High speed cameras for motion analysis in sports science

Jumping mechanics have been investigated at take-off, flight and landing, mainly in reference to the limbs with limited evaluation of the thoracolumbosacral region. The objectives of this study were to investigate head, neck, thoracolumbosacral and limb angles in a group of experienced showjumping horses (competing at 1.20-1.60 m) over an upright and parallel spread fence. Ten horses in active showjumping training were recruited (mean 8 years old). High-speed videography (240 Hz) was used to determine thoracolumbosacral kinematic variables of the approach and take-off. No significant differences between the upright and parallel spread fences were observed for any of the variables measured. Individual horse review showed that neck-trunk, thoracolumbar, lumbosacral, coxofemoral angles, take-off distance and speed patterns at take-off were consistent among horses and also repeatable between fence types. Head-neck, stifle and tarsal angles had great variability among horses. The main limitation of this study was that only 2D motion analysis was carried out. In conclusion, analysis of individual horse patterns showed that head, neck, back and limb angles were repeatable over submaximal upright and spread fences in ten horses. Some angles were consistent among horses, but others had individual horse variation.

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Audio-Based System for Automatic Measurement of Jump Height in Sports Science

Sensors ◽

10.3390/s19112543 ◽

2019 ◽

Vol 19 (11) ◽

pp. 2543

Author(s):

Basilio Pueo ◽

Jose J. Lopez ◽

Jose M. Jimenez-Olmedo

Keyword(s):

High Speed ◽

Muscle Power ◽

Audio Signal ◽

Automatic Measurement ◽

Flight Time ◽

Systematic Bias ◽

Jump Height ◽

Random Errors ◽

Signal Processing Algorithm ◽

Sports Science

Jump height tests are employed to measure the lower-limb muscle power of athletic and non-athletic populations. The most popular instruments for this purpose are jump mats and, more recently, smartphone apps, which compute jump height through manual annotation of video recordings to extract flight time. This study developed a non-invasive instrument that automatically extracts take-off and landing events from audio recordings of jump executions. An audio signal processing algorithm, specifically developed for this purpose, accurately detects and discriminates the landing and take-off events in real time and computes jump height accordingly. Its temporal resolution theoretically outperforms that of flight-time-based mats (typically 1000 Hz) and high-speed video rates from smartphones (typically 240 fps). A validation study was carried out by comparing 215 jump heights from 43 active athletes, measured simultaneously with the audio-based system and with of a validated, commercial jump mat. The audio-based system produced nearly identical jump heights than the criterion with low and proportional systematic bias and random errors. The developed audio-based system is a trustworthy instrument for accurately measuring jump height that can be readily automated as an app to facilitate its use both in laboratories and in the field.

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Motion Analysis Of Simulated Vehicle-Pedestrian Impacts Using Automated High-Speed Cinephotogrammetry

10.1117/12.936289 ◽

1984 ◽

Cited By ~ 1

Author(s):

Francois Mesqui ◽

Peter Niederer

Keyword(s):

Motion Analysis ◽

High Speed

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Validation of High Speed Motion Analysis System to Measure Maximal Speed

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000385914.26718.1d ◽

2010 ◽

Vol 42 ◽

pp. 686

Author(s):

Nidhi Gupta ◽

Govindasamy Balasekaran ◽

Visvasuresh Victor Govindaswamy

Keyword(s):

Motion Analysis ◽

High Speed ◽

Motion Analysis System ◽

Maximal Speed ◽

Analysis System

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Instrumented Measurements on Radioactive Waste Disposal Containers During Experimental Drop Testing

ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B ◽

10.1115/icem2011-59142 ◽

2011 ◽

Author(s):

Thomas Quercetti ◽

Andre Musolff ◽

Karsten Mu¨ller

Keyword(s):

Radioactive Waste ◽

Motion Analysis ◽

High Speed ◽

Measurement Techniques ◽

Radioactive Waste Disposal ◽

Test Results ◽

Federal Institute ◽

Materials Research ◽

Drop Tests ◽

Main Basis

In context with disposal container safety assessment of containers for radioactive waste the German Federal Institute for Materials Research and Testing (BAM) performed numerous drop tests in the last years. The tests were accompanied by extensive and various measurement techniques especially by instrumented measurements with strain gages and accelerometers. The instrumentation of a specimen is an important tool to evaluate its mechanical behavior during impact. Test results as deceleration-time and strain-time functions constitute a main basis for the validation of assumptions in the safety analysis and for the evaluation of calculations based on finite-element methods. Strain gauges are useful to determine the time dependent magnitude of any deformation and the associated stresses. Accelerometers are widely used for the measuring of motion i.e. speed or the displacement of the rigid cask body, vibration and shock events. In addition high-speed video technique can be used to visualize and analyze the kinematical impact scenario by motion analysis. The paper describes some selected aspects on instrumented measurements and motion analysis in context with low level radioactive waste (LLW) container drop testing.

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Biomechanical assessment of various punching techniques

International Journal of Legal Medicine ◽

10.1007/s00414-020-02440-8 ◽

2020 ◽

Author(s):

Jiri Adamec ◽

Peter Hofer ◽

Stefan Pittner ◽

Fabio Monticelli ◽

Matthias Graw ◽

...

Keyword(s):

High Speed ◽

Vertical Wall ◽

Force Plate ◽

Physical Parameters ◽

Time Curve ◽

Biomechanical Assessment ◽

Sports Science ◽

General Terms ◽

Force Time ◽

The Impact

Abstract Punches without the use of instruments/objects are a common type of body violence and as such a frequent subject of medicolegal analyses. The assessment of the injuries occurred as well as of the potential of the assault to produce severe body harm is based on objective traces (especially the documented injuries of both parties involved) as well as the—often divergent—descriptions of the event. Quantitative data regarding the punching characteristics that could be used for the assessment are rare and originate mostly in sports science. The aim of this study was to provide physical data enabling/facilitating the assessment of various punching techniques. A total of 50 volunteers took part in our study (29 males and 21 females) and performed severe punches with the fist, with the small finger edge of the hand (karate chop), and with the open hand with both the dominant and the non-dominant hands in randomized order. The strikes were performed on a boxing pad attached to a KISTLER force plate (sampling frequency 10,000 Hz) mounted on a vertical wall. The punching velocity was defined as the hand velocity over the last 10 cm prior to the contact to the pad and ascertained by using a high-speed camera (2000 Hz). Apart from the strike velocity, the maximum force, the impulse (the integral of the force-time curve), the impact duration, and the effective mass of the punch (the ratio between the impulse and the strike velocity) were measured/calculated. The results show a various degree of dependence of the physical parameters of the strikes on the punching technique, gender, hand used, body weight, and other factors. On the other hand, a high degree of variability was observed that is likely attributable to individual punching capabilities. In a follow-up study, we plan to compare the “ordinary” persons with highly trained (boxers etc.) individuals. Even though the results must be interpreted with great caution and a direct transfer of the quantitative parameters to real-world situations is in general terms not possible, the study offers valuable insights and a solid basis for a qualified forensic medical/biomechanical assessment.

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New method to evaluate three-dimensional push-off angle during short-track speed skating using wearable inertial measurement unit sensors

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411919831309 ◽

2019 ◽

Vol 233 (4) ◽

pp. 476-480 ◽

Cited By ~ 2

Author(s):

Kyungsoo Kim ◽

Jun Seok Kim ◽

Tserenchimed Purevsuren ◽

Batbayar Khuyagbaatar ◽

SuKyoung Lee ◽

...

Keyword(s):

Motion Analysis ◽

Inertial Measurement Unit ◽

High Speed ◽

Three Dimensional ◽

Analysis Data ◽

New Method ◽

Measurement Unit ◽

Angle Estimation ◽

Inertial Measurement ◽

Speed Skating

The push-off mechanism to generate forward movement in skating has been analyzed by using high-speed cameras and specially designed skates because it is closely related to skater performance. However, using high-speed cameras for such an investigation, it is hard to measure the three-dimensional push-off force, and a skate with strain gauges is difficult to implement in the real competitions. In this study, we provided a new method to evaluate the three-dimensional push-off angle in short-track speed skating based on motion analysis using a wearable motion analysis system with inertial measurement unit sensors to avoid using a special skate or specific equipment insert into the skate for measurement of push-off force. The estimated push-off angle based on motion analysis data was very close to that based on push-off force with a small root mean square difference less than 6% when using the lateral marker in the left leg and the medial marker in the right leg regardless of skating phase. These results indicated that the push-off angle estimation based on motion analysis data using a wearable motion capture system of inertial measurement unit sensors could be acceptable for realistic situations. The proposed method was shown to be feasible during short-track speed skating. This study is meaningful because it can provide a more acceptable push-off angle estimation in real competitive situations.

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