Search Results (59)

Background: Running-related injuries are often associated with biomechanical inefficiencies, particularly in the sagittal and frontal planes. This study evaluates the effects of three interventions—reduced heel-to-toe drop (HTD) shoes, increased cadence, and inversion foot orthoses—on key kinematic parameters: ankle dorsiflexion, knee flexion, and hip adduction (measured at foot strike and at their respective peak joint angles during the stance phase). Methods: Nineteen recreational runners (ten males and nine females; mean ± SD: age 26.4 ± 4.3 years; height 174.2 ± 7.8 cm; weight 68.3 ± 9.6 kg; BMI 22.5 ± 2.1 kg/m²) participated in a 3D motion capture study under five experimental conditions: baseline (10 mm HTD, no cadence adjustment, no foot orthoses), full intervention (5 mm HTD, +10% cadence, orthoses), and three partial interventions: HTD combined with orthoses, HTD combined with increased cadence, and cadence increase alone. Kinematic changes were analyzed for statistical significance. Results: The full intervention significantly increased ankle dorsiflexion at foot strike (from 8.11° to 10.44°; p = 0.005) and reduced peak knee flexion (from 45.43° to 43.07°; p = 0.003). Cadence adjustments consistently produced improvements, while orthoses and HTD alone showed effects on ankle flexion only. Conclusions: Combining structural (HTD and orthoses) and dynamic (cadence) modifications optimizes running biomechanics, providing evidence-based strategies for injury prevention and performance enhancement. Full article

Background: Runner’s dystonia (RD), a rare task-specific lower-limb dystonia affecting high-mileage runners, presents as abnormal lower-extremity muscle contractions during running. Treatment of RD is challenging and often confounded by significant diagnostic delays due to overlapping symptomatology with other conditions. This case series examines the relationship between stiff knee gait RD and musculoskeletal (MSK) knee pathology. Methods: Eight RD cases, evaluated at the NIH Movement Disorders Clinic since 2018, were retrospectively reviewed. Patients underwent neurological, biomechanical, and MSK evaluations, including 3D motion analysis, surface electromyography, and knee ultrasound. Therapeutic interventions, including botulinum neurotoxin (BoNT) injections, were assessed. Results: Seven patients demonstrated stiff knee gait subtypes, with all having ipsilateral and/or contralateral knee effusions or tendinopathies. Three patients who received MSK interventions (e.g., aspiration, corticosteroid injections) combined with BoNT therapy experienced significant symptom improvement. One patient with isolated foot dystonia displayed different biomechanical patterns without knee pathology. Conclusions: RD patients with stiff knee gait often exhibit knee pathology, most likely due to altered biomechanics and running history. Addressing both issues is essential for optimizing treatment outcomes, reducing pain, and improving function, especially since pain can trigger dystonia. Future research should determine the ideal sequence of interventions for RD patients with MSK issues to develop effective, personalized treatment algorithms. Full article

Objective: This study aimed to establish a dominant and non-dominant limb muscle strength evaluation model to evaluate the asymmetry of lower extremity muscle strength. Methods: The hip, knee, ankle flexors and extensors of 86 runners were evaluated separately in different contraction modes and at different movement speeds. A principal component analysis was used to establish a model for evaluating dominant and non-dominant lower extremity muscle strength and to comprehensively evaluate the asymmetry of lower extremity muscle strength. Results: Six main factors were present in both dominant and non-dominant indicators of lower extremity muscle strength, with dominant indicators of lower extremity muscle strength explaining 80.413% of the total variance and non-dominant indicators explaining 78.607% of the total variance. Conclusions: In a population of healthy male runners, there were differences in the symmetry of lower limbs in the comprehensive assessment model. The main contribution of the non-dominant side was the knee muscles, and the dominant side was the hip and knee muscles, so this difference should be considered in constructing future muscle strength evaluation models. It is critical to understanding the design and function of the human muscle system, and can reduce the number of meaningful tests we perform on diverse populations and help us reduce asymmetry. Full article

This study investigates the relationship between total running experience, defined as cumulative years of running multiplied by weekly mileage, and variability in lower leg joint kinematics during treadmill running. Twenty-seven male athletes participated, running while kinematic and kinetic data were collected. Linear regression revealed significant negative correlations between total running experience and variability in both knee and ankle joint range of motion (ROM). Specifically, ankle ROM variability (p = 0.001, R² = 0.35) and knee ROM variability (p = 0.002, R² = 0.32) were reduced in runners with more experience. A stepwise regression model further identified ankle ROM variability as a significant predictor (p = 0.033), explaining 44.25% of the variance in total running experience. A significant positive correlation between running experience and instantaneous vertical loading rate (IVLR) (p = 0.025, R² = 0.15) suggests that more experienced runners generate higher load rates. These findings indicate that more experienced runners exhibit more consistent and stable movement patterns, reflecting refined motor control. The results support the hypothesis that greater running experience is associated with reduced variability in movement patterns within a controlled environment, providing insights into the mechanisms that could contribute to enhanced performance and injury prevention. Full article

Background: Patellofemoral pain (PFP) is one of the most common multifactorial musculoskeletal pathologies affecting the knee joint. The prevalence of PFP in the general population ranges from 11% to 17%, with higher rates observed in specific groups such as females, runners, military personnel, and young athletes. To assess symptoms associated with PFP, the patellofemoral subscale (KOOS-PF) was developed, consisting of 11 questions that evaluate pain, stiffness, and quality of life. The KOOS-PF scale has already been validated and shown to be reliable in both its Spanish and Arabic versions. Objectives: The aim of this study was to assess the reliability and validity of the KOOS-PF scale in the Greek language among the Greek population with patellofemoral pain. Methods: Fifty-five participants aged 18–65 years who suffered from PFP were evaluated in two phases on the first and third days to determine the reliability and validity of the measures of KOOS-PF in the Greek language. Construct validity was assessed using the knee outcome survey scale—activities of daily living scale (KOS-ADLS). Reliability was measured through repeated measurements (test–retest) using intraclass coefficient correlation (ICC), standard error of measurement (SEM), and smallest detectable difference (SDD). Internal consistency was evaluated using Cronbach’s coefficient a. The significance level was set at 5% (α = 0.05). Results: The KOOS-PF measures showed high internal consistency reliability (Cronbach’s alpha 0.87, p = 0.05) and high test–retest reliability (ICC = 0.95, p = 0.05, SEM = 3.7, SDC = 13.57). Additionally, the Greek version of the KOOS-PF exhibited high construct validity when correlated with the KOS-ADLS scale (r = 0.72, p = 0.001). Conclusions: The KOOS-PF scale displayed high reliability and construct validity for measuring patellofemoral pain in the Greek population. Full article

Background/Objectives: The purpose of this study was to determine the effects of various muscle taping applications on running efficiency. Methods: Recreational runners (N = 14; 7 women; age = 22.80 ± 4.61 years; BMI = 25.08 ± 3.97 kg/m²) completed four bouts of treadmill running at a preferred speed. Each bout used a different taping technique, as follows: control (no tape), athletic tape, Kinesio tape, and a novel spring-type technique of Kinesio tape. Oxygen consumption, muscle activation of the rectus femoris and biceps femoris, and stride frequency were observed during each bout to assess running efficiency. The data for these variables were analyzed with repeated-measures ANOVAs (α = 0.05). Results: There were no differences among any of the four conditions for oxygen consumption (p = 0.232, η² = 0.103), muscle activation of the rectus femoris (p = 0.173, η² = 0.118) or biceps femoris (p = 0.085, η² = 0.184), or stride frequency (p = 0.230, η² = 0.107). Conclusions: None of the three taping methods tested in this study had a significant impact on oxygen consumption, agonist muscle activation, or stride frequency during short running bouts at a preferred speed compared to a control condition. There appeared to be no ergogenic benefit to the use of these taping techniques during this manner of activity. Runners opting to use a taping method to enhance joint stability at the knee during preferred-intensity running activity may do so without any substantial impact on their running efficiency. Full article

Previous studies on gender differences in running biomechanics have predominantly been limited to joint angles and have not investigated a potential influence of footwear condition. This study shall contribute to closing this gap. Lower body biomechanics of 37 recreational runners (19 f, 18 m) were analysed for eight footwear and two running speed conditions. Presenting the effect size Cliff’s Delta enabled the interpretation of gender differences across a variety of variables and conditions. Known gender differences such as a larger range of hip movement in female runners were confirmed. Further previously undiscovered gender differences in running biomechanics were identified. In women, the knee extensors are less involved in joint work. Instead, compared to men, the supinators contribute more to deceleration and the hip abductors to acceleration. In addition to differences in extent, women also show a temporal delay within certain variables. For the foot, ankle and shank, as well as for the distribution of joint work, gender differences were found to be dependent on footwear condition, while sagittal pelvis and non-sagittal hip and thigh kinematics are rather consistent. On average, smaller gender differences were found for an individual compared to a uniform running speed. Future studies on gender differences should consider the influence of footwear and running speed and should provide an accurate description of the footwear condition used. The findings of this study could be used for the development of gender-specific running shoes and sports and medical products and provide a foundation for the application of smart wearable devices in gender-specific training and rehabilitation. Full article

Runners achieve forward locomotion through diverse techniques. However, understanding the behavior of the involved kinematical variables remains incomplete, particularly when running overground and along an intensity spectrum. We aimed to characterize the biomechanical and physiological adaptations while running at low, moderate, heavy and severe intensities. Ten middle- and long-distance runners completed an incremental intermittent protocol of 800 m steps until exhaustion (1 km·h⁻¹ velocity increments and 30 s intervals) on an outdoor track field. Biomechanical data were captured using two high-resolution video cameras, and linear and angular kinematic variables were analyzed. With the intensity rise, a decrease in stride, step and contact times ([0.70–0.65], [0.35–0.33] and [0.42–0.37] s) and an increase in stride length and frequency and flight time ([3.13–3.52] m, [1.43–1.52] Hz and [0.28–0.29] s; p < 0.05) were observed, together with an increase in oxygen uptake and blood lactate concentrations ([54.7–67.6] mL∙kg⁻¹∙min⁻¹ and [3.1–10.2] mmol∙L⁻¹). A more flexed hip at initial contact and toe-off (152.02–149.36] and [165.70–163.64]) and knee at initial contact ([162.64–159.57]; p < 0.05) were also observed. A consistent gait pattern along each protocol step was exhibited, with minor changes without practical significance. Runners are constantly adapting their gait pattern, reflected in both biomechanical and physiological responses, both of which should be considered for better characterization. Full article

Background: Patellofemoral pain is one of the most common injuries in recreational runners, with significant implications for dynamic knee valgus. The knee valgus angle can be corrected surgically or with a more conservative non-operative approach. Increasing running cadence may be an effective biomechanical gait retraining intervention to reduce knee valgus and thus patellofemoral pain. The primary purpose of this study was to examine if an increase in cadence could change the knee valgus angle. Methods: Ten asymptomatic recreational runners were recorded running on a treadmill during control and experimental intervals. Each interval lasted five minutes, and participants ran at 100% and 110% of their baseline cadence. Peak angles of knee valgus were compared between both intervals using the video analysis software application Dartfish Express. A paired sample, a two-tailed t-test, was used to determine the significant difference between bilateral frontal plane knee angle measurements during both intervals. Results: The average decrease in knee valgus measured in control versus experimental intervals was 2.23° for the right leg and 2.05° for the left leg, with a significance of p < 0.001 and p < 0.001, respectively. Conclusion: The results indicated a statistically significant decrease in angles of dynamic knee valgus, attributable to increased cadence. These changes in knee valgus angle are likely to have a positive impact on preventing and reducing pain associated with PFP. Full article

Background: The purpose of this randomized cross-over controlled trial was to evaluate the biomechanical effects of ankle taping using rigid tape (RT) or kinesiotape (KT) compared to no taping during treadmill running in well-trained amateur runners. Methods: A total of 22 participants (15 men and 7 women) completed three running sessions on a treadmill, each lasting 30 min, under different conditions: no taping (CG), RT, and KT. Sagittal and frontal plane kinematics were analyzed using the Kinovea software to assess the ankle dorsiflexion, knee flexion, hip extension, tibial angle, foot strike pattern, heel eversion, and pelvic drop across three intervals (0–10, 10–20, and 20–30 min). Results: The results demonstrated no significant differences in sagittal plane variables (ankle dorsiflexion, knee flexion, hip extension, and cadence) or frontal plane variables (heel eversion and pelvic drop) between the CG, RT and KT groups at any time point. Although heel eversion significantly increased over time due to fatigue, the taping conditions did not affect running kinematics. Conclusions: These findings suggest that neither RT nor KT alters running biomechanics in well-trained runners over prolonged treadmill running. The study highlights that taping, commonly used to prevent ankle injuries, does not significantly modify lower limb kinematics in the absence of injury. Further research is needed to evaluate the effects of taping in novice or injured runners and under more demanding conditions, such as overground running. Full article

Background/Objectives: Sarcopenia is a muscular disease characterized by loss of muscular strength and function, affecting mainly women, and associated with increased mortality risk. The aim of this study was to compare active women with inactive women of different age groups regarding muscle mass, strength, and muscle quality. Methods: This study included 147 women (85 runners and 62 inactive), divided into <50 and ≥50 years old. Participants were evaluated for knee flexor and extensor peak torque (PT), body composition, and training habits. Results: For knee extensor muscles, there was an age group effect (F(2.146) = 40.5; p < 0.001) on absolute PT (Nm); an age group effect (F(2.146) = 44.1; p < 0.001) and a physical activity group effect (F(2.146) = 113.0; p < 0.001) on PT adjusted by body mass (Nm/kg); and an age group effect (F(2.146) = 36.9; p < 0.001) and a physical activity group effect (F(2.146) = 6.1; p = 0.014) on PT adjusted by lean mass (Nm/kgLM). There was no interaction effect. Conclusion: In both age groups, active women had greater strength and higher muscle quality than inactive women, but the difference in strength, muscle mass, and muscle quality between younger and older women were the same among runners and inactive women. Full article

The effects of occlusal splints on sport performance have already been studied, although their biomechanical impacts are often overlooked. We investigated the kinematical changes during running until exhaustion at severe intensity while wearing a mandibular advancement occlusal splint. Twelve trained runners completed (i) an incremental protocol on a track to determine their velocity corresponding to maximal oxygen uptake and (ii) two trials of square wave transition exercises at their velocity corresponding to maximal oxygen until exhaustion, wearing two occlusal splints (without and with mandibular advancement). Running kinematics were compared within laps performed during the square wave transition exercises and between splint conditions. The mandibular advancement occlusal splint increased the running distance covered (~1663 ± 402 vs. 1540 ± 397 m, p = 0.03), along with a noticeable lap effect in decreasing stride frequency (p = 0.04) and increasing stride length (p = 0.03) and duty factor (p < 0.001). No spatiotemporal differences were observed between splints, except for improved balance foot contact times in the mandibular advancement condition. An increased knee flexion angle at initial contact (p = 0.017) was noted along laps in the non-advancement condition, despite the fact that no differences between splints were found. Running patterns mainly shifted within laps rather than between conditions, indicating that a mandibular advancement occlusal splint had a trivial kinematical effect. Full article

There is limited validation for portable methods in evaluating high-speed running biomechanics, with inertial measurement unit (IMU) systems commonly used as wearables for this purpose. This study aimed to evaluate the validity of an IMU system in high-speed running compared to a 3D motion analysis system (MAS). One runner performed incremental treadmill running, from 12 to 18 km/h, on two separate days. Sagittal angles for the shank, knee, hip and pelvis were measured simultaneously with three IMUs and the MAS at the point of contact (POC), the timing when the foot initially hits the ground, as identified by IMU system acceleration, and compared to the POC identified via force plate. Agreement between the systems was evaluated using intra-class correlation coefficients, Pearson’s r, Bland–Altman limits of agreements, root mean square error and paired t-tests. The IMU system reliably determined POC (which subsequently was used to calculate stride time) and measured hip flexion angle and anterior pelvic tilt accurately and consistently at POC. However, it displayed inaccuracy and inconsistency in measuring knee flexion and shank angles at POC. This information provides confidence that a portable IMU system can aid in establishing baseline running biomechanics for performance optimisation, and/or inform injury prevention programs. Full article

Previous research has predominantly focused on the biomechanical effects of anterior–posterior foot motion during running, with comparatively less attention given to medial–lateral foot motion and its impact on lower limb biomechanical characteristics. We recruited 18 healthy runners who wore five different types of running shoes: regular shoes (NS), those with a 6 mm and 9 mm medial–lateral height difference in the forefoot (M6, M9), and those with a 6 mm and 9 mm lateral–medial height difference (L6, L9). Biomechanical parameters of lower limb joints during the stance phase of running, including range of motion, peak angular velocity, peak moment, power, and work, were analyzed. We used paired-sample t-tests and one-dimensional statistical parametric mapping (SPM1D) to compare joint biomechanics between shoes with varying height differences and NS. Under the L6 condition, notable differences occurred in the hip and knee flexion–extension moments during landing and push-off, accompanied by a significant increase in ankle dorsiflexion work and a significant decrease in inversion–eversion work. In contrast, the M9 condition resulted in decreased hip flexion–extension peak moment, power, and work in the sagittal plane. These findings indicate that varying forefoot medial–lateral height differences in running shoes significantly impact lower limb joint dynamics during the stance phase, particularly the L6 condition, potentially reducing knee injury risk and aiding gait improvement for overpronators. The findings offer valuable insights for sports injury prevention and athletic footwear design. However, further research is needed to understand the underlying mechanisms and practical implications for sports injury prevention and performance enhancement. Full article

Background: During city running or marathon races, shifts in level ground and up-and-down slopes are regularly encountered, resulting in changes in lower limb biomechanics. The longitudinal bending stiffness of the running shoe affects the running performance. Purpose: This research aimed to investigate the biomechanical changes in the lower limbs when transitioning from level ground to an uphill slope under different longitudinal bending stiffness (LBS) levels in running shoes. Methods: Fifteen male amateur runners were recruited and tested while wearing three different LBS running shoes. The participants were asked to pass the force platform with their right foot at a speed of 3.3 m/s ± 0.2. Kinematics data and GRFs were collected synchronously. Each participant completed and recorded ten successful experiments per pair of shoes. Results: The range of motion in the sagittal of the knee joint was reduced with the increase in the longitudinal bending stiffness. Positive work was increased in the sagittal plane of the ankle joint and reduced in the keen joint. The negative work of the knee joint increased in the sagittal plane. The positive work of the metatarsophalangeal joint in the sagittal plane increased. Conclusion: Transitioning from running on a level surface to running uphill, while wearing running shoes with high LBS, could lead to improved efficiency in lower limb function. However, the higher LBS of running shoes increases the energy absorption of the knee joint, potentially increasing the risk of knee injuries. Thus, amateurs should choose running shoes with optimal stiffness when running. Full article