Abstract
Wearables for player monitoring have become common in collegiate and professional sports. Teams utilize wearable technology to gather volume and intensity data from practice and games throughout a season. Wearable data can be used as an objective marker to indicate when an athlete has met or exceeded a volume threshold. Inaccurate data could lead to improper modifications in training that could negatively impact player performance during a season. A frequently used metric to monitor athletes is jump height; however, like many other metrics calculated by player monitoring wearables, the validity is unknown. PURPOSE: To test the validity of jump height using a basketball and volleyball specific wearable to the gold standard of motion capture. METHODS: Fifteen, physically active young adults (21.3 ± 0.61yrs, 169 ± 10.1cm, 67 ± 17.3kgs), completed 2 visits within 2 weeks of each other. On visit one, following a warmup, an individual max jump height was determined by a Vertec. Once the max jump height was determined, three ranges (45-55%, 75-85% & 95-105% of max jump height) were calculated. During both visits, participants warmed up and were asked to wear a basketball and volleyball-specific wearable (Kinexon Perform IMU, KINEXON Sports, Chicago, IL) in a pocket sewn into the waistband of shorts and another in a belt situated around waist level. In addition, motion capture markers were placed on their feet, thorax, and back and were recorded at 1200 Hz. Participants were asked to complete a minimum of 5 jumps for each jump height range. Jump height ranges were randomized, and ample rest was provided between jumps. Jump heights were calculated by Kinexon software and exported. Jump heights from motion capture were calculated by using a marker at T12 or sternal notch by subtracting the peak height of the jump from the starting height of the marker. Bland-Altman plots were used to measure agreement between the wearable technology and the gold standard. Bias and 95% confidence interval were recorded. RESULTS: Jump height from the wearable in the shorts and belt had a near similar bias of 2 inches below the motion capture height. Specifically, jump height from the wearables in the shorts was: 1.98 ± 0.78, 2.07 ± 0.80, 2.37 ± 0.82 inches, respectively for 50, 80, 100% max jump height, compared to motion capture. Similarly at the belt, wearable jump height bias compared to the motion capture was: 2 ± 0.66, 2.08 ± 0.85, 2.13 ± 0.96 inches, respectively for 50, 80, 100% max jump height. CONCLUSION: Overall, the wearables underestimated jumps by about 2 inches. As the jump ranges get closer to maximum jump height, there was a trend that the underestimation became slightly greater. The implication of an underestimated jump height for athlete monitoring is the inability to compare it to other performance monitoring metrics from force plates or Vertec also routinely used by sports scientists and strength and conditioning coaches. Future studies should investigate assessing the reliability of wearables. If the wearable is highly reliable, this may minimize the need for absolute accuracy if the wearable is worn and used in the same manner every time.
Recommended Citation
Smith, Drew J.; Chen, Kuan; Mann, James B.; and Yentes, Jennifer M.
(2025)
"Validity of Jump Height Using an Athlete Monitoring Wearable,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
Iss.
17, Article 192.
Available at:
https://digitalcommons.wku.edu/ijesab/vol2/iss17/192
