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Full-Text Articles in Rehabilitation and Therapy
Muscle-Specific Contributions To Lower Extremity Net Joint Moments While Squatting With Different External Loads, Kristof Kipp, Hoon Kim, William I. Wolf
Muscle-Specific Contributions To Lower Extremity Net Joint Moments While Squatting With Different External Loads, Kristof Kipp, Hoon Kim, William I. Wolf
Exercise Science Faculty Research and Publications
The purpose of this study was to determine muscle-specific contributions to lower extremity net joint moments (NJMs) during squats with different external loads. Nine healthy subjects performed sets of the back squat exercise with 0, 25, 50, and 75% of body mass as an added external load. Motion capture and force plate data were used to calculate NJMs and to estimate individual muscle forces via static optimization. Individual muscle forces were multiplied by their respective moment arms to calculate the resulting muscle-specific joint moment. Statistical parametric mapping (α = 0.05) was used to determine load-dependent changes in the time series …
Maximal Strength In Relation To Force And Velocity Patterns During Countermovement Jumps, Michael H. Haischer, John Krzyszkowski, Stuart Roche, Kristof Kipp
Maximal Strength In Relation To Force And Velocity Patterns During Countermovement Jumps, Michael H. Haischer, John Krzyszkowski, Stuart Roche, Kristof Kipp
Exercise Science Faculty Research and Publications
Maximal strength is important for the performance of dynamic athletic activities, such as countermovement jumps (CMJ). Although measures of maximal strength appear related to discrete CMJ variables, such as peak ground reaction forces (GRF) and center-of-mass (COM) velocity, knowledge about the association between strength and the time series patterns during CMJ will help characterize changes that can be expected in dynamic movement with changes in maximal strength. Purpose: To investigate the associations between maximal strength and GRF and COM velocity patterns during CMJ. Methods: Nineteen female college lacrosse players performed 3 maximal-effort CMJs and isometric midthigh pull. GRF …
Hip And Knee Joint Angle Patterns And Kicking Velocity In Female And Male Professional Soccer Players: A Principal Component Analysis Of Waveforms Approach, Archit Navandar, Kristof Kipp, Enrique Navarro
Hip And Knee Joint Angle Patterns And Kicking Velocity In Female And Male Professional Soccer Players: A Principal Component Analysis Of Waveforms Approach, Archit Navandar, Kristof Kipp, Enrique Navarro
Exercise Science Faculty Research and Publications
This study used principal component analysis (PCA) of waveforms to extract movement patterns from hip and knee angle time-series data; and determined if the extracted movement patterns were predictors of ball velocity during a soccer kick. Twenty-three female and nineteen male professional soccer players performed maximal effort instep kicks while motion capture and post-impact ball velocities data were recorded. Three-dimensional hip and knee joint angle time-series data were calculated from the beginning of the kicking leg’s backswing phase until the end of the follow-through phase and entered into separate PCAs for females and males. Three principal components (PC) (i.e., movement …
Head Impact Exposure In Youth And Collegiate American Football, Grace B. Choi, Eric P. Smith, Stefan M. Duma, Steven Rowson, Eamon Campolettano, Mireille E. Kelley, Derek A. Jones, Joel D. Stitzel, Jillian E. Urban, Amaris Genemaras, Jonathan G. Beckwith, Richard M. Greenwald, Arthur C. Maerlender, Joseph J. Crisco
Head Impact Exposure In Youth And Collegiate American Football, Grace B. Choi, Eric P. Smith, Stefan M. Duma, Steven Rowson, Eamon Campolettano, Mireille E. Kelley, Derek A. Jones, Joel D. Stitzel, Jillian E. Urban, Amaris Genemaras, Jonathan G. Beckwith, Richard M. Greenwald, Arthur C. Maerlender, Joseph J. Crisco
Center for Brain, Biology, and Behavior: Faculty and Staff Publications
The relationship between head impact and subsequent brain injury for American football players is not well defined, especially for youth. The objective of this study is to quantify and assess Head Impact Exposure (HIE) metrics among youth and collegiate football players. This multiseason study enrolled 639 unique athletes (354 collegiate; 285 youth, ages 9–14), recording 476,209 head impacts (367,337 collegiate; 108,872 youth) over 971 sessions (480 collegiate; 491 youth). Youth players experienced 43 and 65% fewer impacts per competition and practice, respectively, and lower impact magnitudes compared to collegiate players (95th percentile peak linear acceleration (PLA, g) competition: 45.6 vs …