Leg Tissue Mass Composition Affects Tibial Acceleration Response Following Impact

Abstract

To date, there has not been a direct examination of the effect that tissue composition (lean mass/muscle, fat mass, bone mineral content) differences between males and females has on how the tibia responds to impacts similar to those seen during running. To evaluate this, controlled heel impacts were imparted to 36 participants (6 M and 6 F in each of low, medium and high percent body fat [BF] groups) using a human pendulum. A skin-mounted accelerometer medial to the tibial tuberosity was used to determine the tibial response parameters (peak acceleration, acceleration slope and time to peak acceleration). There were no consistent effects of BF or specific tissue masses on the un-normalized tibial response parameters. However, females experienced 25% greater peak acceleration than males. When normalized to lean mass, wobbling mass, and bone mineral content, females experienced 50%, 62% and 70% greater peak acceleration, respectively, per gram of tissue than males. Higher magnitudes of lean mass and bone mass significantly contributed to decreased acceleration responses in general.

Leg soft tissue position and velocity data from skin markers can be obtained with good to acceptable reliability following heel impacts

“…The first set of three trials was applied using a human pendulum (Duquette & Andrews, 2010;Flynn, Holmes, & Andrews, 2004;Lafortune & Lake, 1995;Schinkel-Ivy et al, 2012), with participants securely strapped supine to the pendulum, and the right knee joint space aligned with the leading edge of the pendulum frame. The pendulum was manually pulled back a distance (between 50 and 65 cm) in order to achieve a velocity (linear voltage differential transformer attached to the pendulum; Celesco DV301, Don Mills, ON, Canada) of 1.0-1.15 m · s -1 and a force of 1.8-2.8 times body weight (Cavanagh & Lafortune, 1980;Duquette & Andrews, 2010;Flynn et al, 2004;Holmes & Andrews, 2006; Schinkel-Ivy, Burkhart, & Andrews, 2010).…”

“…However, Burkhart, Schinkel-Ivy, and Andrews (2013) identified a relationship between the soft tissue composition of the distal lower extremity and the development of lower extremity injuries in basketball, soccer and track and field athletes. In addition, Schinkel-Ivy et al (2012) found that the peak shock (measured as acceleration) at the tibial tuberosity was significantly affected by the mass of the tissues located in the distal lower extremity. Pain and Challis (2002) suggested that ignoring the role of soft tissue motion may limit our understanding of injury prevention strategies.…”

“…The movement of soft tissue masses (fat, muscle, skin) with respect to the underlying bone in the lower extremities is thought to serve a protective role during drop landings (Pain & Challis, 2006;Schinkel-Ivy, Burkhart, & Andrews, 2012), walking (Zelik & Kuo, 2010) and running (Cole, Nigg, Van Den Bogert, & Gerritsen, 1996) by attenuating potentially injurious impact forces. In many biomechanical analyses of such events, soft tissue movement relative to bone has been viewed as error (or soft tissue/motion artefact) and researchers typically quantify its magnitude and remove it from their data rather than studying its importance (Peters, Galna, Sangeux, Morris, & Baker, 2010).…”

Validation of a full body finite element model (THUMS) for running-type impacts to the lower extremity

“…For example, in comparison with rigid body models (representing bone) and wobbling mass models (representing rigid and soft tissues), the latter substantially reduced both external and internal loading (Gruber et al 1998;Liu and Nigg 2000;Pain and Challis 2001Gittoes et al 2006). Furthermore, Schinkel-Ivy et al (2012) found that greater shank tissue masses, specifically lean mass and bone mineral content, contributed to decreased acceleration responses measured at the proximal tibia following impact.…”

“…A human pendulum (, 13 kg; Flynn et al 2004;Holmes and Andrews 2006;Andrews 2010a, 2010b;Schinkel-Ivy et al 2012) was used to swing the participant towards a rigid impact apparatus. The participant was positioned supine on the pendulum with the left leg in full extension (knee joint line situated at the leading edge of the pendulum).…”