PURPOSE: The purpose of this study was to describe the muscle activation patterns of the vastus lateralis (VL), medial hamstrings (MH) and lateral hamstrings (LH) associated with subjects that were anterior cruciate ligament (ACL) deficient and controls. METHODS: A total of 54 subjects participated in this study including 25 ACL deficient subjects subdivided into copers (n=9) and non-copers (n=16) using clinical criteria. Muscle activation patterns were recorded at 1000 Hz during an unanticipated side step cut task. The root mean square processed data (time constant 11 ms) were ensemble averaged from 20% of stance before heel strike to toe off. Using the first five harmonics of the Fourier Coefficients as features, muscle activation patterns were divided using a cluster analysis algorithm. RESULTS: A majority (76-93%) of control subjects used three muscle activation patterns for each muscle. The coper group preferentially used a particular VL and MH activation pattern >2 times more frequently than controls. The non-coper group also preferentially used a MH activation pattern >2 times more frequently than controls and utilized a unique MH and LH activation pattern, distinct from the copers and controls. CONCLUSIONS: Specific muscle activation patterns distinguish subsets of subjects that are healthy and injured, suggesting possible patterns of muscle activation that contribute to coping status.
PURPOSE: The purpose of this study was to describe the muscle activation patterns of the vastus lateralis (VL), medial hamstrings (MH) and lateral hamstrings (LH) associated with subjects that were anterior cruciate ligament (ACL) deficient and controls. METHODS: A total of 54 subjects participated in this study including 25 ACL deficient subjects subdivided into copers (n=9) and non-copers (n=16) using clinical criteria. Muscle activation patterns were recorded at 1000 Hz during an unanticipated side step cut task. The root mean square processed data (time constant 11 ms) were ensemble averaged from 20% of stance before heel strike to toe off. Using the first five harmonics of the Fourier Coefficients as features, muscle activation patterns were divided using a cluster analysis algorithm. RESULTS: A majority (76-93%) of control subjects used three muscle activation patterns for each muscle. The coper group preferentially used a particular VL and MH activation pattern >2 times more frequently than controls. The non-coper group also preferentially used a MH activation pattern >2 times more frequently than controls and utilized a unique MH and LH activation pattern, distinct from the copers and controls. CONCLUSIONS: Specific muscle activation patterns distinguish subsets of subjects that are healthy and injured, suggesting possible patterns of muscle activation that contribute to coping status.
Authors: Pedro Alvarez-Diaz; Eduard Alentorn-Geli; Silvia Ramon; Miguel Marin; Gilbert Steinbacher; Juan José Boffa; Xavier Cuscó; Oscar Ares; Jordi Ballester; Ramon Cugat Journal: Knee Surg Sports Traumatol Arthrosc Date: 2014-09-25 Impact factor: 4.342
Authors: Louise M Thoma; Hege Grindem; David Logerstedt; Michael Axe; Lars Engebretsen; May Arna Risberg; Lynn Snyder-Mackler Journal: Am J Sports Med Date: 2019-02-21 Impact factor: 6.202