Search Results (203)

Introduction: Hip abductor strength is essential for pelvic stability, lower limb alignment, and injury prevention. Weaknesses of the gluteus medius and minimus contribute to various musculoskeletal conditions. Lateral band walks and monster walks are elastic resistance exercises commonly used to target the hip abductors and external rotators in functional, weight-bearing tasks. Therefore, the aim was to summarize the current evidence on the biomechanics, muscle activation, and clinical applications of lateral and monster band walks. Methods: This narrative review was conducted following the SANRA guideline. A comprehensive literature search was performed across PubMed, Scopus, Web of Science, and SPORTDiscus up to April 2025. Studies on the biomechanics, electromyography, and clinical applications of lateral band walks and monster walks were included, alongside relevant evidence on hip abductor strengthening. Results: A total of 13 studies were included in the review, of which 4 specifically investigated lateral band walk and/or monster walk exercises. Lateral and monster walks elicit moderate to high activation of the gluteus medius and maximus, especially when performed with the band at the ankles or forefeet and in a semi-squat posture. This technique minimizes compensation from the tensor fasciae latae and promotes selective gluteal recruitment. Proper execution requires control of the trunk and pelvis, optimal squat depth, and consistent band tension. Anatomical factors (e.g., femoral torsion), sex differences, and postural variations may influence movement quality and necessitate tailored instruction. Full article

Background: Soccer performance is largely dependent on high-intensity, unilateral actions such as sprints, jumps, and changes of direction. These demands can lead to strength and power differences between limbs, highlighting the importance of individualised assessment in professional players. Rotational inertial devices offer a valuable method to evaluate and train these mechanical variables separately for each leg. The aim of this study was twofold: (a) to characterise the mechanical variables derived from several lower-body strength exercises performed on rotational inertial devices, all targeting the same muscle group; and (b) to compare the mechanical variables between the dominant and non-dominant leg for each exercise. Methods: Twenty-six male professional soccer players (age = 26.3 ± 5.1 years; height = 182.3 ± 0.6 cm; weight = 75.9 ± 5.9 kg; body mass index = 22.8 ± 1.1 kg/m²; fat mass percentage = 9.1 ± 0.6%; fat-free mass = 68.8 ± 5.3 kg), all belonging to the same professional Belgian team, voluntarily participated in this study. The players completed a single assessment session consisting of six unilateral exercises (i.e., quadriceps hip, hamstring knee, adductor, quadriceps knee, hamstring hip, and abductor). For each exercise, they performed two sets of eight repetitions with each leg (i.e., dominant and non-dominant) in a randomised order. Results: The quadriceps hip exercise resulted in higher mechanical values compared to the quadriceps knee exercise in both limbs (p < 0.004). Similarly, the hamstring hip exercise produced greater values across all variables and limbs (p < 0.004), except for peak force, where the hamstring knee exercise exhibited higher values (p < 0.004). The adductor exercise showed higher peak force values for the dominant limb (p < 0.004). The between-limb comparison revealed differences only in the abductor exercise (p < 0.004). Conclusions: These findings suggest the necessity of prioritising movement selection based on targeted outcomes, although it should be considered that the differences between limb differences are very limited. Full article

Background: Patients awaiting total hip arthroplasty (THA), particularly those with hip osteoarthritis (OA), face an elevated risk of osteoporosis due to age and gender-related factors. Osteoporosis, indicated by low bone mineral density (BMD), can affect implant osteointegration, long-term stability, and increase the likelihood of periprosthetic fractures. Despite these risks, osteoporosis is often underdiagnosed and undertreated in THA candidates. While several studies have addressed this issue in Northern populations, data on Southern European cohorts, particularly Italian patients, remain limited. This study aims to evaluate the prevalence of osteoporosis and vitamin D deficiency, as well as the rates of related treatments, in patients with hip osteoarthritis scheduled for THA. Methods: This single-center, retrospective study was conducted at Policlinico Universitario di TorVergata, Italy, involving 66 hip OA patients (35 men, 31 women; mean age 67.5 years). BMD was assessed at the femoral neck, total femur, and lumbar spine via DEXA, alongside vitamin D and PTH levels. Demographic data, ongoing anti-osteoporotic therapies, Harris Hip Score (HHS), and handgrip strength were recorded. Statistical analysis included t-tests and Pearson’s correlation. Osteoporosis was defined per WHO criteria, with significance set at p < 0.05. Results: In this study of 66 patients with hip osteoarthritis (35 men, 31 women; mean age 67.5 years), women exhibited significantly lower bone mineral density (BMD) at the total femur (−0.98 ± 1.42 vs. −0.08 ± 1.04; p < 0.05) and lumbar spine (−0.66 ± 1.74 vs. 0.67 ± 1.59; p < 0.05) compared to men. Handgrip strength was also significantly reduced in females (17.1 ± 8.2 kg) versus males (27.3 ± 10.3 kg; p < 0.05). Vitamin D levels were below 30 ng/mL in 89.4% of patients, and 63.6% had levels below 20 ng/mL; PTH levels were elevated (>65 pg/mL) in 54.5% of cases, indicating frequent secondary hyperparathyroidism. Only 9 patients were receiving vitamin D supplementation and none were on anti-osteoporotic treatment. Conclusions: These findings highlight the frequent coexistence of low BMD, vitamin D deficiency, and reduced muscle strength in THA candidates, suggesting a pattern of musculoskeletal vulnerability that warrants clinical attention. Full article

Alkaline phosphatase (ALP) deficiency has been linked to reduced physical performance, as seen in hypophosphatasia (HPP). However, its potential role in muscle function has not been fully explored. This was a cross-sectional study in 34 HPP adults and 34 matched healthy controls. Muscle strength was assessed using handgrip strength (HGS), considering values below the 10th percentile of the Spanish population as low strength. Muscle mass was evaluated using dual-energy X-ray absorptiometry and morphometric ultrasound. Bone mineral density (BMD) was measured at the lumbar spine, femoral neck, and total hip. The prevalence of low muscle strength was significantly higher in the HPP group compared to controls (30% vs. 6%; p = 0.009), with decreased HGS in the HPP group (p = 0.039). Positive associations were observed between ALP and femoral neck BMD, leg circumference, and fat-free mass and an inverse association with tricipital skinfold. Subjects with serum ALP activity below the sex-adjusted median had a significantly higher risk of low muscle strength independently of HPP diagnosis. ALP remained independently associated with HGS (p = 0.005), and a predictive model using ALP values showed strong capability to predict low-muscle-strength risk. Based on these results, we conclude circulating ALP levels are independently associated with muscle strength and may represent a useful biomarker for the early detection of muscle dysfunction. Future longitudinal or interventional studies are needed to assess whether ALP plays a causal role in muscle strength. Full article

Background: The methodology of ultrasound (US)-guided percutaneous neuromodulation (PNM) remains unclear. Objective: To determine the optimal stimulation frequency (3 Hz vs. 10 Hz) during the short-term application of US-guided PNM on the sciatic nerve, we assessed the therapeutic benefits, including pain reduction, hip passive internal rotation range of motion (IR-ROM), balance, and functionality, in patients with chronic low back pain (LBP). Methods: Forty patients with LBP were randomly assigned to two groups, each receiving isolated percutaneous electrical stimulation of the sciatic nerve. One group received stimulation at 3 Hz, while the other received stimulation at 10 Hz. Pain intensity, hip passive IR-ROM, hip muscle strength, and the Oswestry Disability Index (ODI) were measured before and one week after the intervention. Results: Both interventions significantly reduced pain and improved ROM, balance, and functionality after one week (p = 0.001). However, significant between-group (treatment × time) differences were observed for pain intensity (p = 0.001) and flexion strength in the non-intervention limb (p = 0.01), though the effect size was small (η² = 0.1). Conclusions: US-guided PNM applied to the sciatic nerve was more effective at 3 Hz than at 10 Hz in relieving pain intensity in patients with LBP. Full article

The response to perturbations in the gait of elderly and young individuals can differ due to various factors, such as age-related changes in sensorimotor function, muscle strength, and balance control. This study aimed to identify and compare compensatory kinematic and kinetic gait strategies in response to sudden treadmill perturbations applied during the Pre-Swing phase in young and older adults. The analysis focused on determining age-related differences in joint behavior and force production under perturbation stress, with implications for fall prevention. Twenty-one young and an equal number of elderly healthy females walked on a treadmill in a virtual environment (GRAIL, Motek). Unexpected perturbations were applied five times. Principal Component Analysis (PCA) and k-means clustering identified three distinct compensatory strategies per limb. Young adults primarily employed Strategies I (42.2%) and II (40%), while older adults most often selected Strategy II (45.5%). Statistical analysis (SPM and Mann-Whitney U test, p = 0.05) showed significant between-group differences in joint angles and torques across the gait cycle. For instance, in Strategy I, young participants had significantly lower ankle plantarflexion angles (p < 0.01) and hip extension torques (p < 0.05) compared to the elderly. Strategy II in older adults showed significantly higher vGRF minimums (p < 0.01) and anterior-posterior GRF peaks (p < 0.001). The elderly adopted strategies compatible with their neuromuscular capacity rather than those minimizing joint load, as observed in the young group. These findings offer novel insights into age-related compensatory mechanisms and highlight the importance of tailored fall-prevention strategies based on biomechanical response patterns. Full article

Background: Total hip arthroplasty (THA) improves the quality of life by alleviating pain and restoring function. The optimal pain control with minimal muscle weakness is paramount for early rehabilitation and for reducing complications. Although PROSPECT and ICAROS guidelines recommend the Fascia Iliaca Compartment Block (FICB), it is associated with insufficient pain relief and a prolonged quadriceps motor block. The association of the PENG (Pericapsular Nerve Group) with LFCN (lateral femoral cutaneous nerve) blocks may address these limitations, provide improved motor-sparing pain control, and offer a more tailored approach that enhances both an early postoperative recovery and patient satisfaction. Methods: A randomized controlled trial (November 2023–July 2024) compared the PENG + LFCN to the FICB in patients undergoing elective THAs under spinal anesthesia. The primary outcome was quadriceps weakness at 6 h post-block. Secondary outcomes included the degree of hip flexion and pain scores at 6, 24, and 48 h post-block, opioid consumption, and time to ambulation. Results: Fifty-eight patients were randomized (twenty-nine per group). The PENG + LFCN group achieved a significantly greater muscle strength (MRC: 4 [4; 4] vs. 3 [3; 4], p < 0.0001) and better hip flexion at all measured moments (6 h: 45° [37; 60] vs. 30° [25; 43], 24h: 59° [49; 66] vs. 47° [36; 50], 48 h: 62° [55; 70] vs. 50° [40; 55], all p < 0.0001). Resting pain was lower in the PENG + LFCN group (0 [0; 1], 0 [0; 2], and 0 [0; 1] vs. 2 [0; 3], 1 [0; 3], 1 [0; 3]), as was the dynamic pain during movement (1 [0; 2], 2 [2; 4], and 2 [1; 2] vs. 3 [2; 5], 3 [2; 4], and 3 [1; 3]; all p < 0.001), along with a lower total opioid consumption (0 [0; 0] vs. 7.5 [7.5; 22.5] MME, p < 0.001). Conclusions: The PENG + LFCN block outperformed the FICB in muscle strength, hip flexion, pain control, and opioid use, suggesting it may be a more effective option for THAs. Full article

Background: High-intensity intermittent training (HIIT) has been proven to improve cardio-metabolic and respiratory health outcomes. In addition, 20-hydroxyecdysone from plant extracts has been studied for its anabolic effects. However, studies examining these two interventions in individuals who are obese or overweight are limited. This study, thus, examined the effects of HIIT combined with Asparagus officinalis (A. officinalis) extract supplementation on cardiovascular and pulmonary function parameters in obese and overweight individuals. Methods: Seventy-two obese and overweight participants were randomized into four groups (n = 18 each): the control (CON) group; HIIT group (HIIT for 3 days/week); AOE (A. officinalis extract) group (supplementation with 20E at 1.71 mg/kg/day); and HIIT + AOE group. Pre- and 12-week post-intervention measures included heart rate (HR), HR variability, endothelial function, blood pressure (BP), BP variability, pulmonary function and volume, respiratory muscle strength, chest expansion, and body composition. Results: The HIIT + AOE group showed better HR variability with higher high-frequency power and a lower low-frequency/high-frequency ratio (both p = 0.038) compared to the CON group. The peak blood flow increased in both the HIIT (p = 0.03) and HIIT + AOE (p = 0.028) groups, but only the HIIT group had a shorter vascular recovery time (p = 0.048). The maximum expiratory pressure was increased in both the HIIT and HIIT + AOE groups compared to the CON group (p = 0.029 and p = 0.041). The ratio of forced expiratory volume in one second to forced vital capacity, the percent-predicted FEV₁/FVC, and chest wall expansion were higher in the HIIT + AOE group than in the CON group (p = 0.047, p = 0.038, and p = 0.001). The waist-to-hip ratio was lower in the HIIT + AOE group than in the CON group (p = 0.043). There were no significant differences in HR, BP, BP variability, or pulmonary volume parameters among groups. Conclusions: The combination of HIIT with A. officinalis extract supplementation markedly improves HR variability. Moreover, it also greatly improves expiratory muscle strength, chest wall expansion, pulmonary function, and body composition parameters in obese and overweight individuals. Full article

Hip fractures represent a significant public health challenge, particularly among the elderly, due to their high incidence, morbidity, and mortality rates. This review provides a comprehensive understanding of hip fractures through clinical, biomaterial, and biomechanical perspectives. Clinically, we examined key risk factors, including age, bone mineral density, and the high prevalence of falls, which account for over 95% of hip fractures. However, current clinical tools, such as FRAX, have notable limitations in accurately assessing fracture risk in individuals due to their reliance on statistical models, the treatment of interdependent risk factors as independent, and the omission of key variables like diabetes. From a biomaterial perspective, we analyzed bone composition—specifically the balance of inorganic minerals, organic proteins, and water—and its role in determining bone strength and fracture susceptibility. Various risk factors ultimately influence this composition balance, thereby affecting bone strength. Therefore, accurately measuring bone composition may provide a more reliable assessment of hip fracture risk. Although emerging imaging technologies such as dual-energy CT and MRI show promise for in vivo assessments of bone composition, these techniques still face significant challenges and remain an active area of research. Biomechanically, we explored the forces generated during falls, noting that impact forces can vastly exceed normal physiological loads and may exploit the anisotropic properties of bone, leading to fractures even in healthy individuals with strong bones. This understanding emphasizes the critical role of fall prevention in reducing fracture risk and highlights the limitations of using fall-induced fracture incidence as a validation metric for clinical assessment tools. Lastly, we discuss preventive strategies, including passive measures like environmental modifications for individuals diagnosed with low bone strength and proactive measures such as muscle strengthening and cognitive training. While passive measures are necessary for immediate protection, proactive strategies are more effective in the long term by addressing underlying risk factors for falls and promoting sustained bone health. This interdisciplinary review underscores the need to integrate clinical, biomaterial, and biomechanical factors to improve diagnostic accuracy, prevention, and treatment strategies for hip fractures, ultimately advancing public health outcomes in aging populations. Full article

Background/Objectives: Sedentary office workers (SOWs) often adopt prolonged sitting postures, which potentially disrupt the lumbar–pelvic rhythm (LPR) and contribute to lower back pain (LBP). This study aimed to clarify the group differences in LPR and related physical factors between SOWs with and without LBP. Methods: Sixty-three SOWs were divided into LBP (n = 30) and non-LBP (n = 33) groups. The lumbar flexion angle (LF) and lumbar–hip angle difference (LHD), which are indicators of LPR, were measured using inertial sensors during trunk flexion. Hip flexion muscle strength (HFMS) and hip-extension muscle strength (HEMS) were assessed using handheld dynamometry. Hip joint range of motion (ROM) was measured using a goniometer. Lumbar proprioception was evaluated via active joint repositioning, and pain and perception were assessed using the Visual Analog Scale, Oswestry Disability Index, and Fremantle Back Awareness Questionnaire. Results: Multiple regression analysis showed significantly greater LF (estimated regression coefficient [ERC]: −2.9, p < 0.05) and LHD (ERC: −5.5, p < 0.05) during early trunk flexion (ETF) in the LBP group. In the LBP group, LHD during ETF and late trunk flexion were positively correlated with HFMS, and HFMS was correlated with HEMS. Conclusions: HFMS may contribute to an altered LPR in SOWs with LBP. Full article

This meta-analysis investigated muscle activity and sprint biomechanics by reviewing EMG, kinematic, and kinetic studies, with a focus on changes across sprint phases and the effects of fatigue. Following PRISMA 2020 guidelines, twelve studies were selected from databases such as PubMed and Scopus, analyzing lower limb muscles (e.g., biceps femoris, semitendinosus, gluteus maximus) and biomechanical variables like step length, stride frequency, and ground reaction forces. Using random-effects models and meta-regression, the analysis revealed that increased sprint speed is associated with greater activation of the posterior thigh muscles and gluteus maximus. The biceps femoris peaks in the late swing phase (~110% MVC), while the gluteus maximus is most active in early stance. Sprinting faster typically results in a 15–20% increase in step length and moderate changes in stride frequency. Fatigue causes earlier muscle activation, reduced hip and knee flexion, and longer ground contact times, which may impair efficiency and raise injury risk. A strong linear relationship (R² = 0.881, p < 0.001) was found between sprint speed and muscle activation, with activation increasing by ~6.3% MVC per 1 m/s. These findings highlight the importance of hamstring and gluteal strength, as well as fatigue resistance, in sprint training and injury prevention. Full article

Background: Vitamin D is vital for musculoskeletal health, with emerging evidence highlighting its role in muscle function. While its preoperative and postoperative benefits for bone health are well documented, the effect of vitamin D supplementation on post-surgical muscle recovery remains underexplored. This systematic review consolidates current evidence on the impact of vitamin D supplementation in enhancing muscle strength following surgery. Methods: This review adhered to PRISMA guidelines and was registered on PROSPERO. A systematic search of PubMed, EMBASE, and Cochrane databases was conducted, covering articles from inception to 15 January 2025. Studies evaluating the effect of vitamin D supplementation on muscle strength in surgical contexts were included. Data extraction focused on study design, population demographics, vitamin D dosage, timing, and measured outcomes. A narrative synthesis was performed due to heterogeneity in study designs and outcomes. Results: From 701 initial records, 10 studies met the inclusion criteria. The findings indicate that vitamin D supplementation, particularly high-dose regimens administered preoperatively or early postoperatively, significantly improves muscle strength and functional outcomes in orthopaedic surgeries, such as hip and knee replacements, and bariatric surgeries. The benefits varied by surgical type, baseline vitamin D levels, and supplementation strategy. However, inconsistent dosing regimens and limited long-term follow-up studies hinder conclusive evidence. Conclusions: Vitamin D supplementation demonstrates potential in enhancing post-surgical muscle recovery and functional outcomes. Tailored supplementation strategies, based on patient-specific needs and surgical context, are essential. Future research should address optimal dosing regimens and evaluate long-term impacts on recovery and quality of life. Full article

Background/Objectives: Groin and hip injuries are common in sport, and muscle weakness has been identified as an intrinsic risk factor. So, analyzing the strength of the hip musculature becomes important. To date, there are no hip adductor isometric strength tests on force platforms. This study aims to analyze the intra-test reliability of a hip adductor strength test using force platforms. Methods: The study sample comprised 13 male professional soccer players with an average age of 22.3 ± 3 years, body mass of 75.8 ± 5.4 kg, and height of 1.8 ± 0.1 m. Assessments were conducted on a uniaxial force platform. The variables analyzed are peak force (PF), rate of force development (RFD), and impulse. Intra-test reliability was evaluated using the coefficient of variation (CV), intraclass correlation coefficient (ICC), and Bland–Altman plots. Results: Acceptable levels of reliability were identified solely for the variable of peak force, with CV values of D = 5.7% for the dominant profile and ND = 5.4% for the non-dominant profile. Furthermore, moderate and good relative reliability were observed in peak force for the dominant (ICC = 0.706) and non-dominant (ICC = 0.819) profiles, respectively. However, the remaining time-related variables, RFD and impulse, did not achieve acceptable levels of absolute reliability (CV > 10%) and displayed poor to moderate relative reliability. Conclusions: In summary, PF during the hip adductor isometric strength test demonstrated acceptable absolute and commendable relative reliability. Conversely, the time-related variables, specifically RFD and impulse, yielded unsatisfactory absolute and relative reliability levels. Full article

Background/Objectives: Optimal activation of the quadriceps femoris, particularly the vastus medialis, while minimizing excessive activation of the vastus lateralis, is crucial for treating knee injuries like ACL ruptures and patellofemoral pain syndrome. Restoring proper muscle balance may enhance rehabilitation outcomes, but effective strategies for modulating muscle activity remain unclear. High-velocity low-amplitude hip manipulation has shown potential to influence neuromuscular function, yet its impact on quadriceps activation during knee extension has not been well studied. Therefore, the main aim of this study is to examine the effects of a single session of high-velocity low-amplitude hip manipulation on quadriceps femoris muscle activation and maximum voluntary contraction during knee extension. Methods: This study utilizes a randomized controlled design. Thirty physically active men and women (mean age: 21.9 ± 1.7 years) were randomly assigned to either an experimental group (n = 15; receiving hip joint manipulation) or a control group (n = 15; undergoing a sham intervention). Participants in the intervention group received a treatment involving hip manipulation and short-duration traction. Muscle activity of the rectus femoris, vastus lateralis, and vastus medialis was assessed using surface electromyography before and after the intervention, while muscle performance was measured by evaluating isometric knee extension strength in the lower limb. The isometric strength test was conducted in a seated position with the knee flexed at 60 degrees in Biodex System 4. Results: This study finds that the experimental group had significantly higher vastus lateralis mean amplitude (p = 0.020; effect size = 0.186) and vastus medialis mean amplitude (p < 0.001; effect size = 0.577) of electromyography root mean square electromyography compared to the control group. The experimental group also showed greater vastus medialis max amplitude (p < 0.001; effect size = 0.435). No significant differences were noted for rectus femoris mean amplitude (p = 0.078; effect size = 0.110), vastus lateralis max amplitude (p = 0.363; effect size = 0.031), rectus femoris max amplitude (p = 0.069; effect size = 0.117), or median frequency of the raw electromyography signal across muscle groups. Conclusions: In conclusion, high-velocity low-amplitude hip manipulation significantly enhances vastus medialis activation, highlighting its potential to improve quadriceps balance. These findings support the incorporation of hip manipulation into rehabilitation protocols. Full article

This study aims to address the clinical needs of hemiplegic and stroke patients with lower limb motor impairments, including gait abnormalities, muscle weakness, and loss of motor coordination during rehabilitation. To achieve this, it proposes an innovative design method for a lower limb rehabilitation training system based on Bayesian networks and parallel mechanisms. A Bayesian network model is constructed based on expert knowledge and structural mechanics analysis, considering key factors such as rehabilitation scenarios, motion trajectory deviations, and rehabilitation goals. By utilizing the motion characteristics of parallel mechanisms, we designed a rehabilitation training device that supports multidimensional gait correction. A three-dimensional digital model is developed, and multi-posture ergonomic simulations are conducted. The study focuses on quantitatively assessing the kinematic characteristics of the hip, knee, and ankle joints while wearing the device, establishing a comprehensive evaluation system that includes range of motion (ROM), dynamic load, and optimization matching of motion trajectories. Kinematic analysis verifies that the structural design of the device is reasonable, aiding in improving patients’ gait, enhancing strength, and restoring flexibility. The Bayesian network model achieves personalized rehabilitation goal optimization through dynamic probability updates. The design of parallel mechanisms significantly expands the range of joint motion, such as enhancing hip sagittal plane mobility and reducing dynamic load, thereby validating the notable optimization effect of parallel mechanisms on gait rehabilitation. Full article