Search Results (57)

Background/Objectives: Bruxism has been associated with dysregulation of the autonomic nervous system (ANS). Visceral manual therapy (VMT) has shown beneficial effects on the vagal tone and modulation of ANS activity. This study aimed to evaluate the immediate and short-term effects of VMT in individuals with clinically based bruxism. Methods: A single-blind randomized controlled trial was conducted including 24 individuals with clinically based bruxism. Participants received two sessions of either VMT or a sham placebo technique. Outcome measures included heart rate variability (HRV), both normal-to-normal intervals (HRV-SDNN), and the root mean square of successive normal-to-normal intervals (HRV-RMSSD), as well as muscle tone and stiffness and pressure pain thresholds (PPTs). Measurements were made at T1 (baseline), T2 (post-first intervention), T3 (pre-second intervention), T4 (post-second intervention), and T5 (4-week follow-up). Results: A significant time*group interaction was observed for HRV-SDNN (p = 0.04, η² = 0.12). No significant changes were found for muscle tone or stiffness. PPTs significantly increased at C4 after the second session (p = 0.049, η² = 0.16) and at the left temporalis muscle after the first session (p = 0.01, η² = 0.07). Conclusions: The findings suggest that two sessions of VMT may lead to significant improvements in HRV-SDNN compared to the placebo, suggesting a modulatory effect on autonomic function. No consistent changes were observed for the viscoelastic properties of the masticatory muscles. Isolated improvements in pressure pain sensitivity were found at C4 and the left temporalis muscle. Further research with larger sample sizes and long-term follow-up is needed to determine the clinical relevance of VMT in the management of signs and symptoms in individuals with bruxism. Full article

Background: Myofascial trigger points (MTrPs) are hyperirritable spots within taut bands of skeletal muscle fibers, often developing in overloaded muscles. Ischemic compression (IC) is a frequently used therapeutic technique for MTrP treatment. Material and Methods: Seventy-nine participants with MTrPs in the upper trapezius muscle were included. Three IC protocols were used. In group 1, the compression force was increased once; in group 2, twice; and in group 3, three times—each time up to the pain threshold, then held constant until the pain subsided. Evaluations included pressure pain threshold (PPT), pressure pain perception (PPP), and myotonometric measurements. Results: PPT values increased significantly in group 2 (p = 0.009) and group 3 (p = 0.009), while PPP values decreased significantly in both groups (group 2: p = 0.016; group 3: p = 0.041) post-intervention. Group 1 showed a significant reduction in muscle tone (p < 0.001), and group 2 in muscle stiffness (p = 0.036). Muscle elasticity significantly improved in all groups: group 1 (p = 0.022), group 2 (p = 0.001), and group 3 (p = 0.042). Conclusions: IC applied with a constant force at the individual’s pain perception threshold effectively elevates the pain threshold and enhances the biomechanical parameters of muscle fibers in the trigger point area. Full article

Background: Pain manifestations as well as increased muscle tone and stiffness noted in the course of delayed-onset muscle soreness (DOMS) are reflected in altered values of the biomechanical and visco-elastic parameters of muscles. This study aimed to compare the effects of soft tissue mobilization with foam rolling and percussive massage on symptoms of DOMS induced by a standardized muscle fatigue protocol. Methods: Healthy volunteers (n = 60) were divided into three groups: FR group—foam rolling (n = 20), PM group—percussive massage (n = 20) and CON group—control/passive rest (n = 20). The fatigue protocol for the gastrocnemius muscle was carried out for development of DOMS in subsequent days. Therapeutic procedures were applied to participants for 3 consecutive days. The results of therapy were assessed by means of myotonometry, performed five times (before, three times during the treatment procedure, and after the end of the procedure). Results: Foam rolling significantly reduced the onset and duration of increased muscle tone (p = 0.006) and stiffness (p < 0.001), unlike percussive massage. The control group exhibited higher tone and stiffness after 48 h, at the peak of DOMS-related pain symptoms. Only foam rolling improved elasticity (decrement, p < 0.001), while visco-elastic properties (relaxation, creep) varied inversely with tone and stiffness. Foam rolling led to significantly lower stiffness (day 2) and reduced decrement and relaxation (day 4) compared to the control. Neither therapy was more effective than passive rest for pain relief during the observation period. Conclusions: Foam rolling and percussive massage accelerate recovery of muscle tone, stiffness, and elasticity after DOMS as compared to passive rest but offer no added benefit for pain relief. Full article

Background: This study aimed to investigate the acute changes in muscle and tendon viscoelastic properties in response to a progressive treadmill VO₂max test among professional male soccer players. Methods: Bilateral assessments at five sites—the Achilles tendon (AT), biceps femoris, semitendinosus, rectus femoris (RF), and sternocleidomastoid (SCM)—measured tone (oscillation frequency), dynamic stiffness, logarithmic decrement (elasticity), stress relaxation time, and creep. Each site was probed five times and values averaged. Repeated-measures ANOVA (Time × Side) with Bonferroni correction tested pre- to post-exercise changes; Pearson’s r examined associations with VO₂max. Results: Significant Time effects (all p < 0.05) were observed for RF frequency (η_p² = 0.226), RF creep (η_p² = 0.144), AT stiffness (η_p² ≈ 0.035), AT frequency (η_p² = 0.035), and SCM frequency (η_p² = 0.037). Post-exercise, right AT stiffness fell by 65 ± 14 N/m (p = 0.015), while left AT stiffness rose by 22 ± 9 N/m (p = 0.015). RF stiffness decreased by 28 ± 6 N/m (p < 0.001) and tone by 1.2 ± 0.3 Hz (p < 0.001), with creep (+0.08 ± 0.02; p < 0.001) and relaxation time (+1.5 ± 0.7 ms; p < 0.001) increasing. SCM tone declined by 0.8 ± 0.4 Hz (p = 0.010). Baseline RF properties—frequency (r = −0.597), stiffness (r = −0.59), relaxation time (r = 0.53), and creep (r = 0.48)—correlated moderately with VO₂max (all p < 0.05). Conclusions: These findings suggest that viscoelastic adaptations to exhaustive aerobic exercise are tissue- and side-specific, and that rectus femoris viscoelastic properties may serve as potential indicators of endurance readiness. Full article

Spasticity, characterized by elevated muscle tone, is commonly managed with botulinum toxin type A (BTX-A). However, BTX-A can paradoxically increase passive muscle forces, narrow muscles’ length range of force exertion (l_range), and elevate extracellular matrix (ECM) stiffness. C3 transferase, known to inhibit myofibroblast and fascial tissue contractility, may counteract ECM stiffening. This study investigated whether combining BTX-A with C3 transferase reduces active forces without altering passive forces or l_range. Additionally, we examined the isolated effects of C3 transferase on muscle levels. Male Wistar rats received injections into the tibialis anterior (TA): Control (n = 7, saline) and C3 + BTX-A (n = 7, 2.5 µg C3 + 0.1U BTX-A). TA forces were measured one month post-injection, and isolated C3 transferase effects were assessed in separate groups (Control and C3, n = 6 each). Active forces were 43.5% lower in the C3 + BTX-A group compared to the Control group. No differences between groups in passive forces (p = 0.33) or l_range (p = 0.19) were observed. C3 transferase alone had no significant effect on relative muscle mass (p = 0.298) or collagen content (p = 0.093). Supplementing BTX-A with C3 transferase eliminates BTX-A’s adverse effects at the muscle level. C3 transferase alone causes no atrophy or collagen increase, which are key factors in BTX-A-induced ECM stiffening. This novel neurodenervant formula shows promise for advancing spasticity management. Full article

Background/Objectives: The adverse effects of low gravity on human physiology are well documented; however, much of the literature is directed at changes which occur in microgravity (µg: weightlessness) with relatively less documented on changes in hypogravity (<1 g; >µg: gravity less than Earth’s but more than microgravity). Somatosensation and neuromuscular control may be of particular importance for astronauts as they prepare for future missions to walk on the Moon. This study aimed to explore the effect of reduced weight bearing (to simulate conditions of hypogravity) on ankle somatosensation, lower-limb muscle activity, tone, and stiffness, compared to full weight bearing. Methods: Participants completed an ankle somatosensory acuity task (active movement extent discrimination assessment [AMEDA]) in two body positions: (1) upright standing (1 g), and (2) in a head-elevated supine, semi-weight bearing (0.16 g) position using a custom-built inclined “wedge bed”. The second position induced ~16% body weight on to the plantar aspect of the feet, simulating that of lunar gravity. We compared the AMEDA scores between the two positions. Lower-limb muscle activity was recorded via surface EMG throughout the AMEDA task for both positions. The ankle AMEDA has five depths of ankle inversion. We compared muscle activity between the body positions, and muscle activity between inversion depths “1” and “5” (within each position). Lower-limb muscle tone and muscle stiffness were assessed at rest in both body positions using the MyotonPRO. Results: Fifty-five participants between the ages of 18 and 65 (28 females, 27 males; mean age of 40 years) completed the study. The AMEDA scores, muscle tone and stiffness were reduced when the participants were on the lunar wedge bed, compared to upright standing (p = 0.002; p < 0.001; p < 0.001). Some lower-limb muscles exhibited less activity in the lunar wedge-bed position compared to upright standing (tibialis anterior, peroneus longus, vastus lateralis, rectus femoris; p < 0.05) but others were unchanged (gastrocnemius, vastus medialis; p > 0.05). Muscle activity was unchanged between the AMEDA depths (p = 0.188). Conclusions: The results provide insight into how the somatosensory and neuromuscular systems respond to reduced weight bearing and potentially lunar gravity conditions, thereby informing how to target interventions for future missions. Full article

Objective: To analyse the relationship between traditional stiffness and muscle antagonist coactivation in both stroke and healthy participants, using linear and non-linear measures of coactivation and COP during standing, stand-to-sit, and gait initiation. Methods: Participants were evaluated through a cross-sectional design. Electromyography, isokinetic dynamometer, and force plate were used to calculate coactivation, intrinsic and functional stiffness, and COP displacement, with both linear and non-linear metrics. Spearman’s correlations and Mann–Whitney tests were applied (p < 0.05). Results: Post-stroke participants showed higher contralesional intrinsic stiffness (p = 0.041) and higher functional stiffness (p = 0.047). Coactivation was higher on the ipsilesional side during standing (p = 0.012) and reduced on the contralesional side during standing and transitions (p < 0.01). Moderate correlations were found between intrinsic and functional stiffness (p = 0.030) and between coactivation and intrinsic stiffness (standing and stand-to-sit: p = 0.048) and functional stiffness (gait initiation: p = 0.045). COP displacement was reduced in post-stroke participants during standing (p < 0.001) and increased during gait initiation (p = 0.001). Post-stroke participants exhibited increased gastrocnemius/tibialis anterior coactivation during gait initiation (p = 0.038) and higher entropy and stability across tasks (p < 0.001). Conclusion: Post-stroke participants showed higher contralesional intrinsic and functional stiffness, reduced coactivation in static tasks, and increased coactivation in dynamic tasks. COP and coactivation analyses revealed impaired stability and random control, highlighting the importance of multidimensional evaluations of postural tone. Full article

Objectives: This study investigated the mechanical properties (tone, stiffness, and elasticity) of the biceps brachii (BB) muscle in the acute phase of different burn types. Methods: A total of 30 individuals (18–63 years) participated and were divided into three groups: flame, electrical, and scald burns. Myotonometric measurements assessed BB muscle tone, stiffness, and elasticity at admission (week 1) and at weeks 2 and 3. Results: When comparing the three time points, BB tone and stiffness significantly decreased by week 3 (p < 0.05), while elasticity remained unchanged (p > 0.05). Across burn types, BB tone, stiffness, and elasticity were similar at all three time points (p > 0.05). In the acute phase, BB tone and stiffness decreased by week 3, but elasticity showed no change. Conclusions: Different burn types exhibited similar BB mechanical properties over time. However, burn types may influence muscle tone and stiffness differently during acute recovery. Further studies with larger populations are needed to compare treatments across burn types and assess long-term mechanical property changes. Full article

Background: Adequate hamstring flexibility is crucial for musculoskeletal health as increased muscle tone can lead to stretch-type injuries, muscle weakness, dysfunctional neuromuscular control, postural changes, and lower back pain. The aim was to compare the effectiveness of a program based on Electrical Muscle Elongation (EME), Proprioceptive Neuromuscular Facilitation (PNF), and no intervention in improving flexibility and viscoelastic properties of hamstring and quadriceps muscles in active young adults with functional hamstring disorder (type 2B according to the Munich Consensus). Methods: Sixty-five participants (45 male, 20 female) were randomly assigned to three groups: the EME group (n = 21) received a simultaneous combination of interferential current and stretching, the PNF group (n = 22) underwent active stretching, and the Control group (n = 22) received no intervention. Hamstring and quadricep flexibility and muscle stiffness were measured in both limbs at baseline, post-intervention, and at the 4-week follow-up. Results: The EME group showed significant improvements in hamstring flexibility in the left limb compared to the Control group and in some myotonometric variables of the quadriceps muscle compared to the PNF and Control groups (p < 0.05). Within-groups differences indicated higher improvements in the EME group. Conclusions: This study suggests that EME may offer greater benefits than PNF stretching in young adults with functional hamstring disorder. Full article

Background/Objectives: The present study aimed to investigate the relationship between forward head posture (FHP) and the mechanical properties of muscles as well as the influence of FHP on them. Methods: To define participants with FHP, craniovertebral angle (CVA) was measured. All participants were divided into two groups in accordance with their CVA: the experimental group (FHP) consisting of participants with a CVA below 50°, and the control group (CON) consisting of participants with a CVA above 50°. The tone, stiffness, and elasticity of the upper trapezius muscle (UT), the middle trapezius muscle (MT), the lower trapezius muscle (LT), the sternocleidomastoid muscle (SCM), the splenius capitis muscle (SC), the pectoralis major muscle (PM), and the serratus anterior muscle (SA) were measured using MyotonPro (Myoton AS, Tallinn, Estonia). Results: Both tone and stiffness in the UT were statistically significant (p < 0.05). In addition, stiffness in the LT was statistically significant (p < 0.05). No significant differences were found in tone, stiffness, and elasticity of the MT, SCM, SC, PM, and SA muscles (p > 0.05). A significant correlation was found between FHP and both tone and stiffness in the UT (r = −0.731, p = 0.000; r = −0.749, p = 0.000, respectively). No significant correlation was found between FHP and tone, stiffness, and elasticity of the MT, LT, SCM, SC, PM, and SA muscles. Conclusions: Since the UT was the muscle in which changes in mechanical properties were first induced by FHP, an approach targeting UT is necessary as a priority when treating patients with FHP. Full article

Background: Running, a fundamental motor skill, evolves with experience, significantly influencing coordination and thoracic mobility. Our study aims to investigate whether prolonged engagement in running could result in distinct variations in thoracolumbar mobility and kinematic efficiency among individuals with varying levels of running experience. Methods: This study examined thoracic mobility among sedentary individuals and runners who have been running for the last six months and the last two years. Measurements included latissimus dorsi (LD) muscle tone, elasticity, stiffness, trunk flexibility and range of motion (ROM), lumbar extensor shortness, thoracolumbar fascia (TLF) length, and the modified Schober test. Results: LD tone was lower in six-month runners, while sedentary individuals had the greatest LD elasticity and stiffness. The modified Schober test results indicated that the six-month runners scored the highest. Two-year runners had significantly greater dominant-side lateral flexion than sedentary individuals and six-month runners. TLF length was highest in running for two-year runners. Two-year runners exhibited the greatest dominant-side lateral flexion, while six-month runners showed more flexion and two-year runners more extension. Conclusions: Prolonged running experience may enhance thoracolumbar mobility and muscle tone. Furthermore, the observed stiffness and reduced elasticity in sedentary individuals highlight the detrimental effects of inactivity on spinal and muscular health. Full article

Background/Objectives: Arterial stiffness, a critical predictor of cardiovascular events, varies regionally across peripheral, central, and systemic arteries, necessitating targeted exercise interventions for young men. However, research on the effects of exercise on arterial stiffness in these regions among young men remains limited. This review aims to (i) examine the effects of exercise on arterial stiffness in young men across these regions, and (ii) investigate the underlying mechanisms involved. Methods: Database searches on PubMed, ScienceDirect, Web of Science, and Scopus were conducted up to July 2024. The keywords were: exercise, men/male, and arterial stiffness. Inclusion criteria were studies involving young men, supervised exercise, and arterial stiffness measures. Thirty-five papers were categorized into groups based on peripheral, central and systemic arterial stiffness. Results: Peripheral arterial stiffness: continuous aerobic cycling (light to high intensity), interval aerobic cycling (moderate to high intensity), and 30-s stretching exercises demonstrated positive effects, likely due to short-term changes in sympathetic nervous system activity, nitric oxide availability, and vascular tone. Central arterial stiffness: chronic high-intensity continuous and interval aerobic cycling exercises promoted vascular remodeling, including elastin preservation and collagen regulation. For systemic arterial stiffness, continuous and interval aerobic cycling and light-intensity squats with whole-body vibration exercises improve endothelial function, smooth muscle relaxation, and vascular remodeling. Conclusions: Tailored exercise intervention can effectively reduce arterial stiffness across peripheral, central and systemic regions in young men. Improvements in peripheral stiffness are linked to short-term metabolic shifts, central stiffness responds to long-term remodeling, while systemic arterial stiffness involves both short- and long-term metabolic adaptations. Full article

Background: The prolonged use of smartphones may lead to cervical posture deformities and other associated issues. Among these conditions, cervical extension type is one of the most commonly observed, characterized by increased cervical lordosis, forward head posture, and thoracic kyphosis. These biomechanical changes may lead to neck pain, a restricted range of motion (ROM), and heightened cervical muscle tone. The purpose of this study was to evaluate the impact of combining cervical stabilization exercises with either scapular stabilization or thoracic exercises on the mechanical properties of cervical muscles, the pressure pain threshold (PPT), and the ROM in individuals with cervical extension type. Methods: This study included 32 subjects with cervical extension type who were randomly divided into two groups: 16 subjects were placed in either the cervical and scapular stabilization exercises group (CSG) or the cervical stabilization with thoracic exercises group (CTG). After four weeks of exercise intervention, the following assessments were conducted: measurement of muscle tone, stiffness, and elasticity of the sternocleidomastoid (SCM) and upper trapezius (UT) muscles using Myoton PRO; evaluation of the PPT of the SCM and UT muscles using a pressure pain threshold meter; and assessment of cervical ROM (extension, flexion, and rotation) using motion analysis equipment. Results: Both groups showed significant differences in muscle tone, stiffness, elasticity, PPT, and cervical ROM (p < 0.05). The PPT of the UT muscle was significantly improved in the CSG compared to the CTG (p < 0.05). Conclusions: There were significant improvements in muscle tone, stiffness, elasticity, pain, and cervical ROM after exercise intervention in both groups of subjects with cervical extension. Cervical stabilization exercises, along with scapular stabilization, have better effects on improving UT muscle pain. Full article

Background: Various types of dentures are applied in the treatment of missing teeth. The research carried out so far has proven that both the absence of teeth and the replacement of missing teeth with dentures affect the functional condition of masseter muscles. The purpose is, thus, to find out how the tone, elasticity, and stiffness of masseter muscles change after prosthetic treatment. Material and methods: The material for the study consisted of 137 individuals, who were divided into group 1, with dentures (n = 87) and undergoing prosthetic treatment, and group 2, without dentures (n = 50) with teeth preserved, and not undergoing prosthetic treatment. Additionally, group 1 was divided into subgroups, in accordance with the type of prosthetic treatment applied: group 1a—removable complete dentures (n = 14), group 1b—removable partial dentures (n = 48), group 1c—fixed partial dentures (n = 22), group 1d—fixed complete dentures (n = 3). The biomechanical properties of masseter muscles, namely: tone, stiffness, and elasticity were assessed by means of myotonometry. The measurements were taken under muscle relaxation and under maximum muscle contraction. Results: The values of the parameters of tone, stiffness, and elasticity were higher in group 2, without dentures, in comparison with group 1, with dentures, yet they did not differ with statistical significance. The type of prosthesis used affected the results obtained. Masseter muscles demonstrated the best biomechanical parameters in the case of applying fixed partial dentures. Conclusions: Prosthetic replacement of missing teeth contributes to maintaining the good condition of masseter muscles, which has been confirmed by the results of myotonometric measurements taken. Full article

Background/Objectives: Cesarean birth (CB) is linked to nonspecific low back pain (NSLBP). Different properties of the muscular tissue, including contractile, biomechanical, and viscous properties, may reflect its physiological or pathological condition. This study aimed to measure these properties of lumbar paravertebral muscles (LPVMs) and their relationship with post-CB mothers with moderate-severity NSLBP and match their measurements to those of the controls. Methods: Sixty women were included in this case–control research. They were divided into two equal groups: Group (A) representing cases, consisted of 30 females who experienced CB and complained of moderate-severity NSLBP, and Group (B) representing controls, consisted of 30 healthy females who had never experienced pregnancy with no or mild-severity NSLBP. Results: The statistical analysis between the two groups yielded significant differences in the right and left LPVMs’ tone (p = 0.002 and 0.015), relaxation time (p = 0.002 and 0.022), and creep (p = 0.013 and 0.008), respectively. On the other side, there were non-significant differences in the right and left LPVMs’ stiffness (p = 0.055 and 0.367) and elasticity (p = 0.115 and 0.231), respectively. The regression analysis’s final model indicated a strong overall performance (Nagelkerke: 1.00). Conclusions: The LPVMs of post-CB mothers with moderate-severity NSLBP showed remarkable changes in both contractile and viscous properties: muscle tone notably decreased, while viscosity increased. However, biomechanical properties like stiffness and elasticity showed negligible changes. This fitted regression analysis illustrated the holistic strong effect of LPVMs’ properties as risk factors contributing to post-CB NSLBP, emphasizing their consideration in diagnosis and intervention strategies for such cases. Full article