Measurement of bend sprinting kinematics with three-dimensional motion capture: a test–retest reliability study

Abstract

Sprint velocity decreases on the bend when compared with the straight, therefore understanding technique during bend sprinting could have important implications for aiding race performance. Few bend sprinting studies have used optoelectronic cameras to investigate kinematic variables. Limited published evidence regarding the reliability of marker sets in conditions representative of elite bend sprinting makes model selection difficult. Therefore, a test-retest protocol was conducted to establish the reliability and minimum detectable difference of a lower limb and trunk marker set during bend sprinting (radius: 36.5 m). Six participants completed five, 60 m trials at maximum effort, with data collected at 38-45 m. This was repeated 2-7 days later. Spatio-temporal (e.g. contact time) and kinematic variables (e.g. peak joint angles) were evaluated. Intraclass correlation coefficients (ICC) were used to determine the between-and within-day reliability. Between-day reliability (ICC 3, k) was fair to excellent for all variables. Compared to between-day, within-day reliability demonstrated stronger agreement for the majority of variables. Thus, same-day data collection is preferable. It has been established that the marker set is reliable for future use. In addition, the minimal detectable difference was calculated which serves as useful reference for future research in bend sprinting. (Word count: 200)

Three-dimensional data-tracking simulations of sprinting using a direct collocation optimal control approach

“…We were surprised by this result, as we anticipated the kinematics tracking errors from the validation simulation to be more evenly distributed amongst all the DOFs and higher than those obtained from the equivalent sprinting phase trial of the calibration simulations. In any case, it is worthwhile noting that the smallest detectable difference for peak ankle dorsiflexion during the stance phase of running and bend sprinting is in excess of 10 (Alenezi et al, 2016;Judson et al, 2020), and the largest right ankle dorsiflexion difference we obtained during the stance phase of the validation simulation was 8.9 . Interpreting these findings together suggests that the right ankle kinematics tracking error obtained is likely within the bounds of biological variation and measurement error.…”

Horizontal force production and multi‐segment foot kinematics during the acceleration phase of bend sprinting

“…Shoe‐mounted markers (posterior, medial, and lateral calcaneus, 1st and 5th metatarsal bases, MTH1, MTH2, MTH5, and head of the 2nd toe) were used to represent the movement of the underlying structure of the foot. Further details of marker placement can be found in Judson et al…”

“…Minimum detectable difference (MDD) indicates the magnitude of change required to be considered “real.” Where the difference between conditions exceeds the MDD, it can be considered a change due to experimental condition and not natural athlete variance or protocol error. Therefore, peak angles and spatiotemporal variables were interpreted with reference to the MDD evaluated in the bend sprinting, identified by Judson et al…”

“…Shoe-mounted markers (posterior, medial, and lateral calcaneus, 1st and 5th metatarsal bases, MTH1, MTH2, MTH5, and head of the 2nd toe) were used to represent the movement of the underlying structure of the foot. Further details of marker placement can be found in Judson et al 17 Kinetic data were collected using a Kistler force plate (Model: 9287BA, 900 × 600 mm) sampling at 1000 Hz. The force plate was embedded into the track surface and covered with a secured piece of synthetic track.…”

Kinematic modifications of the lower limb during the acceleration phase of bend sprinting

“…A modified Vicon Plug in Gait (PiG) marker set (lower limb and trunk; Judson, Churchill, Barnes, Stone, & Wheat (2017)) was used to model the torso, pelvis, thighs, shanks and foot segments (toebox, forefoot, rearfoot). For full details of marker locations please see (Judson et al, 2018). The marker set was applied by the same researcher for all participants.…”