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

Combining Sound and Deep Neural Networks for the Measurement of Jump Height in Sports Science

Jump height tests are employed to measure lower-limb muscle power of athletic and non-athletic populations. The most popular instruments for this purpose are jump mats and, in recent years, smartphone apps, which compute jump height through the manual annotation of video recordings and recently automatically using the sound produced during the jump to extract the flight time. In a previous work, the afore-mentioned sound systems were presented by the authors in which the take-off and landing events from the audio recordings of jump executions were obtained using classical signal processing. In this work, a more precise, noise-immune, and robust system, capable of working in the most unfavorable environments, is presented. The system uses a deep neural network trained specifically for this purpose. More than 300 jumps were recorded to train and validate the network performance. The ground truth was a jump mat, providing a slightly better accuracy in quiet and medium quiet environments but excellent accuracy in noisy and complicated ones. The developed audio-based system is a trustworthy instrument for measuring jump height accurately in any kind of environment, providing a perfect measurement tool that can be accessed through a mobile phone in the form of an app.

Bipedal hopping as a new measure to detect subtle sensorimotor impairment in people with multiple sclerosis

BACKGROUND

Bipedal hopping has the potential to detect subtle multiple sclerosis (MS)-related impairments, especially among patients who "pass" typical movement tests. In this narrative review, we outline the biomechanics of bipedal hopping and propose its usefulness as a novel outcome measure for people with MS having mild disability.

METHODS

We summarize articles that (1) examined the biomechanics of jumping or hopping and (2) tested the validity and/or reliability of hopping tests. We consolidated consistencies and gaps in research and opportunities for future development of the bipedal hop test.

RESULTS

Bipedal hopping requires immense power, coordination, balance, and ability to reduce co-contraction; movement components typically affected by MS. These impairments can be measured and differentiated by examining specific variables, such as hop length (power), symmetry (coordination), center of pressure (balance), and coefficient of variability (co-contraction/spasticity). Bipedal hopping challenges these aspects of movement and exposes sensorimotor impairments that may not have been apparent during walking.

CONCLUSIONS

Testing of bipedal hopping on an instrumented walkway may detect and monitor sensorimotor control in people with MS who do not currently present with clinical deficits. Early measurement is imperative for precise rehabilitation prescription to slow disability progression prior to onset of measurable gait impairment.Implications for rehabilitationJumping and hopping tests detect lower limb and balance impairments in children, athletes, and older adults.Bipedal hop test measures multiple domains: power, coordination, balance, and muscle timing.Bipedal hop test may expose subtle sensorimotor impairments in people with multiple sclerosis.Multiple variables measured can discern type of sensorimotor impairment to direct personalized rehabilitation programs.