The effect of anterior cruciate ligament rupture on the timing and amplitude of gastrocnemius muscle activation: A study of alterations in EMG measures and their relationship to knee joint stability

Altered knee joint neuromuscular control during landing from a jump in 10–15year old children with Generalised Joint Hypermobility. A substudy of the CHAMPS-study Denmark

“…Landing with more extended knees could cause higher quadriceps activity for the GJH group, but this was not found in the current study. Also, the higher level of activity in the GM for the GJH group rejects this hypothesis, as GM is both a knee flexor and a knee joint stabiliser (Klyne et al, 2012). It is well known, that activation of the knee flexors may counteract the anteriorly directed shear force (Aagaard et al, 2000;Hewett et al, 2005), providing stability to the knee joint.…”

Lower extremity muscle activation onset times during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects

“…The majority of previous studies assessing muscle activation patterns after ACL injury mainly focused on muscles surrounding the injured knee joint (Aalbersberg et al, 2009;Beard et al, 1993;Boerboom et al, 2001;Branch et al, 1989;Bryant et al, 2009;Ciccotti et al, 1994;Gauffin & Tropp, 1992;Houck et al, 2007;Kalund et al, 1990;Klyne et al, 2012;Lindstrom et al, 2009;Sinkjaer & Arendt-Nielsen, 1991;Swanik et al, 1999Swanik et al, , 2004Wojtys & Huston, 1994). The current study is the first to evaluate muscle activation onset times of the knee, hip and ankle after ACL injury during a standardized functional task, the transition from DLS to SLS.…”

The reliability of determining the onset of medial gastrocnemius muscle activity during a stretch-shorten-cycle action

“…Detecting the onset of muscle activity from surface electromyography (sEMG) recordings has been performed using a number of methods including visual onset detection (Allison, 2003;Klyne et al, 2012) and computer based methods (Hodges and Bui, 1996;Kuriki et al, 2011). Determination of muscle onset visually requires the investigator to inspect the processed sEMG signal graphically and identify the point at which there is an increase in muscle activity beyond baseline (Hodges and Bui, 1996;Kuriki et al, 2011).…”

“…Determination of muscle onset visually requires the investigator to inspect the processed sEMG signal graphically and identify the point at which there is an increase in muscle activity beyond baseline (Hodges and Bui, 1996;Kuriki et al, 2011). Identifying muscle onset then allows determination of temporal and amplitude characteristics of the sEMG signal including: duration of muscle contraction (Klyne et al, 2012), the rate of change of the signal (Santello, 2005) and the duration and amplitude of the sEMG signal relative to events such as initial ground contact (IC) during a gait cycle (Hobara et al, 2010).…”