Accuracy of an Experimental Accelerometer for Assessing Countermovement Vertical Jump Height

Abstract

While force plate technology is the gold standard for assessment of many aspects of vertical jump performance, its cost is prohibitive to a broad spectrum of the population. Accelerometry may be more practical, inexpensive, and provide a simple solution that allows hands-on practitioners to readily assess vertical jump performance acutely and over time. Thus, the purpose of this study was to examine the accuracy of an experimental accelerometer for testing vertical jump heights derived from flight times when compared to a laboratory-based force plate system as a criterion measure. Fifteen subjects performed three sets of three nonconsecutive maximal countermovement vertical jumps while standing on the force plate. The accelerometer device sampling at 100 Hz was placed on the anterior abdomen immediately inferior to the umbilicus and secured with an elastic band. Both devices recorded the data simultaneously. The experimental accelerometer was an appropriate tool for the assessment of vertical jump height; however, it significantly overestimated actual vertical jump heights by an average of 3.1 cm. This consistent discrepancy in the measurement may be easily fixed by a simple algorithm correction and should not present an issue in the practical setting where ease of use and the ability to provide immediate feedback regarding an athlete’s performance is of critical importance.

Impact of the Anatomical Accelerometer Placement on Vertical Jump Performance Characteristics

“…The AB accelerometer placement significantly overestimated VJH during countermovement vertical jump with no arm swing, while no differences were observed for the remaining anatomical locations (CH, HP, and UB). Similar observations were made by Cabarkapa et al [16] who found that the accelerometer device placed 3 cm above the umbilicus (i.e., anterior abdomen) tended to overestimate VJH by approximately 3.1 cm during a countermovement vertical jump with no arm swing when compared to the force plate as a gold standard testing modality. The observed similarities may be attributed to researchers using the same accelerometer technology (StriveTech) for VJH assessment as well as similar anatomical placement (i.e., 5 cm vs. 3 cm inferior to the umbilicus).…”

“…Ground reaction force curves were computed from raw vertical acceleration data by adding acceleration due to gravity (9.81 m•s −2 ) and multiplying the resultant value with the subject's body mass, from which the following dependent variables were derived: peak concentric force (PCF; highest value observed during the concentric phase of the jumping motion), peak landing force (PLF; highest value observed during the landing phase of the jumping motion), and vertical jump height (VJH; i.e., calculated based on the flight time using the following equation [14,16]; (t 2 •g)/8; g = 9.81 m•s −2 , t = time in the air (sec)-determined as a change in the time between the first and last time point when the ground reaction force curve crosses zero value. The same dependent variables were obtained from the force plate system software (VALD, Force Decks Max, Brisbane, Australia).…”

“…Thus, to help strength and conditioning professionals and sports scientists efficiently administer vertical jump assessments on the field, different portable devices such as contact mats, optical timing systems, and accelerometers have often been implemented [10][11][12][13][14]. A considerable amount of scientific literature has examined the validity and reliability of various accelerometer-based technologies for the assessment of vertical jump performance characteristics and has reported mixed findings [10,11,[13][14][15][16][17][18][19]. In a recently published study, Cabarkapa et al [16] found that an innovative accelerometer device (StriveTech) was an acceptable testing modality for the assessment of vertical jump height, despite the tendency to overestimate measurements by approximately 3.1 cm when compared to the laboratory-based force plate system as a criterion measure.…”

“…A considerable amount of scientific literature has examined the validity and reliability of various accelerometer-based technologies for the assessment of vertical jump performance characteristics and has reported mixed findings [10,11,[13][14][15][16][17][18][19]. In a recently published study, Cabarkapa et al [16] found that an innovative accelerometer device (StriveTech) was an acceptable testing modality for the assessment of vertical jump height, despite the tendency to overestimate measurements by approximately 3.1 cm when compared to the laboratory-based force plate system as a criterion measure. Similarly, the Myotest accelerometer was shown to overestimate vertical jump height by 8.0 cm and flight time by 6.4% when compared to the force plate [11,19].…”