INVESTIGATING THE RELATIONSHIP BETWEEN BALANCE ASSESSMENT AND CENTRE OF PRESSURE EXCURSION DURING GOLF PUTTING

The aim of this study was to investigate the relationship between balance assessment and centre of pressure (COP) excursion during golf putting between recreational and novice female golfers. Five novice golfers (age: 28.0±15.8 years) and six recreational golfers (age: 29.0 ± 19.2 years; handicap: 21.4 ± 10.9 strokes) participated in the study. All participants performed the Star Excursion Balance Test (SEBT) and had their COP measured on a force plate while putting a ball towards targets. Significant differences were found between recreational and novice conditions for the COP displacement and velocity excursions (p0.05).Models for predictors of the COP excursions were identified mainly in the anteroposterior direction for the first 50% of the time to complete the putting stroke. The results suggest that SEBT may complement balance assessment for coaches in golf putting

THE EFFICACY OF VIDEO-BASED MARKER-LESS TRACKING SYSTEM IN GAIT ANALYSIS

An alternative to the 3D motion capture is the marker-less 3D video tracking system. Though not rigorously tested yet, the 3D marker less video tracker would break new grounds if it is possible of extracting similar kinematic parameters as the gold standard 3D marker based motion capturers. The aim of our study is to explore the feasibility of a video based marker-less system which is as accurate and precise as its marker based counterpart. A series of gait analysis tests were carried out on ten subjects with a marker and marker-less system simultaneously. The study suggests potential applications in gait analysis in the academic classrooms and clinical settings where observations of anatomical motions provide meaningful feedback

VIDEO-BASED MARKER-LESS TRACKING SYSTEM IN GAIT ANALYSIS

An alternative to the 30 motion marker-based optical camera capture is the Star Tracker 3D, a marker-less video-based tracking system. The aim of our study is to investigate the efficacy of the Star Tracker 3D. A series of gait analysis tests were carried out on ten subjects with a marker and marker-less tracking system simultaneously. The study suggests potential application in gait analysis in the academic classrooms and clinical settings where observations of anatomical motions can provide meaningful feedback

THE EFFICACY OF VIDEO-BASED MARKER-LESS TRACKING SYSTEM IN GAIT ANALYSIS

An alternative to the 3D motion capture is the marker-less 3D video tracking system. Though not rigorously tested yet, the 3D marker-less video tracker would break new grounds if it is possible of extracting similar kinematic parameters as the gold standard 3D marker based motion capturers. The aim of our study is to explore the feasibility of a video based marker-less system. A series of gait analysis tests were carried out on ten subjects with a marker and marker-less system simultaneously. The study suggests potential applications in gait analysis in the academic classrooms and clinical settings where observations of anatomical motions provide meaningful feedback

ESTIMATING LOWER LIMB JOINT MOMENTS IN GAIT USING COMMON MACHINE LEARNING APPROACHES

The aim of this study was to investigate the efficacy of common machine learning algorithmic approaches to estimate lower limb joint moments during fast walking gait. Kinematic and ground reaction force data on 19 participants were captured with a force-plate and motion caption capture system. Inverse dynamics was used to calculate the right lower limb joint moments and common machine learning algorithmic approaches, such as Random Forest (RF), Linear Regression (LR), Neural Network (NN), AdaBoost (AB) and Gradient Boosting, were used to predict the corresponding joint moments using only the kinematic data. High coefficient of determination values (R2\u3e0.9) for predicting moments using random forest, neural network and AdaBoost are observed in for the ankle, knee and hip joints in frontal, sagittal and transverse planes. The other approaches had R2 values between ranged 0.71 and 0.97. This suggests that common machine learning algorithms may be a feasible approach to estimate joint moments during fast walking in a clinical setting for monitoring sport injury prevention and management

INVESTIGATING THE RELATIONSHIP BETWEEN JOINT COUPLING COORDINATION AND MUSCLE ACTIVITY DURING WALKING

The study aimed to investigate the relationship between joint coupling coordination and muscle activity of the lower limb during normal gait in shod and barefoot walking. Ten healthy participants served in this study. We assessed joint coordination and muscle activity while the participants walked on a treadmill at their self-selected speed in shod and barefoot conditions. T-tests were used to determine the differences between walking conditions in the early, mid and late phases of support. A cross-correlation analysis was used to determine the similarity between the coordination angle and EMG profiles in the three phases of support. The study suggested no differences between shod and barefoot coordination. The correlation coefficients were moderately high (r=0.6) for both shod and barefoot. It was concluded that the rearfoot/tibia coordination may be under passive rather than active control

KAJIAN KONDISI STOK IKAN SELAR (Selar crumenophthalmus) DI PERAIRAN SERAM BARAT, MALUKU

Selar fish is a potential small pelagic fishery resource in Indonesian territorial waters and is located in Maluku Province, it specially in west seram waters. This research was carried out in the waters of West Seram, Maluku, from March 2018 to February 2019. The objective of research was to study the stock condition of bigeye scad, Selar crumenophthalmus, based on population dynamic from length frequency distribution. Fish samples were collected every month at fish landing from lift net fishers. Totally, there were 1890 individuals collected during the study, excepted June, composed of 925 males and 965 females with the length size ranging from 13.3 cm to 27.2 cm which was composed of 2 and 3 cohorts every month. Condition stock of bigeye scad based on yield per recruit analysis showed that the stock was still below the level of MSY (0.03 of 0.047), obtained from L∞ was 27.40 cm, K was 1.55/yr, Z was 3.66/yr, M was 2.51/yr, F was 1.15/yr, E was 0.32/yr, Lc was 19.92 cm and t0 was -0.10 /yr. This shows that the higher Lc value of selar fish in west seram waters more selective and otherwise.Ikan selar adalah sumberdaya perikanan pelagis kecil yang potensial di perairan teritorial Indonesia dan berada di Provinsi Maluku, khususnya di perairan Seram Barat. Penelitian ini dilakukan di perairan Seram Barat, Maluku, dari bulan Maret 2018 sampai Februari 2019. Tujuan penelitian ini adalah mempelajari kondisi stok ikan Selar (Selar crumenopththalmus) didasarkan pada dinamika populasi dari distribusi frekuensi panjang. Contoh ikan dikoleksi tiap bulan di tempat pendaratan dari nelayan lift net. Total 1890 individu dikoleksi selama penelitian kecuali bulan Juni yang terdiri dari 925 jantan dan 965 betina dengan panjang berkisar dari 13,3 cm sampai 27,2 cm yang terdiri dari 2 dan 3 kelompok umur tiap bulan. Kondisi stok ikan selar didasarkan pada analisis hasil per penambahan individu baru menunjukkan bahwa stok masih di bawah tingkat MSY (0,03 dari 0,047) yang diperoleh dari L∞= 27,40 cm, K= 1,55/yr, Z= 3,66/tahun, M= 2,51/tahun, F= 1,15/tahun, E= 0,32/tahun, Lc (panjang utk pertama kali tertangkap)= 19,92 cm and t0= -0,10/ yr. Hal ini menunjukkan bahwa semakin tinggi nilai Lc ikan selar di Perairan Seram Barat akan semakin selektif dan sebaliknya

JOINT LOADING WHILE PERFORMING A SIDE-STEP CUTTING MANOUEVRE ON ARTlClAL GRASS TURF WITH DIFFERENT INFILL DEPTHS

The aim of this study was to determine differences in the joint loadings when performing side-step action on artificial grass turf with different infill depths. Significant changes in the ankle inversion angle (Ankle angle Y; p=0.01; ES=0.73), ankle inversion/eversion moment (Ankle moment Y; p=0.03; ES=0.54) and ankle abduction-adduction moment (Anklemoment Z; p=0.01; ES=0.76) at GRFSeak suggests greater loadings, in particular, at the ankle jint when performing the side-step manoeuvres on artificial grass turfs with thicker infill depths; indicating that all of the lower extremity adaptations to execute the stepside occurs at the ankle rather than the knee. A change in infill depths will cause the body posture to adopt a change in technique when executing the side-step manoeuvre. It is possible that greater joint moments elicited could be of risk to the athletes

DIFFERENCES IN GROUND REACTION FORCES WHEN PERFORMING THE SIDE-STEP CUTTING ACTION ON DIFFERENT INFILL DEPTHS

This study aimed to quantify differences in ground reaction forces (GRFs) when performing a side-step cutting action on artificial grass turf with two different infill depths. GRFXPeak (7.27 ± 2.7 N/kg vs. 9.00 ± 2.7 N/kg, p=0.00) and GRFYPeak (5.41 N/kg ± 1.4 vs. 6.15 N/kg ± 1.6, p=0.00) were significantly larger, but not GRFZPeak (28.26 N/kg ± 8.6 vs. 29.64 N/kg ± 9.3, p=0.58) when participants (n=17) performed side-steps on turf with greater infill depths. Larger GRFZPeak during heel-strike may be due to larger knee extension angle (39.7 deg ± 8.2 vs. 34.7 deg ± 8.5, p=0.03) while significantly larger GRFXPeak and GRFYPeak at the weight acceptance phase and push-off phase may be due to a larger knee extension angle in conjunction with the hardness of sand/rubber infills given the increased thickness as well as frictional components of the artificial grass turfs