Influence of acute endurance activity on leg neuromuscular and musculoskeletal performance

Abstract

Even though strength performance near to full knee extension was preserved following acute endurance activities, the risk of ligamentous injury may be increased by concomitant impairment to EMD and anterior TFD.

Effects of acute fatigue on the volitional and magnetically-evoked electromechanical delay of the knee flexors in males and females

“…The magnitude of PF V performance decrement observed in the current study (15% for males and 10% for females) is congruent with the extent of performance loss associated with match play in team games such as soccer (Gleeson et al 1998b). These findings, together with corroborating findings from other studies (e.g.…”

“…This warm-up was equivalent to that used in other recent studies within this laboratory examining the effects of various interventions on indices of volitional neuromuscular performance (Gleeson 2001;Gleeson et al 2000;Gleeson et al 1998a;Gleeson et al 1998b;Mercer et al 1998). …”

“…Gleeson et al 2000;Gleeson et al 1998b;Zhou et al 1996) may suggest a reduced capability of the dynamic stabilisers to provide forceful corrective responses to mechanical loading of the knee. Such fatigue-related changes in neuromuscular performance may be interpreted to represent an increased risk of injury (Chan et al 2001;Gleeson et al 1998b;Mercer et al 1998), which may be amplified particularly at knee angles where key ligamentous structures are already under greatest mechanical strain (Beynnon and Johnson 1996).…”

“…While the decrements to PF V capabilities of males exceeded that experienced by females (PF V : 15% vs. 10%, respectively), a group mean increase in EMD V latencies from pre-to post-fatigue levels (19.3%) was observed exclusively in females. Recent research that has indicated that the reaction time of the neuromuscular system to imposed dynamic forces may be fundamental to the protection of the joint system (Gleeson et al 2000;Gleeson et al 1998a;Gleeson et al 1998b;Huston and Wojtys 1996;Mercer et al 1998;Shultz et al 2001) may suggest such concomitant increases in EMD V may affect the timely correction of joint forces and be associated with exacerbation of injury risk. Indeed, the current results may provide a new insight into the complex phenomenon that describes a five-to seven-fold increase risk of ACL injury in the female athlete compared to male counterparts (Gray et al 1985;Ireland et al 1997).…”

Repeated exercise stress impairs volitional but not magnetically evoked electromechanical delay of the knee flexors

“…Furthermore, there is limited information in the literature on the recovery process of EMD after a fatiguing exercise. In situations where where is a limited time frame for the most rapid and protective responses of the neuromuscular system to counteract potentially harmful dynamic joint forces, sub-optimal performance may present additional injury risk (Shultz et al, 2001;Mercer, Gleeson, Claridge, Clement, 1998;Gleeson, Reilly, Mercer, Morris, Rees, 1998;Huston & Wojtys, 1996). Spontaneous or reflexive responses to emergency scenarios including 'fight or flight' responses would be expected to reflect an individual's true maximal performance capability.…”