Estimating youth locomotion ground reaction forces using an accelerometer-based activity monitor (original) (raw)
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Validation of two accelerometers to determine mechanical loading of physical activities in children
Journal of sports sciences, 2015
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 (...
Normative ground reaction force data for able-bodied and below-knee-amputee children during walking
Journal of Pediatric Orthopaedics
The purpose of this investigation was to develop normative ground reaction force data for able-bodied (AB) and trans-tibial amputee (TTA) children during running. Two hundred AB (mean age 9.4 years, range 7-12) and 21 TTA (mean age 11.1 years, range 5-17) children ran (2.2 m/s±10%) over a force platform. Ground reaction force data were normalized, averaged within groups and plotted to produce force-time curves characterizing the different leg types (i.e. able-bodied, nonprosthetic and prosthetic). In addition, discrete variables characterizing the leg type differences were determined.
Prosthetics and orthotics international, 1993
The purpose of this investigation was to develop normative ground reaction force data for able-bodied (AB) and trans-tibial amputee (TTA) children during running. Two hundred AB (mean age 9.4 years, range 7-12) and 21 TTA (mean age 11.1 years, range 5-17) children ran (2.2 m/s +/- 10%) over a force platform. Ground reaction force data were normalized, averaged within groups and plotted to produce force-time curves characterizing the different leg types (i.e. able-bodied, non-prosthetic and prosthetic). In addition, discrete variables characterizing the leg type differences were determined. One way ANOVA determined significant differences between variables and a TukeyB Post Hoc analysis defined which variables were significantly different (p < 0.05). Results generally indicated differences between the three leg types with the non-prosthetic leg indicating greater forces than the prosthetic and AB legs. The results of this investigation provide normative ground reaction force data ...
2008
The purpose of this study was to identify the relationship between GRF and the stability level of the lower extremity to define the risk of running-related injuries. 13 participants were divided to two groups (previous running injury; no previous running injury) and performed a Single-leg Excursion Test (SET), and ran across a force plate to measure GRFs. Results showed a moderate negative correlation, (r(10) =-0.620, P < 0.05). The injury group had higher GRF and lower SET scores as compared to the no injury group. Runners that can reduce the GRF and improve their stability level in the 'lower extremity by performing proper strength and stability training may reduce the risk of injuries from running activities.
Study on estimation of peak Ground Reaction Forces using tibial accelerations in running
2013 IEEE Eighth International Conference on Intelligent Sensors, Sensor Networks and Information Processing, 2013
Ground Reaction Forces (GRF) are exerted by a surface as a reaction to a person standing, walking or running on the ground. In elite and recreational sports, GRFs are measured and studied to facilitate performance improvement and enhance injury management. Although, GRFs can be measured accurately using force platforms, such a hardware can only operate in a constrained laboratory environment and hence may limit and potentially alter a subject's natural walking or running pattern. Alternatively, a system that can measure GRFs in a more natural environment with less constraints can provide valuable insights of how humans move naturally given different gait patterns, terrain conditions and shoe types. In this regard, inertial Micro-Electrical-Mechanical-Sensors (MEMS), such as accelerometers and gyroscopes, are a promising alternative to laboratory constrained data collection systems. Kinematics of various body parts, such as their accelerations and angular velocities, can be quantified by attaching these sensors at points of interest on human body. In this paper, we investigate the relationship between the vertical GRF peaks measured by an OR6 series AMTI force plate, and accelerations along the tibial axis measured by a MEMS sensor. Our measuring system consists of two low-power wireless inertial units (ViPerform), containing one tri-axis accelerometer placed on the medial tibia of each leg. We investigate the accuracy of the measured and estimated GRF peak in 3 subjects, by means of the Root Mean Square Error (RMSE). The RMSE achieved across the speeds of 6, 9, 12, 15, 18, 21km/h and sprinting were 157 and 151N , 106 and 153N , and 130 and 162N for the left and right legs respectively for Subjects 1, 2, and 3. We achieved normalized errors of 6.1%, 5.9% and 5.4% for all the subjects.
Ground Reaction Forces during the Biomechanical Gait Analysis in Children
The objective of this article was to review the aspects related to the biomechanical variables that influence human gait and to understand how the ground reaction forces act during the process of ambulation. The research was made through Scopus and Google Scholar database and the key words used were: "gait", "children", "walk" and "ground reaction forces". Gait evaluation is used in many fieldsto make diagnoses, recommend interventions and monitor their effect. Muscle recruitment, immature stride dynamics and, strategies of equilibrium control, immature sensory integration during stance, are some of various biomechanical and neural factors related to the kinetic pattern of walking in children. There are different biomechanical parameters and methodologies applied to analyze the gait pattern in children, and severalstudies have addressed medical treatments and their influence in the gait parameters. Therefore, the study of the relationshipbetween biomechanical variables and the gait maturity of the children is important to the development of new treatments and interventions in this population.
Journal of Science and Medicine in Sport, 2018
Objective: Unlike physiological loads, the biomechanical loads of training in running-based sports are still largely unexplored. This study, therefore, aimed to assess the validity of estimating ground reaction forces (GRF), as a measure of external whole-body biomechanical loading, from segmental accelerations. Methods: Fifteen team-sport athletes performed accelerations, decelerations, 90° cuts and straight running at different speeds including sprinting. Full-body kinematics and GRF were recorded with a three-dimensional motion capture system and a single force platform respectively. GRF profiles were estimated as the sum of the product of all fifteen segmental masses and accelerations, or a reduced number of segments. Results: Errors for GRF profiles estimated from fifteen segmental accelerations were low (1-2 N•kg-1) for low-speed running, moderate (2-3 N•kg-1) for accelerations, 90° cuts and moderate-speed running, but very high (>4 N•kg-1) for decelerations and high-speed running. Similarly, impulse (2.3-11.1%), impact peak (9.2-28.5%) and loading rate (20.1-42.8%) errors varied across tasks. Moreover, mean errors increased from 3.26±1.72 N•kg-1 to 6.76±3.62 N•kg-1 across tasks when the number of segments was reduced. Conclusions: Accuracy of estimated GRF profiles and loading characteristics was dependent on task, and errors substantially increased when the number of segments was reduced. Using a direct mechanical approach to estimate GRF from segmental accelerations is thus unlikely to be a valid method to assess whole-body biomechanical loading across different dynamic and high-intensity activities. Researchers and practitioners should, therefore, be very cautious when interpreting accelerations from one or several segments, as these are unlikely to accurately represent external whole-body biomechanical loads.
Measurement in Physical Education and Exercise Science, 2004
In this pilot study of 16 children, we evaluated the reliability and validity of three accelerometers (Mini-Motionlogger [MML], Computer Science Applications, Inc. Actigraph [CSA], and BioTrainer) as indicators of energy expenditure and vertical ground reaction force. The children wore 2 of each type of monitor while they walked, ran, and performed 2 jumping tasks on a force plate and walked, jogged, and ran on a treadmill. Intrainstrument reliability of the monitors ranged from .64 to .98 across the treadmill tasks and from .69 to .98 across the force plate tasks, with the MML and CSA appearing more consistent than the BioTrainer. Analyses of variance were conducted to compare activity counts with criterion measures (oxygen utilization and force plate scores). All of the monitors generally differentiated among the treadmill tasks, mirroring the change in oxygen utilization. The CSA monitors corresponded more closely to the changes in force plate scores than the BioTrainer or the MML. Simple regression analyses indicated that count scores from all of the monitors were associated with oxygen utilization, with the MML and CSA exhibiting stronger relations (R values = .81 and MEASUREMENT .83, respectively) than the BioTrainer (R= .60). Similar analyses between the activity monitors and the force plate scores were also significant but the relations were not as strong as for oxygen utilization (R values = .46, .51, and .52, respectively). Based on backward elimination regression analyses, caloric expenditure on the treadmill tasks was predicted significantly with each of the MML (37 and 38% of variance) and CSA (39 and 42% of variance) units when body mass was included in the model. For the BioTrainer counts to provide the best prediction of caloric expenditure, both body mass and height were retained in the model, resulting in 20 and 25% explained variance. Future research to evaluate the utility of accelerometers should employ tasks that prevent the confounding of force and caloric expenditure.
Journal of science and medicine in sport, 2017
The use of microsensor technologies to conduct research and implement interventions in sports and exercise medicine has increased recently. The objective of this paper was to determine the validity and reliability of the ViPerform as a measure of load compared to vertical ground reaction force (GRF) as measured by force plates. Absolute reliability assessment, with concurrent validity. 10 professional triathletes ran 10 trials over force plates with the ViPerform mounted on the mid portion of the medial tibia. Calculated vertical ground reaction force data from the ViPerform was matched to the same stride on the force plate. Bland-Altman (BA) plot of comparative measure of agreement was used to assess the relationship between the calculated load from the accelerometer and the force plates. Reliability was calculated by intra-class correlation coefficients (ICC) with 95% confidence intervals. BA plot indicates minimal agreement between the measures derived from the force plate and Vi...