Ahmad Faizal Salleh

Track Cyclist Performance Monitoring System Using Wireless Sensor Network

The right training programs are an important factor to increase the cycling performance among the professional track cyclist. Over the years, the cyclist performance was based on the feedback from bicycle’s kinematics and physiological condition. The advancement in sensor technologies allows the optimization of the training program; by combining both information from the cyclist’s physiological condition and kinematic data from the bicycle. The physiological conditions such as heart rate variability (HRV) and forehead temperate can be combined with bicycle kinematic data such as speed and distance to provide accurate assessment of the track cyclist’s condition and training program intensity. A system that combines data from physiological signal and bicycle kinematic has been developed for this purpose. Wearable physiological body sensors and bicycle kinematic sensors are deployed using wireless sensor network (WSN). HRV provide using photoplethysmography (PPG) technique that capture signal from cyclist’s finger, which provide 3 % error rate refer to heart rate belt. Data handling and communication was developed based on Zigbee protocol whereby the WSN centralized base-station was supported by two repeater node which was used to extend signal coverage in Velodrome to prevent data losses. With two repeater nodes and adjustment on the routing protocol, the packet drops were reduced from 46 to 3 %. The propagation study was carried out in the Velodrome with environment temperature range from 28 to 30 °C and humidity was observed at 85 %. The optimization of network topology by considering the connectivity among the wireless nodes is crucial in order to reduce data losses.

Leg Length Discrepancy: Dynamic Balance Response during Gait

Balance in the human bodys movement is generally associated with different synergistic pathologies. The trunk is supported by ones leg most of the time when walking. A person with poor balance may face limitation when performing their physical activities on a daily basis, and they may be more prone to having risk of fall. The ground reaction forces (GRFs), centre of pressure (COP), and centre of mass (COM) in quite standing posture were often measured for the evaluation of balance. Currently, there is still no experimental evidence or study on leg length discrepancy (LLD) during walking. Analysis of the stability parameters is more representative of the functional activity undergone by the person who has a LLD. Therefore, this study hopes to shed new light on the effects of LLD on the dynamic stability associated with VGRF, COP, and COM during walking. Eighteen healthy subjects were selected among the university population with normal BMIs. Each subject was asked to walk with 1.0 to 2.0 ms−1 of walking speed for three to five trials each. Insoles of 0.5 cm thickness were added, and the thickness of the insoles was subsequently raised until 4 cm and placed under the right foot as we simulated LLD. The captured data obtained from a force plate and motion analysis present Peak VGRF (single-leg stance) and WD (double-leg stance) that showed more forces exerted on the short leg rather than long leg. Obviously, changes occurred on the displacement of COM trajectories in the ML and vertical directions as LLD increased at the whole gait cycle. Displacement of COP trajectories demonstrated that more distribution was on the short leg rather than on the long leg. The root mean square (RMS) of COP-COM distance showed, obviously, changes only in ML direction with the value at 3 cm and 3.5 cm. The cutoff value via receiver operating characteristic (ROC) indicates the significant differences starting at the level 2.5 cm up to 4 cm in long and short legs for both AP and ML directions. The present study performed included all the proposed parameters on the effect of dynamic stability on LLD during walking and thus helps to determine and evaluate the balance pattern.

Real-time track cycling performance prediction using ANFIS system

ABSTRACT The next stage performance evaluation of an athlete can be predicted by implementing Artificial Intelligence technique. In track cycling event, coach and sports physician are concerned with the performance of the cyclist. The performance prediction may help to fine-tune the cyclist training intensities and strategies planning. This study was conducted to fulfil the prediction requirement by adopting a Fuzzy Inference System to classify the cyclist current cycling performance state. The six levels of output classification by a Fuzzy Inference System are to indicate the athlete’s current state performance using the body temperature, heart rate variability and speed as input parameters. An Adaptive Neuro-Fuzzy Inference System was applied to predict the cycling speed that can be achieved in the next lap. Using Adaptive Neuro-Fuzzy Inference System method, the average speed for the next laps can be predicted and compared with the actual speed. The regression value with r = 0.9029 indicates the Adaptive Neuro-Fuzzy Inference System is an adequate prediction algorithm to evaluate the cyclist performance. The predicted time to complete compared favourably with the actual finishing time with a ± 13.6% average error. Hence, the developed system is reliable and suitable for sports events that deal with speed and time.

The Effects of Leg Length Discrepancy on Stability and Kinematics-Kinetics Deviations: A Systematic Review

Various studies have examined body posture stability, including postural sway and associated biomechanical parameters, to assess the severity effects of leg length discrepancy (LLD). However, various viewpoints have been articulated on the results of these studies because of certain drawbacks in the comprehensive analysis of the effect of variations in LLD magnitude. Therefore, this systematic review was performed to help focus on the current findings to help identify which biomechanical parameters are most relevant, commonly used, and able to distinguish and/or have specific clinical relevance to the effect of variations in LLD magnitude during static (standing) and dynamic (walking) conditions. Several electronic databases containing studies from the year 1983 to 2016 (Scopus, ScienceDirect, PubMed, PMC, and ProQuest) were obtained in our literature search. The search process yielded 22 published articles that fulfilled our criteria. We found most of the published data that we analyzed to be inconsistent, and very little data was obtained on the correlation between LLD severity and changes in body posture stability during standing and walking. However, the results of the present review study are in line with previous observational studies, which describe asymmetry in the lower limbs corresponding to biomechanical parameters such as gait kinematics, kinetics, and other parameters described during static (standing) postural balance. In future investigations, we believe that it might be useful to use and exploit other balance-related factors that may potentially influence body posture stability.

Finite element modelling of Plantar Fascia response during running on different surface types

Plantar fascia is a ligament found in human foot structure located beneath the skin of human foot that functioning to stabilize longitudinal arch of human foot during standing and normal gait. To perform direct experiment on plantar fascia seems very difficult since the structure located underneath the soft tissue. The aim of this study is to develop a finite element (FE) model of foot with plantar fascia and investigate the effect of the surface hardness on biomechanical response of plantar fascia during running. The plantar fascia model was developed using Solidworks 2015 according to the bone structure of foot model that was obtained from Turbosquid database. Boundary conditions were set out based on the data obtained from experiment of ground reaction force response during running on different surface hardness. The finite element analysis was performed using Ansys 14. The results found that the peak of stress and strain distribution were occur on the insertion of plantar fascia to bone especially on calcaneal area. Plantar fascia became stiffer with increment of Youngs modulus value and was able to resist more loads. Strain of plantar fascia was decreased when Youngs modulus increased with the same amount of loading.

Analysis of crack propagation in human long bone by using finite element modeling

The aim of this research is to present a numerical modeling of crack for human long bone specifically on femur shaft bone under mode I loading condition. Two – dimensional model (2D) of long bone was developed based on past research study. The finite element analysis and construction of the model are done using Mechanical APDL (ANSYS) v14.0 software. The research was conducted mainly based on two conditions that were at different crack lengths and different loading forces for male and female. In order to evaluate the stress intensity factor (KI) of the femur shaft of long bone, this research employed finite element method to predict the brittle fracture loading by using three-point bending test. The result of numerical test found that the crack was formed when the crack length reached 0.0022 m where KI values are proportional with the crack’s length. Also, various loading forces in range of 400 N to 1000 N were applied in an attempt to study their effect on stress intensity factor and it was found that th...

Effect of leg length inequality on body weight distribution during walking with load: A pilot study

This paper presents a pilot study on the effect of leg length inequality (LLI) on the body weight distribution. Plywood block was used to mimic the artificial LLI. The height of the plywood was increased up to 4.0 cm with 0.5 cm increment. Hence, eight different height of LLI was considered in order to investigate which height of LLI initiated the significant effect. The experiment was conducted on a healthy subject that walking on the force plate in two conditions; with a load of 2 kg (carried by a backpack worn by the subject) and without load. Qualisys Track Manager (QTM) system was employed for data processing. The results showed that the short leg subjected to more weight compared to the long leg during walking with inequality of leg length especially when carrying additional load.

Clinical effects of leg length discrepancy through ground and joint reaction force responses: A review

Leg length discrepancy (LLD) is caused either due to functional disorder or shortening of bone structure. This disorder could contribute to the significant effects on body weight distribution and lumbar scoliosis at the certain extend. Ground reaction force and joint reaction force are the parameters that can be used to analyze the responses in weight distribution and kinetics changes on the body joints, respectively. Hence, the purpose of this paper is to review the studies that focus on the clinical effects of LLD to the lower limb and spine through ground and joint reaction force responses that could lead to the orthopedics disorder.

Finite element analysis of cortical bone fracture in human thigh segment

Stress intensity factor, K and strain energy release rate, G have been obtained by using three point bending test in two-dimensional (2D) model of cortical bone in human thigh segment. The test is done in finite element analysis (FEA) with respect to continuum mechanics approach. The K and G values from the simulation gave almost similar values compared by using an equation established by A. F. Bower. The maximum error was 7.2 % while the minimum was only 1.2 %. From the graph obtained, the K and G values were increased when the ration of crack length and width, a/W of the model increased. In can also be proven that K is proportional to G in linear elastic Mode I model. There is lack of study in continuum mechanics area concerned on the use of numerical analysis of initiation and propagation cracks in human cortical bone. Thus, by using a finite element analysis or conceptual model when attempting to reduce the risk of injury and designing better devices on medical purposes serve as a logical starting point.

Kinematics of Foot during Running: A Review

Running can be considered as an important movement since it can be categorized as one of daily activities. However, running movement may contribute to injuries for example, subject to plantar fasciitis. The objective of this review is to summarize the information of published articles related to kinematics aspect, which is one of key factors that can cause injury in running movement. The search strategy was carried out from Science Direct database. The variability of methodological protocol due to different running mode and condition influenced the foot kinematics which has been proved by the findings from the experiments. In future, research on investigating the suitable speed and condition to standardized running methodological protocol should be done in order to obtain a reliable result.