement of cortisol level and surface electromyography of masticatory muscles. Conclusions: Stress is one of the psychological factors involved in TMD pathophysiology. Increased levels of stress in patients with TMD are associated with elevated levels of cortisol, hyperactivity of the HPA axis and increased bioelectric activity of the masticatory muscles. There is a need to extend research on the effects of stress on TMD by more objective methods.

Background: The aim of this study was to determine the influence of moderate depression determined based on Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMDs) Axis II on the bioelectrical resting activity of temporal muscles and masseter muscles. Methods: The research participants were 68 healthy adult women. Of these, 46 people h (mean age: 22 ± 1 year) who had no temporomandibular disorders were selected for the research. They were divided based on results from RDC/TMDs (Axis II: scale’s measurement) into the study group with a moderate level of depression (23 people), rest of participants without symptoms of depression were classified to control group (23 people). The resting activity of temporal muscles and masseter muscles was examined by using BioEMGIII electromyograph. Two statistical analyses were used: Shapiro–Wilk test and Mann–Whitney U test. Results: Despite higher mean tensions of temporal muscles and masseter muscles in the group with depression, results findings were not statistically significant (p > 0.05). Conclusions: Moderate depression determined based on the RDC/TMDs II axis questionnaire is not related to the resting activity of selected masticatory muscles. Further research should be continued on a larger group of respondents in order to establish the relationship between psychological factors and bioelectrical parameters of the masticatory muscles.