In the general population, one-third of incidences during step negotiation occur during the transition to level walking. Furthermore, falls during curb negotiation are a common cause of injury in older adults. Distal foot kinematics may be an important factor in determining injury risk associated with transition step negotiation. The purpose of this study was to identify foot and ankle kinematics of uninjured individuals during descent from varying step heights. A 7-segment foot model was used to quantify kinematics as participants walked on a level walkway, stepped down a single step (heights: 5 cm, 15 cm, 25 cm), and continued walking. As step height increased, landing strategy transitioned from the rearfoot to the forefoot, and the rearfoot, lateral and medial midfoot, and medial forefoot became more plantar flexed. During weight acceptance, sagittal plane range of motion of the rearfoot, lateral midfoot, and medial and lateral forefoot increased as step height increased. The changes in landing strategy and distal foot function suggest a less stable ankle position at initial contact and increased demand on the distal foot at initial contact and through the weight acceptance phase of transition step negotiation as step height increases.
Emily E. Gerstle, Kristian O’Connor, Kevin G. Keenan and Stephen C. Cobb
Gina L. Trakman, Adrienne Forsyth, Kane Middleton, Russell Hoye, Sarah Jenner, Stephen Keenan and Regina Belski
Sports nutrition is an evolving field, but there is a lack of data on Australian athletes’ knowledge of current sports nutrition guidelines. Additionally, several tools used to assess nutrition knowledge (NK) have not undergone adequate validation. The purpose of this study was to assess and compare the sports NK of elite and nonelite Australian football (AF) athletes using a newly validated questionnaire—The Nutrition for Sport Knowledge Questionnaire. Elite AF players (n = 46) were recruited directly from their club dietitian and nonelite AF players (n = 53) were invited to participate via e-mail from their club president or secretary. The mean NK score of elite and nonelite AF players was 46 ± 16% and 51 ± 11%, respectively (p = .041). In both groups, knowledge of macronutrients, weight management, and alcohol was better than knowledge of supplements, micronutrients, and sports nutrition. Nonelite athletes achieved statistically significantly higher scores on the questionnaire subsections testing weight management (elite: 48 ± 18; nonelite: 57 ± 19, p = .019), micronutrients (elite: 39 ± 19; nonelite: 50 ± 16, p = .004), and alcohol (elite: 52 ± 13; nonelite: 71 ± 17, p = .002). While overall NK of Australian athletes was poor, scores varied greatly among individuals (range: 10–70%) and across the six subsections (topics) being assessed. Professionals working with athletes should undertake an assessment of the athletes’ NK so that they can provide targeted education programs.
Lauren C. Benson, Stephen C. Cobb, Allison S. Hyngstrom, Kevin G. Keenan, Jake Luo and Kristian M. O’Connor
Low foot clearance and high variability may be related to falls risk. Foot clearance is often defined as the local minimum in toe height during swing; however, not all strides have this local minimum. The primary purpose of this study was to identify a nondiscrete measure of foot clearance during all strides, and compare discrete and nondiscrete measures in ability to rank individuals on foot clearance and variability. Thirty-five participants (young adults [n = 10], older fallers [n = 10], older nonfallers [n = 10], and stroke survivors [n = 5]) walked overground while lower extremity 3D kinematics were recorded. Principal components analysis (PCA) of the toe height waveform yielded representation of toe height when it was closest to the ground. Spearman’s rank order correlation assessed the association of foot clearance and variability between PCA and discrete variables, including the local minimum. PCA had significant (P < .05) moderate or strong associations with discrete measures of foot clearance and variability. An approximation of the discrete local minimum had a weak association with PCA and other discrete measures of foot clearance. A PCA approach to quantifying foot clearance can be used to identify the behavioral components of toe height when it is closest to the ground, even for strides without a local minimum.