The Interday Reliability of Ankle, Knee, Leg, and Vertical Musculoskeletal Stiffness During Hopping and Overground Running

Abstract

A number of methods are used to measure lower extremity musculoskeletal stiffness, but there is a paucity of research examining the reliability of these techniques. Therefore, we investigated the reliability of vertical, leg, knee, and ankle stiffness during overground running and hopping in 20 active men. Participants were required to run on a 10 m overground runway at 3.83 m/s (actual; 3.35 ± 0.12 m/s) and to hop in place at 2.2 Hz (actual; 2.37 ± 0.03 Hz), and at a self-selected frequency (actual; 2.05 ± 0.12 Hz) and at 2.2 Hz (actual; 2.39 ± 0.04 Hz). Reliability was determined using the intraclass correlation coefficient, coefficient of variation, mean differences, and Cohen’s effect sizes. There was good reliability for vertical stiffness, moderate reliability for leg stiffness, and poor reliability for knee and ankle stiffness during the running task. Similar results were observed during the 2.2 Hz hopping tasks, with good reliability displayed for vertical stiffness and poor reliability for ankle and knee stiffness. In conclusion, our results suggest that vertical stiffness is a reliable measure when running at 3.83 m/s and hopping at 2.2 Hz.

A comparison of methods to determine bilateral asymmetries in vertical leg stiffness

“…K vert is a direct function of vGRF and negative COM displacement during the ground contact phase of the hop or jump (Hobara et al, 2014;Joseph et al, 2013). Asymmetries in K vert are therefore a consequence of asymmetries in vGRF and/or negative COM displacement.…”

“…One potential issue with hopping tasks is that they are typically performed at set hopping frequencies and are inherently submaximal in nature (Hobara et al, 2014;Joseph et al, 2013). As such, bilateral hopping tasks may demonstrate greater correspondence to submaximal cyclic performances, such as endurance running, rather than short-term maximal performances, such as jumping.…”

“…During hopping tasks, individuals are required to perform an uninterrupted sequence of repeated bilateral jumps on a force plate. Measurements of vertical ground reaction force (vGRF) and negative displacement of the COM are recorded and K vert is subsequently calculated (Hobara et al, 2014;Joseph et al, 2013). Hopping tasks have been shown to differentiate between certain groups, for example, it has been demonstrated that power-trained athletes exhibit greater K vert than endurance-trained athletes (Hobara et al, 2008) and that endurance-trained athletes exhibit greater K vert than untrained individuals (Hobara et al, 2010).…”

“…Whilst it is important to note that the latter hypothesis has not been properly explored, it is clear that the measurement and quantification of K vert asymmetry is of important practical relevance to athletic performance. K vert may be assessed during a variety of performance tasks, including running (Coleman, Cannavan, Horne, & Blazevich, 2012) and drop jumping (Arampatzis, Schade, Walsh, & Brüggemann, 2001), but is most commonly assessed during the performance of a bilateral 'hopping' task (Hobara, Inoue, Kobayashi, & Ogata, 2014;Joseph, Bradshaw, Kemp, & Clark, 2013). During hopping tasks, individuals are required to perform an uninterrupted sequence of repeated bilateral jumps on a force plate.…”

The Relationship Between Core Stability and Leg Stiffness in Male and Female Athletes

“…Bilateral hopping test with frequency of 2.2 Hz, one of the most reliable tests to assess the leg stiffness [18], was used in this study. The participants were instructed to hop vertically and land on a take-off point with fully extended joints.…”