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1.
The purpose of this study was to examine the impact of age on running mechanics separately for male and female runners and to quantify sex differences in running mechanics and coordination variability for older runners. Kinematics and kinetics were captured for 20 younger (10 male) and 20 older (10 male) adults running overground at 3.5 m · s?1. A modified vector coding technique was used to calculate segment coordination variability. Lower extremity joint angles, moments and segment coordination variability were compared between age and sex groups. Significant sex–age interaction effects were found for heel-strike hip flexion and ankle in/eversion angles and peak ankle dorsiflexion angle. In older adults, mid-stance knee flexion angle, ankle inversion and abduction moments and hip abduction and external rotation moments differed by sex. Older compared with younger females had reduced coordination variability in the thigh–shank transverse plane couple but greater coordination variability for the shank rotation–foot eversion couple in early stance. These results suggest there may be a non-equivalent aging process in the movement mechanics for males and females. The age and sex differences in running mechanics and coordination variability highlight the need for sex-based analyses for future studies examining injury risk with age.  相似文献   

2.
The purpose of this study was to examine the differences in coordination variability in running gait between trained runners and non-runners using continuous relative phase (CRP) analysis. Lower extremity kinematic data were collected for 22 participants during the stance phase. The participants were assigned to either a runner or non-runner group based on running volume training. Segment coordination and coordination variability were calculated for selected hip–knee and knee–ankle couplings. Independent t-tests and magnitude-based inferences were used to compare the 2 groups. There were limited differences in the CRP and its variability among runners and non-runner groups. The runners group achieved moderately lower coordination compared with non-runners group in the phase angle for hip abduction/adduction and knee flexion/extension. The runners tended to show moderately lower coordination variability in the phase angle for knee flexion/extension and subtalar inversion/eversion in comparison to non-runners group. These results suggested that levels of experience as estimated from weekly training volume had little influence on coordination and its variability.  相似文献   

3.
This study examined the relationship between leg preference and knee mechanics in females during sidestepping. Three-dimensional data were recorded on 16 female collegiate footballers during a planned 45° sidestep manoeuvre with their preferred and non-preferred kicking leg. Knee kinematics and kinetics during initial contact, weight acceptance, peak push-off, and final push-off phases of sidestepping were analysed in both legs. The preferred leg showed trivial to small increases (ES = 0.19–0.36) in knee flexion angle at initial contact, weight acceptance, and peak push-off, and small increases (ES = 0.21–0.34) in peak power production and peak knee extension velocity. The non-preferred leg showed a trivial increase (ES = 0.10) in knee abduction angle during weight acceptance; small to moderate increases (ES = 0.22–0.64) in knee internal rotation angle at weight acceptance, peak push-off, and final push-off; a small increase (ES = 0.22) in knee abductor moment; and trivial increases (ES = 0.09–0.14) in peak power absorption and peak knee flexion velocity. The results of this study show that differences do exist between the preferred and non-preferred leg in females. The findings of this study will increase the knowledge base of anterior cruciate ligament injury in females and can aid in the design of more appropriate neuromuscular, plyometric, and strength training protocols for injury prevention.  相似文献   

4.
Because previous studies have suggested that there is a relationship between injury risk and inter-segment coordination, quantifying coordination between the segments is essential. Even though the midfoot and forefoot segments play important roles in dynamic tasks, previous studies have mostly focused on coordination between the shank and rearfoot segments. This study aimed to quantify coordination among rearfoot, midfoot, and forefoot segments during running. Eleven healthy young men ran on a treadmill. The coupling angle, representing inter-segment coordination, was calculated using a modified vector coding technique. The coupling angle was categorised into four coordination patterns. During the absorption phase, rearfoot–midfoot coordination in the frontal planes was mostly in-phase (rearfoot and midfoot eversion with similar amplitudes). The present study found that the eversion of the midfoot with respect to the rearfoot was comparable in magnitude to the eversion of the rearfoot with respect to the shank. A previous study has suggested that disruption of the coordination between the internal rotation of the shank and eversion of the rearfoot leads to running injuries such as anterior knee pain. Thus, these data might be used in the future to compare to individuals with foot deformities or running injuries.  相似文献   

5.
Female athletes are considered to exhibit knee and trunk motion that is characteristic of anterior cruciate ligament (ACL) injury. The aim of this study was to examine the in vivo motion of the trunk and knee during a cutting manoeuvre and determine the relationship between them. All participants (10 male and 10 female college athletes) performed a shuttle run cutting task with the left limb. Trunk inclination (forward and lateral) and knee joint angles (flexion/extension, abduction/adduction, and internal/external tibial rotation) were calculated. Differences between the sexes and associations between knee motion and trunk inclination were examined. An increase in trunk forward inclination was strongly correlated with an increase in knee flexion angle and moderately correlated with a decrease in the excursion of internal tibial rotation. An increase in right trunk lateral inclination was moderately correlated with an increase in excursion of internal tibial rotation. The results also showed differences between the sexes in trunk forward inclination, lateral inclination, and knee flexion angle, but no such differences in knee abduction or internal tibial rotation. Trunk inclination is related to knee flexion and excursion of internal tibial rotation. Female athletes demonstrate a low trunk forward inclination and knee flexion angle, a posture that resembles that of ACL injury.  相似文献   

6.
Abstract

Female athletes are considered to exhibit knee and trunk motion that is characteristic of anterior cruciate ligament (ACL) injury. The aim of this study was to examine the in vivo motion of the trunk and knee during a cutting manoeuvre and determine the relationship between them. All participants (10 male and 10 female college athletes) performed a shuttle run cutting task with the left limb. Trunk inclination (forward and lateral) and knee joint angles (flexion/extension, abduction/adduction, and internal/external tibial rotation) were calculated. Differences between the sexes and associations between knee motion and trunk inclination were examined. An increase in trunk forward inclination was strongly correlated with an increase in knee flexion angle and moderately correlated with a decrease in the excursion of internal tibial rotation. An increase in right trunk lateral inclination was moderately correlated with an increase in excursion of internal tibial rotation. The results also showed differences between the sexes in trunk forward inclination, lateral inclination, and knee flexion angle, but no such differences in knee abduction or internal tibial rotation. Trunk inclination is related to knee flexion and excursion of internal tibial rotation. Female athletes demonstrate a low trunk forward inclination and knee flexion angle, a posture that resembles that of ACL injury.  相似文献   

7.
Many studies have documented the association between mechanical deviations from normal and the presence or risk of injury. Some runners attempt to change mechanics by increasing running cadence. Previous work documented that increasing running cadence reduces deviations in mechanics tied to injury. The long-term effect of a cadence retraining intervention on running mechanics and energy expenditure is unknown. This study aimed to determine if increasing running cadence by 10% decreases running efficiency and changes kinematics and kinetics to make them less similar to those associated with injury. Additionally, this study aimed to determine if, after 6 weeks of cadence retraining, there would be carryover in kinematic and kinetic changes from an increased cadence state to a runner’s preferred running cadence without decreased running efficiency. We measured oxygen uptake, kinematic and kinetic data on six uninjured participants before and after a 6-week intervention. Increasing cadence did not result in decreased running efficiency but did result in decreases in stride length, hip adduction angle and hip abductor moment. Carryover was observed in runners’ post-intervention preferred running form as decreased hip adduction angle and vertical loading rate.  相似文献   

8.
This study investigated differences in lower-limb coordination and coordination variability between experienced and novice runners during a prolonged run. Thirty-four participants were categorised as either experienced (n = 17) or novice runners (n = 17). All participants performed a 31-min treadmill run at their individual anaerobic threshold speed, and lower-limb kinematic data were acquired in the sagittal plane at the beginning, middle, and end of the run. Lower-limb coordination and variability during the stance phase were quantified using a vector coding technique for hip-knee, knee-ankle, pelvis-thigh, thigh-shank, and shank-foot couplings. Repeated-measure analysis of covariance revealed that running experience and time had significant interactions on the coordination patterns for hip-knee and pelvis-thigh couplings. During the midstance, experienced runners exhibited a higher percentage of in-phase motion for pelvis-thigh and knee-ankle couplings while novice runners displayed a higher percentage of distal motion for pelvis-thigh coupling and anti-phase motion for hip-knee coupling. Experienced runners displayed more variability in hip-knee and shank-foot couplings, and novice runners had more variability in hip, knee, and thigh motion. Experienced and novice runners adapted to progressive fatigue through different lower-limb coordination patterns. Throughout the prolonged run, experienced runners demonstrated greater coordination variability and novice runners displayed greater joint and segment variability.  相似文献   

9.
This study aimed to establish the nature of lower extremity intra-limb coordination variability in cycling and to investigate the coordinative adaptations that occur in response to changes in cadence and work rate. Six trained and six untrained males performed nine pedalling bouts on a cycle ergometer at various cadences and work rates (60, 90, and 120 revolutions per minute (rpm) at 120, 210, and 300W). Three-dimensional kinematic data were collected and flexion/extension angles of the ankle, knee, and hip joints were subsequently calculated. These data were used to determine two intra-limb joint couplings [hip flexion/extension-knee flexion/extension (HK) and knee flexion/extension-ankle plantar-flexion/dorsi-flexion (KA)], which were analysed using continuous relative phase analysis. Trained participants displayed significantly (p < 0.05) lower coordination variability (6.6 +/- 4.0 degrees) than untrained participants (9.2 +/- 4.7 degrees). For the trained subjects, the KA coupling displayed significantly more in-phase motion in the 120 rpm (19.2 +/- 12.3 degrees) than the 60 (30 +/- 7.1 degrees) or 90 rpm (33.1 +/- 7.4 degrees) trials and the HK coupling displayed significantly more in-phase motion in the 90 (33.3 +/- 3.4 degrees) and 120 rpm (27.9 +/- 13.6 degrees) than in the 60 rpm trial (36.4 +/- 3.5 degrees). The results of this study suggest that variability may be detrimental to performance and that a higher cadence is beneficial. However, further study of on-road cycling is necessary before any recommendations can be made.  相似文献   

10.
The objective of this study was to compare the three-dimensional lower extremity running kinematics of young adult runners and elderly runners. Seventeen elderly adults (age 67-73 years) and 17 young adults (age 26-36 years) ran at 3.1 m x s(-1) on a treadmill while the movements of the lower extremity during the stance phase were recorded at 120 Hz using three-dimensional video. The three-dimensional kinematics of the lower limb segments and of the ankle and knee joints were determined, and selected variables were calculated to describe the movement. Our results suggest that elderly runners have a different movement pattern of the lower extremity from that of young adults during the stance phase of running. Compared with the young adults, the elderly runners had a substantial decrease in stride length (1.97 vs. 2.23 m; P = 0.01), an increase in stride frequency (1.58 vs. 1.37 Hz; P = 0.002), less knee flexion/extension range of motion (26 vs. 33 degrees ; P = 0.002), less tibial internal/external rotation range of motion (9 vs. 12 degrees ; P < 0.001), larger external rotation angle of the foot segment (toe-out angle) at the heel strike (-5.8 vs. -1.0 degrees ; P = 0.009), and greater asynchronies between the ankle and knee movements during running. These results may help to explain why elderly individuals could be more susceptible to running-related injuries.  相似文献   

11.
Abstract

The objective of this study was to compare the three-dimensional lower extremity running kinematics of young adult runners and elderly runners. Seventeen elderly adults (age 67–73 years) and 17 young adults (age 26–36 years) ran at 3.1 m · s?1 on a treadmill while the movements of the lower extremity during the stance phase were recorded at 120 Hz using three-dimensional video. The three-dimensional kinematics of the lower limb segments and of the ankle and knee joints were determined, and selected variables were calculated to describe the movement. Our results suggest that elderly runners have a different movement pattern of the lower extremity from that of young adults during the stance phase of running. Compared with the young adults, the elderly runners had a substantial decrease in stride length (1.97 vs. 2.23 m; P = 0.01), an increase in stride frequency (1.58 vs. 1.37 Hz; P = 0.002), less knee flexion/extension range of motion (26 vs. 33°; P = 0.002), less tibial internal/external rotation range of motion (9 vs. 12°; P < 0.001), larger external rotation angle of the foot segment (toe-out angle) at the heel strike (?5.8 vs. ?1.0°; P = 0.009), and greater asynchronies between the ankle and knee movements during running. These results may help to explain why elderly individuals could be more susceptible to running-related injuries.  相似文献   

12.
The purpose of this study was to investigate possible footfall pattern changes in habitual forefoot runners over a prolonged, exhaustive run. A prolonged run was performed to exhaustion in 14 habitual forefoot runners. Vertical ground reaction forces (VGRFs) and kinematics were collected at the beginning and end of the run. Ankle plantar flexor torque and triceps surae electromyographic activity were measured during pre- and post-run isometric contractions. By run’s end, there was an increase in VGRF loading rate and impact peak magnitude, greater dorsiflexion at foot contact and greater knee flexion angle throughout stance. Ankle plantar flexor torque decreased significantly from pre- to post-run tests. This was accompanied by a decrease in the integrated electromyographic activity (iEMG) output for the lateral and medial gastrocnemius. There were significant changes in landing mechanics for forefoot runners that indicate a transition towards more midfoot footfall patterns. A contributing factor may be ankle plantar flexor muscle fatigue that, at touchdown, is exposed to exaggerated eccentric loading. These findings suggest that a forefoot running pattern may become difficult to maintain in longer endurance events, and thus runners should pay attention to this in training to improve performance and mitigate potential injury.  相似文献   

13.
Many sports associated with anterior cruciate ligament (ACL) injury require athletes attend to a ball during participation. We investigated effects of attending to a ball on lower extremity mechanics during a side-cut maneuver and if these effects are consistent for males and females. Sagittal and frontal plane hip and knee kinematics and joint moments were measured during side-cut maneuvers in 19 male and 19 female National Collegiate Athletic Association division III basketball players. Participants also experienced two side-cut conditions that required attention to a ball. Our results did not indicate that the effect of attention varies with gender. However, during side-cut conditions while attending to a ball, internal knee adductor moment was 20% greater (p = 0.03) and peak knee flexion angle was 4 degrees larger (p < 0.01). Females demonstrated 5 degrees less hip flexion (p = 0.046), 12 degrees less knee flexion (p < 0.01), and 4 degrees more knee abduction (p = 0.026) at initial contact during all side-cut conditions than males. Attention to a ball may affect lower extremity mechanics relevant to ACL injury. The validity of laboratory studies of lower extremity mechanics for sports that include attention to a ball may be increased if participants are required to attend to a ball during the task.  相似文献   

14.
The purpose of this study was to compare the lower extremity inter-joint coordination of different collision forces runners during running braking phase. A dynamical system approach was used to analyse the inter-joint coordination parameters. Data were collected with six infra-red cameras and two force plates. According to the impact peak of the vertical ground reaction force, twenty habitually rearfoot-strike runners were categorised into three groups: high collision forces runners (HF group, n = 8), medium collision forces runners (MF group, n = 5), and low collision forces runners (LF group, n = 7). There were no significant differences among the three groups in the ankle and knee joint angle upon landing and in the running velocity (p > 0.05). The HF group produced significantly smaller deviation phase (DP) of the hip flexion/extension-knee flexion/extension during the braking phase compared with the MF and LF groups (p < 0.05). The DP of the hip flexion/extension-knee flexion/extension during the braking phase correlated negatively with the collision force (p < 0.05). The disparities regarding the flexibility of lower extremity inter-joint coordination were found in high collision forces runners. The efforts of the inter-joint coordination and the risk of running injuries need to be clarified further.  相似文献   

15.
ABSTRACT

The purpose was to quantify the effects of mid-flight whole-body and trunk rotation on knee mechanics in a double-leg landing. Eighteen male and 20 female participants completed a jump-landing-jump task in five conditions: no rotation, testing leg ipsilateral or contralateral (WBRC) to the whole-body rotation direction, and testing leg ipsilateral (TRI) or contralateral to the trunk rotation direction. The WBRC and TRI conditions demonstrated decreased knee flexion and increased knee abduction angles at initial contact (2.6 > Cohen’s dz > 0.3) and increased peak vertical ground reaction forces and knee adduction moments during the 100 ms after landing (1.7 > Cohen’s dz > 0.3). The TRI condition also showed the greatest knee internal rotation angles at initial contact and peak knee abduction and internal rotation angles and peak knee extension moments during the 100 ms after landing (2.0 > Cohen’s dz > 0.5). Whole-body rotation increased contralateral knee loading because of its primary role in decelerating medial-lateral velocities. Trunk rotation resulted in the greatest knee loading for the ipsilateral knee due to weight shifting and mechanical coupling between the trunk and lower extremities. These findings may help understand altered trunk motion in anterior cruciate ligament injuries.  相似文献   

16.
Many sports associated with anterior cruciate ligament (ACL) injury require athletes attend to a ball during participation. We investigated effects of attending to a ball on lower extremity mechanics during a side-cut maneuver and if these effects are consistent for males and females. Sagittal and frontal plane hip and knee kinematics and joint moments were measured during side-cut maneuvers in 19 male and 19 female National Collegiate Athletic Association division III basketball players. Participants also experienced two side-cut conditions that required attention to a ball. Our results did not indicate that the effect of attention varies with gender. However, during side-cut conditions while attending to a ball, internal knee adductor moment was 20% greater (p = 0.03) and peak knee flexion angle was 4° larger (p < 0.01). Females demonstrated 5° less hip flexion (p = 0.046), 12° less knee flexion (p < 0.01), and 4° more knee abduction (p = 0.026) at initial contact during all side-cut conditions than males. Attention to a ball may affect lower extremity mechanics relevant to ACL injury. The validity of laboratory studies of lower extremity mechanics for sports that include attention to a ball may be increased if participants are required to attend to a ball during the task.  相似文献   

17.
Increased lateral trunk bending to the injured side has been observed when ACL injuries occur. The purpose was to quantify the effect of mid-flight lateral trunk bending on center of mass (COM) positions and subsequent landing mechanics during a jump-landing task. Forty-one recreational athletes performed a jump-landing task with or without mid-flight lateral trunk bending. When the left and right trunk bending conditions were compared with the no trunk bending condition, participants moved the COM of the upper body to the bending direction, while the COM of the pelvis, ipsilateral leg, and contralateral leg moved away from the bending direction relative to the whole body COM. Participants demonstrated increased peak vertical ground reaction forces (VGRF) and knee valgus and internal rotation angles at peak VGRF for the ipsilateral leg, but decreased peak VGRF and knee internal rotation angles at peak VGRF and increased knee varus angles at peak VGRF for the contralateral leg. Mid-flight lateral trunk resulted in an asymmetric landing pattern associated with increased ACL loading for the ipsilateral leg. The findings may help to understand altered trunk motion during ACL injury events and the discrepancy in ACL injuries related to limb dominance in badminton and volleyball.  相似文献   

18.
目的:对辽宁省排球队女运动员下肢急停纵跳落地时的力矩和最大关节角度进行研究,以期对有膝关节损伤的排球运动员进行科学训练提供参考。方法:以14名辽宁省排球队女运动员为研究对象,将运动员分为两组,其中无伤组8人,损伤组6人,采用三维测力平台和红外光电运动捕捉系统,记录受试者在完成急停纵跳动作落地时的髋关节、膝关节、踝关节的力矩以及最大关节角度数据。结果:在急停纵跳落地时,损伤膝关节的旋转、收展力矩大于无伤组,屈伸力矩小于无伤组,损伤组的髋关节的屈伸、收展、旋转力矩均大于无伤组;损伤组的踝关节旋转力矩小于无伤组,收展力矩和屈伸力矩大于无伤组。损伤组的踝关节在屈伸、收展和旋转时的最大关节角度大于无伤组;损伤组的膝关节在屈伸和收展时的最大关节角度大于无伤组,旋转时小于无伤组;损伤的髋关节屈伸和收展时的最大关节角度大于无伤组,髋关节旋转时的最大关节角度左侧小于无伤组,右侧大于无伤组。结论:膝关节损伤的运动员完成急停纵跳动作落地时,通过代偿性改变增大髋关节力矩、增加膝关节旋转和收展力矩,增大踝关节收展和屈伸力矩,增加膝关节和髋关节在屈伸和收展时活动角度,增加膝关节屈伸和收展时活动角度来完成动作。  相似文献   

19.
The coronal and sagittal plane leg movements of 24 experienced male cyclists were assessed using video analysis while cycling on a Kingcycle windload simulator. The cyclists were grouped into those with a history of injury and an asymptomatic group on the basis of self-reported injury status. The ages, cycling experience, competition distances and competition speeds of the two groups were compared using Student's t-test. No significant differences (P < 0.05) were found for any of these variables. The maximum and minimum shank adduction, shank adduction velocities, knee flexion and ankle dorsiflexion values were also compared using Student's t-test. Significant differences were found at the point of maximum adduction (1.9 degrees; P = 0.019) and minimum dorsiflexion (4.9 degrees; P = 0.014). These differences indicated more dorsiflexion and greater abduction on the part of the symptomatic cyclists, supporting previous research that found that cyclists with a history of injury differ from those without a history of injury in the coronal plane leg movement patterns they adopt. Also, the most extreme medial position of the knee relative to the ankle occurred during knee extension. This supports the potential injury mechanism proposed by Francis (1986), which had previously only been examined using coronal plane kinematics.  相似文献   

20.
目的：探索跆拳道运动员前横踢动作下肢优势侧和非优势侧的运动生物力学特征差异性。方法：采用Vicon三维运动捕捉系统、Kistler三维测力台和Deado电子护具计分系统,采集13名跆拳道运动员前横踢动作下有效得分时髋、膝、踝关节的运动学和动力学数据,使用Visual3D软件对采集数据进行逆向运动学和动力学计算,并对结果采用配对样本T检验的方法进行差异性分析。结果：(1)进攻腿：髋关节屈曲力矩峰值、膝关节伸展力矩峰值优势侧大于非优势侧(p<0.05),膝关节屈曲最大角度优势侧大于非优势侧(p<0.01),髋关节伸展力矩峰值、外展最大角度非优势侧大于优势侧(p<0.01)。(2)支撑腿：髋关节屈曲幅度、屈曲功率峰值、外展功率峰值优势侧大于非优势侧(p<0.05),髋关节外展力矩峰值、膝关节伸展力矩峰值优势侧大于非优势侧(p<0.01),髋关节伸展角速度峰值、踝关节跖屈力矩峰值非优势侧大于优势侧(p<0.05),髋关节外展角速度峰值、膝关节屈曲力矩峰值、踝关节旋外角速度峰值非优势侧大于优势侧(p<0.01)。(3)进攻腿击打力度值及进攻腿和支撑腿垂直...  相似文献   

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