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1.
Force plates represent the “gold standard” in measuring running kinetics to predict performance or to identify the sources of running-related injuries. As these measurements are generally limited to laboratory analyses, wireless high-quality sensors for measuring in the field are needed. This work analysed the accuracy and precision of a new wireless insole forcesensor for quantifying running-related kinetic parameters. Vertical ground reaction force (GRF) was simultaneously measured with pit-mounted force plates (1?kHz) and loadsol® sensors (100?Hz) under unshod forefoot and rearfoot running-step conditions. GRF data collections were repeated four times, each separated by 30 min treadmill running, to test influence of extended use. A repeated-measures ANOVA was used to identify differences between measurement devices. Additionally, mean bias and Bland–Altman limits of agreement (LoA) were calculated. We found a significant difference (p?® devices for these parameters. For these same parameters, the LoA analysis showed that 95% of all measurement differences between insole and force plate measurements were less than 12%, demonstrating high precision of the sensors. However, highly dynamic behaviour of GRF, such as force rate, is not yet sufficiently resolved by the insole devices, which is likely explained by the low sampling rate.  相似文献   

2.
In-shoe plantar pressure systems are commonly used in clinical and research settings to assess foot function during functional tasks. Recently, Tekscan® has updated their F-Scan® in-shoe plantar pressure system; however, this system’s test–retest reliability has not been established. Therefore, the purpose of this study was to determine the test–retest reliability of the F-Scan® 7 system in recreationally active individuals during treadmill walking. Seventeen healthy adults completed 2 sessions of treadmill walking. For each session, participants were fitted for shoes and pressure insoles and walked on a treadmill at a self-selected pace for 30 s. Following the sessions, the test–retest reliability peak pressure, pressure time integral, average pressure and pressure contact area over 4 regions of the foot (heel, mid-foot, forefoot and toes) was assessed by calculating intraclass coefficients (ICC 2,k) and coefficient of variation percentage (CoV%). Pressure contact area consistently had the highest ICCs and lowest CoV% (ICCs: 0.91–0.98; CoV%: 2.7–7.8%). Whereas, the forefoot and toe regions had the highest ICCs for all 4 measures (ICCs: 0.83–0.98; CoV%: 3.1–13.4%). During treadmill walking in healthy recreationally active individuals, the reliability of the new Tekscan F-Scan® ranged from poor to high and was dependent on the measure and region of the foot.  相似文献   

3.
The purpose of this study was to assess the validity of accelerometers using force plates (i.e., ground reaction force (GRF)) during the performance of different tasks of daily physical activity in children. Thirteen children (10.1 (range 5.4–15.7) years, 3 girls) wore two accelerometers (ActiGraph GT3X+ (ACT), GENEA (GEN)) at the hip that provide raw acceleration signals at 100 Hz. Participants completed different tasks (walking, jogging, running, landings from boxes of different height, rope skipping, dancing) on a force plate. GRF was collected for one step per trial (10 trials) for ambulatory movements and for all landings (10 trials), rope skips and dance procedures. Accelerometer outputs as peak loading (g) per activity were averaged. ANOVA, correlation analyses and Bland–Altman plots were computed to determine validity of accelerometers using GRF. There was a main effect of task with increasing acceleration values in tasks with increasing locomotion speed and landing height (P < 0.001). Data from ACT and GEN correlated with GRF (r = 0.90 and 0.89, respectively) and between each other (r = 0.98), but both accelerometers consistently overestimated GRF. The new generation of accelerometer models that allow raw signal detection are reasonably accurate to measure impact loading of bone in children, although they systematically overestimate GRF.  相似文献   

4.
Measurement of ground reaction force (GRF) in running provides a direct indication of the loads to which the body is subjected at each foot-ground contact, and can provide an objective explanation for performance outcomes. Traditionally, the collection of three orthogonal component GRF data in running requires an athlete to complete a series of return loops along a laboratory based runway, within which a force platform is embedded, in order to collect data from a discrete footfall. The major disadvantages associated with this GRF data collection methodology include the inability to assess multiple consecutive foot contacts and the fact that measurements are typically confined to the laboratory. The objective of this research was to investigate the potential for wearable instrumentation to be employed, in conjunction with artificial neural network (ANN) and multiple linear regression (MLR) models, for the estimation of GRF in middle distance running. A modular wearable data acquisition system was developed to acquire in-shoe force (ISF) data. Matched data sets from wearable instrumentation (source data) and force plate (target data) records were collected from elite middle-distance runners under controlled laboratory conditions for the purposes of ANN and MLR model development (MD) and model validation (MV). In terms of statistical measures of prediction accuracy the MLR model was found to provide a superior level of accuracy for the prediction of the vertical and medio-lateral components of GRF and alternatively, the ANN model provided the most accurate predictions of the anterior-posterior component of GRF. The prediction accuracy of each component of GRF was found to be governed by the inherent signal variability, in which case the vertical and anterior-posterior components were more reliable and subsequently predicted significantly more accurately than the medio-lateral component. The emerging capability for obtaining continuous GRF records from wearable instrumentation has the potential to permit unprecedented quantification of training stress and competition demands in running.  相似文献   

5.
Abstract

This study assessed the reliability and validity of segment measured accelerations in comparison to front foot contact (FFC) ground reaction force (GRF) during the delivery stride for cricket pace bowlers. Eleven recreational bowlers completed a 30-delivery bowling spell. Trunk- and tibia-mounted inertial measurement units (IMUs) were used to measure accelerations, converted to force, for comparisons to force plate GRF discrete measures. These measures included peak force, impulse and the continuous force–time curve in the vertical and braking (horizontal) planes. Reliability and validity was determined by intra-class correlation coefficients (ICC), coefficient of variation (CV), Bland–Altman plots, paired sample t-tests, Pearson’s correlation and one-dimensional (1D) statistical parametrical mapping (SPM). All ICC (0.90–0.98) and CV (4.23–7.41%) were acceptable, except for tibia-mounted IMU braking peak force (CV = 12.44%) and impulse (CV = 18.17%) and trunk vertical impulse (CV = 17.93%). Bland–Altman plots revealed wide limits of agreement between discrete IMU force signatures and force plate GRF. The 1D SPM outlined numerous significant (p < 0.01) differences between trunk- and tibia-located IMU-derived measures and force plate GRF traces in vertical and braking (horizontal) planes. The trunk- and tibia-mounted IMUs appeared to not represent the GRF experienced during pace bowling FFC when compared to a gold-standard force plate.  相似文献   

6.
The purpose of the study was to examine the vertical ground reaction force component when approaching the gait transition point from either a walk-to-run or run-to-walk perspective. The vertical ground reaction forces (VGRF) of five steps before gait transitions for both walk-to-run and run-to-walk were collected on a motor driven treadmill with embedded force plates. Transition specific characteristics of the VGRF were observed for both types of gait transition. Running peak force and time to peak force reduced dramatically in a quadratic fashion as approaching to the run-to-walk transition. The walking VGRF first peak increased linearly, and the second peak decreased quadratically prior to walk-to-run transition. Walking VGRF appearing to be more sensitive to acceleration than the running VGRF.  相似文献   

7.
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8.
The aim of this study was to evaluate the utility of the RT3 accelerometer in young children, compare its accuracy with heart rate monitoring, and develop an equation to predict energy expenditure from RT3 output. Forty-two volunteers (mean age 12.2 years, s = 1.1) exercised at two horizontal and graded walking speeds (4 and 6 km.h(-1), 0% grade and 6% grade), and one horizontal running speed (8 km.h(-1), 0% grade), on a treadmill. Energy expenditure and oxygen consumption (VO2) served as the criterion measures. Comparison of RT3 estimates (counts and energy expenditure) demonstrated significant differences at 4, 6, and 8 km.h(-1) on level ground (P < 0.01), while no significant differences were noted between horizontal and graded walking at 4 and 6 km.h(-1). Correlation and regression analyses indicated no advantage of vector magnitude over the vertical plane (X) alone. A strong relationship between RT3 estimates and indirect calorimetry across all speeds was obtained (r = 0.633-0.850, P < 0.01). A child-specific prediction equation (adjusted R2 = 0.753) was derived and cross-validated that offered a valid energy expenditure estimate for walking/running activities. Despite recognized limitations, the RT3 may be a useful tool for the assessment of children's physical activity during walking and running.  相似文献   

9.
目的:通过平板运动跑台和场地两种不同的测试方法,对我国成年男性走、跑过程中的气体代谢和能量消耗进行比较。方法:15名成年男性在平板运动跑台和场地完成4.8km/h、6.4 km/h、8.0 km/h三个速度的走、跑运动,使用Cortex MetaMax 3 B测定走、跑过程中的气体代谢指标变化并进行统计分析。结果:走、跑时平板运动跑台测试和场地测试之间气体指标、心率和能量消耗指标有明显差异。两种测试方法得来的数据存在线性相关。使用ICC系数和Bland-Altman法分析表明两种测试方法有非常显著的一致性和相关性。结论:相同速度下平板运动跑台走、跑和场地走、跑的能量消耗差异显著,只有直接测量场地走、跑的能量消耗才能反映日常生活中和体育健身活动中走、跑运动的真实状况。应用直线回归分析建立了平板运动跑台测试和场地测试两种方法之间的转换推导公式,根据跑台测试结果推算场地测试耗氧量和能量消耗,但由于样本量较少,该公式还需要进一步增加样本量进行验证。  相似文献   

10.
Abstract

Weight-bearing activity has been shown to increase bone mineral density. Our purpose was to measure vertical ground reaction forces (GRFs) during cyclocross-specific activities and compute their osteogenic index (OI). Twenty-five healthy cyclocross athletes participated. GRF was measured using pressure-sensitive insoles during seated and standing cycling and four cyclocross-specific activities: barrier flat, barrier uphill, uphill run-up, downhill run-up. Peak and mean GRF values, according to bodyweight, were determined for each activity. OI was computed using peak GRF and number of loading cycles. GRF and OI were compared across activities using repeated-measures ANOVA. Number of loading cycles per activity was 6(1) for barrier flat, 8(1) barrier uphill, 7(1) uphill run-up, 12(3) downhill run-up. All activities had significantly (P < 0.01) higher peak GRF, mean GRF values and OI when compared to both seated and standing cycling. The barrier flat condition (P < 0.01) had highest peak (2.9 times bodyweight) and mean GRF values (2.3 times bodyweight). Downhill run-up (P < 0.01) had the highest OI (6.5). GRF generated during the barrier flat activity is similar in magnitude to reported GRFs during running and hopping. Because cyclocross involves weight bearing components, it may be more beneficial to bone health than seated road cycling.  相似文献   

11.
Wireless sensing solutions that provide accurate long-term monitoring of walking and running gait characteristics in a real-world environment would be an excellent tool for sport scientist researchers and practitioners. The purpose of this study was to compare the performance of a body-worn wireless gyroscope-based gait analysis application to a marker-based motion capture system for the detection of heel-strike and toe-off and subsequent calculation of gait parameters during walking and running. The gait application consists of a set of wireless inertial sensors and an adaptive algorithm for the calculation of temporal gait parameters. Five healthy subjects were asked to walk and run on a treadmill at two different walking speeds (2 and 4?kph) and at a jogging (8?kph) and running (12?kph) speed. Data were simultaneously acquired from both systems. True error, percentage error and ICC scores indicate that the adaptive algorithm successfully calculated strides times across all speeds. However, results showed poor to moderate agreement for stance and swing times. We conclude that this gait analysis platform is valid for determining stride times in both walking and running. This is a useful application, particularly in the sporting arena, where long-term monitoring of running gait characteristics outside of the laboratory is of interest.  相似文献   

12.
This study assessed the validity of a tri-axial accelerometer worn on the upper body to estimate peak forces during running and change-of-direction tasks. Seventeen participants completed four different running and change-of-direction tasks (0°, 45°, 90°, and 180°; five trials per condition). Peak crania-caudal and resultant acceleration was converted to force and compared against peak force plate ground reaction force (GRF) in two formats (raw and smoothed). The resultant smoothed (10 Hz) and crania-caudal raw (except 180°) accelerometer values were not significantly different to resultant and vertical GRF for all running and change-of-direction tasks, respectively. Resultant accelerometer measures showed no to strong significant correlations (r = 0.00–0.76) and moderate to large measurement errors (coefficient of variation [CV] = 11.7–23.9%). Crania-caudal accelerometer measures showed small to moderate correlations (r = ? 0.26 to 0.39) and moderate to large measurement errors (CV = 15.0–20.6%). Accelerometers, within integrated micro-technology tracking devices and worn on the upper body, can provide a relative measure of peak impact force experienced during running and two change-of-direction tasks (45° and 90°) provided that resultant smoothed values are used.  相似文献   

13.
ABSTRACT

The capacity of foot-strike running patterns to influence the functional properties of the Achilles tendon is controversial. This study used transmission-mode ultrasound to investigate the influence of habitual running foot-strike pattern on Achilles tendon properties during barefoot walking and running. Fifteen runners with rearfoot (RFS) and 10 with a forefoot (FFS) foot-strike running pattern had ultrasound transmission velocity measured in the right Achilles tendon during barefoot walking (≈1.1 ms?1) and running (≈2.0 ms?1). Temporospatial gait parameters, ankle kinematics and vertical ground reaction force were simultaneously recorded. Statistical comparisons between foot-strike patterns were made using repeated measure ANOVAs. FFS was characterised by a significantly shorter stance duration (?4%), greater ankle dorsiflexion (+2°), and higher peak vertical ground reaction force (+20% bodyweight) than RFS running (P < .05). Both groups adopted a RFS pattern during walking, with only the relative timing of peak dorsiflexion (3%), ground reaction force (1–2%) and peak vertical force loading rates (22–23%) differing between groups (P < .05). Peak ultrasound transmission velocity in the Achilles tendon was significantly higher in FFS during walking (≈100 ms?1) and running (≈130 ms?1) than RFS (P < .05). Functional Achilles tendon properties differ with habitual footfall patterns in recreational runners.  相似文献   

14.
目的:对Cortex MetaLyzer 3B与Cortex MetaMax 3B测试气体代谢和能量消耗数据进行对比,以期对便携式与固定式气体代谢仪测试效果之间的差别进行评价。方法:15名成年男性在跑台完成2次4.8 km/h、6.4 km/h、8.0 km/h 3个速度的走跑,使用CortexMetaLyzer 3B与Cortex MetaMax 3B分别测定其运动过程中的气体代谢指标并进行统计分析。结果:1)便携式仪器测试组的摄氧量、通气量均高于固定式仪器测试组数据,且走跑时摄氧量增加有非常显著的差异;2)安静状态下心率和能量消耗无差别,走跑时便携式测试组心率和能量消耗均高于固定式测试组;3)两组测试数据存在线性相关;4)使用ICC系数和Bland-Altman法统计分析表明,两组测试数据有非常显著的相关性和一致性。结论:1)便携式气体代谢仪(MetaMax 3B)与固定式气体代谢仪(MetaLyzer 3B)对于运动时摄氧量、CO2呼出量的检测结果有显著差异;2)应用直线回归分析为两仪器测量数据的转换提供简便的公式。但由于样本量较少,该转换关系还需要进一步增加样本量进行验证。  相似文献   

15.
This study examined the haemolytic effects of an interval-based running task in fore-foot and rear-foot striking runners. Nineteen male distance runners (10 fore-foot, 9 rear-foot) completed 8 × 3 min repeats at 90% vVO2peak on a motorised treadmill. Pre- and post-exercise venous blood samples were analysed for serum haptoglobin to quantify the haemolytic response to running. Vertical ground reaction forces were also captured via a force plate beneath the treadmill belt. Haptoglobin levels were significantly decreased following exercise (P = 0.001) in both groups (but not between groups), suggesting that the running task created a haemolytic stress. The ground reaction force data showed strong effect sizes for a greater peak force (d = 1.20) and impulse (d = 1.37) in fore-foot runners, and a greater rate of force development (d = 2.74) in rear-foot runners. The lack of difference in haptoglobin response between groups may be explained by the trend for fore-foot runners to experience greater peak force and impulse during the stance phase of their running gait, potentially negating any impact of the greater rate of force development occurring from the rear-foot runners’ heel strike. Neither type of runner (fore-foot or rear-foot) appears more susceptible to technique-related foot-strike haemolysis.  相似文献   

16.
The role of the upper limbs in human locomotion and their influence on ground reaction force (GRF) have been extensively examined for walking and slow running. However, research has focused on unimpaired populations and has not evaluated high-speed running. In this study, the GRFs of an unilateral upper limb amputee athlete [missing right forearm, personal bests (PB): 400 m: 0:48.45 min, 800 m: 1:50.92 min] running at speeds of 5.4 and 8 m/s were collected using four floor-mounted force plates in a 100 m tartan track recording at 1000 Hz. The amputee athlete also performed trials with a running speed of 8 m/s wearing a weighted cuff on his impaired arm (0.5 and 1 kg, respectively). GRF data (without additional weight) were compared to those of an unimpaired athlete with similar PBs and anthropometry (age, height, weight). All data were evaluated for anterior–posterior, medial–lateral and vertical GRF as well as for stance phase (SP) duration and free moment (FM) values and a paired Student-t test (\(\alpha =5\) %) was performed on maximum and minimum values of the respective data sets comparing the left and right side of both athletes with each other, but no intersubjective comparisons were performed. The results revealed that vertical GRF showed significant differences for the impaired athlete at both running speeds comparing left and right foot, whereas the unimpaired athlete showed no significant differences in this matter at all. Medial–lateral GRF showed highly significant differences between the left and right foot of both athletes at both running speeds, whereas the results for anterior–posterior GRF and FM, however, showed ambiguous results. The trials with additional weight on the impaired limb led to significant differences for SP duration, but not for all conditions, and left–right differences did not change with additional weight. GRFs were found to differ in minimum medial–lateral GRF with no and heavy weight, maximum medial–lateral GRF within all weight conditions and maximum vertical GRF with no and heavy weight. For the FM, the overall pattern changed drastically and maximum FM showed a highly significant difference between the left and right foot, but none between the different conditions for both feet. Even though more significant asymmetries could be revealed for the impaired athlete, no general conclusion can be drawn at this point, given the limitations of the here presented study (low number of subjects available, anthropometric data of the impaired athlete could not be assessed).  相似文献   

17.
Rearfoot external eversion moments due to ground reaction forces (GRF) during running have been suggested to contribute to overuse running injuries. This study aimed to identify primary factors inducing these rearfoot external eversion moments. Fourteen healthy men ran barefoot across a force plate embedded in the middle of 30-m runway with 3.30 ± 0.17 m · s–1. Total rearfoot external eversion/inversion moments (Mtot) were broken down into the component Mxy due to medio-lateral GRF (Fxy) and the component Mz due to vertical GRF (Fz). Ankle joint centre height and medio-lateral distance from the centre of pressure to the ankle joint centre (a_cop) were calculated as the moment arm of these moments. Mxy dominated Mtot just after heel contact, with the magnitude strongly dependent on Fxy, which was most likely caused by the medio-lateral foot velocity before heel contact. Mz then became the main generator of Mtot throughout the first half of the stance phase, during which a_cop was the critical factor influencing the magnitude. Medio-lateral foot velocity before heel contact and medio-lateral distance from the centre of pressure to the ankle joint centre throughout the first half of the stance phase were identified as primary factors inducing the rearfoot external eversion moment.  相似文献   

18.
目的:确定跑步疲劳进程中下肢生物力学模式的变化,包括垂直和前后地面反作用力(ground reaction force,GRF)、垂直地面反作用力(vertical ground reaction force,vGRF)负载率、关节力学和刚度。方法:14名男性受试,采用Vicon红外摄像头和Bertec三维测力跑台,每隔2 min采集受试疲劳干预中的15 s GRF数据以及标记点轨迹。受试需穿着统一的跑鞋在测力跑台以恒速3.33 m/s跑至疲劳。满足以下标准时,干预结束:1)最大心率大于当下年龄的90%;2)受试不能继续跑步。对比受试跑至疲劳进程中4个时刻(疲劳前、33%、67%和100%)的着地冲击和下肢三关节触地角度、最大角度、关节活动度、角度变化量、关节蹬伸力矩和刚度等特征,采集并分析受试安静状态、疲劳后即刻、疲劳后4 min、疲劳后9 min的血乳酸浓度。结果:与疲劳前相比,1)血乳酸浓度在疲劳后即刻、疲劳后4 min和疲劳后9 min均显著增加;2)垂直/前后矢状轴GRF和vGRF负载率等参数在疲劳干预过程中均未观察到显著性变化;3)髋关节活动度在疲劳过程的33%、67%和100%时刻显著增加,膝关节活动度在67%时刻显著增加;4)踝关节运动学及踝、膝和髋关节的蹬伸力矩峰值均无变化;5)垂直刚度在67%和100%时刻显著降低。结论:疲劳干预过程中,GRF特征参数均没有明显变化,但是观察到下肢运动学和动力学模式的非线性改变。特别是从疲劳干预中期开始,人体下肢通过增加髋、膝关节活动度并减小垂直刚度实现“软着陆”策略,维持相似的冲击力特征,以减小长时间跑步可能带来损伤的风险。  相似文献   

19.
In this study, we examined whether self-selected overground running speed was consistent (1) with perceived overground speed on the treadmill and (2) among barefoot and three footwear conditions. Participants ran across a 20-m runway 10 times for each overground condition, with running speed calculated from kinematic data. For the treadmill condition, the participants were instructed to run at a speed that felt similar to their overground speed. This treadmill speed was chosen upon perception, with the display covered from the participant's view. Repeated-measures analysis of variance was used to detect differences in speed between overground and treadmill running, and also among barefoot and footwear conditions. Coefficient alpha (α) was calculated to determine repeatability of observations in each overground condition. The speed was higher during overground (3.65 ± 0.40 m/s) than treadmill (2.25 ± 0.75 m/s) running but did not differ among the barefoot and the three footwear conditions. Overall, overground speed was highly repeatable within an individual (α = 0.96–0.98). Researchers might consider using self-selected speed when investigating overground running mechanics with different foot–ground interface conditions. The influence of treadmill on the perception of speed may be related to shear force, running duration, joint load control, and/or other psychological factors.  相似文献   

20.
The aim of this study was to analyse gait variability and symmetry in race walkers. Eighteen senior and 17 junior athletes race walked on an instrumented treadmill (for 10 km and 5 km, respectively) at speeds equivalent to 103% of season’s best time for 20 km and 10 km, respectively. Spatio-temporal and ground reaction force (GRF) data were recorded at 2.5 km, and at 4.5, 6.5 and 8.5 km for a subsection of athletes. Gait variability was measured using median absolute deviation (MAD) whereas inter-leg symmetry was measured using the symmetry angle. Both groups showed low variability for step length (<0.9%), step frequency (<1.1%), contact time (≤1.2%) and vertical peak force values (<5%), and neither variability nor symmetry changed with distance walked. Junior athletes were more variable for both step length (P = 0.004) and loading force (P = 0.003); no differences for gait symmetry were found. Whereas there was little mean asymmetry overall, individual analyses identified asymmetry in several athletes (symmetry angle ≥ 1.2%). Importantly, asymmetrical step lengths were found in 12 athletes and could result from underlying imbalances. Coaches are advised to observe athletes on an individual basis to monitor for both variability and asymmetry.  相似文献   

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