Quadriceps and hamstrings muscle control in athletic males and females

Abstract

The aim of this study was to investigate whether athletic males and females have differences in their quadriceps and hamstrings muscle control strategies. Twenty-four people (12 males, 12 females) active in level I activities volunteered to participate. The subjects' muscle control strategies were studied using electromyography and a target matching protocol that assesses one's ability to produce force with control. The degree of control exhibited in the subjects' quadriceps and hamstrings muscle activation strategies was evaluated by calculating specificity indices for each muscle using circular statistics. Females displayed significantly lower specificity than males in their vastus medialis (p < 0.001), rectus femoris (p ¼ 0.044), and lateral hamstrings (p ¼ 0.001) muscle activity patterns, but similar specificity in their vastus lateralis and medial hamstrings activity patterns. Females also used a significantly higher magnitude of vastus lateralis (p < 0.001) and vastus medialis (p < 0.001) muscle activity than males to achieve the same relative force level. These findings indicate athletic males and females have differences in their knee muscle control strategies. ß

Joint stabilisers or moment actuators: The role of knee joint muscles while weight-bearing

“…Non-weight-bearing isometric force matching studies indicate that muscle activation is directly related to its moment arm orientation, leading to asymmetrical activation patterns and high muscle specificities (Buchanan and Lloyd, 1997;Krishnan et al, 2008;Lloyd and Buchanan, 2001;Williams et al, 2003). However, we found low measures of specificity in all muscles (Fig.…”

“…The ST was also deemed a moment actuator because its relatively specific activation pattern occurred about its reported moment arm orientation MAO (Buchanan and Lloyd, 1997), similar to previous studies which investigated the movement facilitation capabilities of knee muscles (Buchanan and Lloyd, 1997;Krishnan et al, 2008;Lloyd and Buchanan, 2001;Williams et al, 2003).…”

“…To achieve this, isometric knee exercises have been used, however, evaluations usually focused on flexion and extension (Hortobagyi et al, 2004;Rainoldi et al, 2001) even though functional activities do not limit loads to these directions. Appreciating this, Buchanan and Lloyd (1997), and many studies since (Benoit et al, 2006;Krishnan et al, 2008;Buchanan, 1996, 2001;Williams et al, 2003) implemented an isometric force matching protocol to evaluate neuromuscular strategies used to support various combinations of flexion-extensionvarus-valgus loads at the knee. Subsequently, electromyographic (EMG) data were plotted in polar coordinates (Dewald et al, 1995) so muscle activation patterns could be quantified, described, and compared across test populations.…”

Tibial acceleration profiles during the menstrual cycle in female athletes

“…Gender differences in the tibial acceleration profiles could reflect differences in pre-activation of antagonist muscles, resulting in earlier eccentric contraction in the male athlete; several prior studies are consistent with this suggestion [11,14,26,45]. Gehring et al assessed two-legged landings and noticed a significant delay (P = 0.05) in hamstring and quadriceps activation in females [14].…”

“…Furthermore, Ebben et al investigated hamstring and quadriceps activation patterns using EMG and observed earlier activation of both muscle groups in males [11]. Finally, Krishnan et al observed different between gender activation patterns for hamstring and quadriceps muscles; females displayed significantly lower (P \ 0.001) muscle activity patterns, and also displayed a significantly higher magnitude of quadriceps (P \ 0.001) muscle activity than males to achieve the same relative force [26].…”