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In vivo biomechanical study for injury prevention
Published in Youlian Hong, Roger Bartlett, Routledge Handbook of Biomechanics and Human Movement Science, 2008
Mario Lamontagne, D. L. Benoit, D. K. Ramsey, A. Caraffa, G. Cerulli
During the stopping movement task, the average peak strain of the ACL was 5.47 ± 0.28%. It is noted that the strain in the ACL rises during the flight phase prior to impact. Peak strain occurs at the point of impact of the left foot (instrumented leg) and the strain in the ACL was maintained relatively high for the duration of the hop cycle. The ACL strain at the impact with ground after the flight phase was more than 2.75 times higher than the instrumented Lachman test. Qualitative video analysis of the movement trials indicated that the knee never reached full extension during the stopping tasks. It was further observed that the leg was most extended at the time of impact during the landing phase. During the flight phase, there is an extension of the knee joint and muscle activation of the quadriceps, hamstring and gastrocnemius muscles in preparation for landing. Although there is a continuous increase in ACL strain until reaching maximum strain at the impact, immediately prior to impact, ACL strain is already at 5%. Consequently, the bone geometry and muscle contraction induce important ACL strain.
Spinal Cord and Reflexes
Published in Nassir H. Sabah, Neuromuscular Fundamentals, 2020
The largest and longest peripheral nerve, that is, a nerve outside the central nervous system, is the sciatic nerve. In humans, it is a flat thick band, about 2 cm wide, formed by the grouping of spinal nerves L4 to S3. It originates in the lower back, runs through the buttock and thigh, and divides, usually at the back of the knee joint, into the tibial nerve and the common fibular (or peroneal) nerve. The sciatic nerve directly controls the muscles of the posterior thigh and the hamstring portion of the adductor magnus muscle. Its branches control the muscles of the leg and foot. These branches also convey signals from the skin of the lateral leg and the foot.
The Mechanics of Gait
Published in Verna Wright, Eric L. Radin, Mechanics of Human Joints, 2020
Knee flexion is provided by four groups of muscles (Fig. 7). All but two of these cross another joint and thus have an additional function. The popliteus and biceps femoris short head (BFSH) are the two purely knee flexors. Normal phasing of the BFSH is in initial swing. There is no clear phasic pattern for the popliteus. It appears to respond to a hyperextension thrust and also to intiate knee flexion at times. Both vary considerably among individuals. Hamstring knee flexor action is dominated by hip extensor roles in terminal swing and loading response. The gastrocnemius is also capable of flexing the knee, but its primary role is as an ankle plantar flexor during stance.
Assessment of muscle volume using magnetic resonance imaging (MRI) in football players after hamstring injuries
Published in European Journal of Sport Science, 2022
Nils Mühlenfeld, Ida Bo Steendahl, Daniel P. Berthold, Tim Meyer, Thomas Hauser, Nils Wagner, Anna-Lena Sander, Ingo Marzi, Benjamin Kaltenbach, Ibrahim Yel, Thomas Vogl, Katrin Eichler
Approval from the institutional review board of the medical faculty and local ethics committee (41/18) was obtained prior to performing this study. Informed consent was obtained from all individual participants included in the study. Recreational football players sustaining hamstring muscle injuries between 01/2018 and 03/2019 were prospectively enrolled. Subjects eligible for study inclusion had to be 18 years or older with a hamstring injury sustained during a football-match or practice. The injury was confirmed as a fresh injury in the hamstring muscle group by magnetic resonance imaging (MRI) by a specialised radiologist within 3 days of injury and classified according to the Munich classification (Mueller-Wohlfahrt et al., 2013). Participants had to be available for a radiographic follow-up 3 and 6 weeks after the initial trauma. Football players with multiple injuries in muscles other than the hamstring muscle group, complete proximal or distal hamstring (avulsion) injuries, previous hamstring injuries within the last 12 months, as well as any other concomitant injuries to the lower extremity were excluded from this study. Only male patients were included to achieve a homogenous data set.
Exercise interventions to prevent hamstring injuries in athletes: A systematic review and meta-analysis
Published in European Journal of Sport Science, 2020
Rok Vatovec, Žiga Kozinc, Nejc Šarabon
The aim of this paper was to systematically review and meta-analytically assess the effects of exercise interventions on the incidence of hamstring injuries in sport. Our results confirmed the findings from previous reviews, which showed that interventions are successful in reducing hamstring injury risk. Furthermore, this meta-analysis showed that weekly frequency and load progression are not among the most important variables in these interventions. All eccentric exercise, balance training and muscle stretching are effective strategies to reduce hamstring injury rates. Additionally, a specific warm-up routine (FIFA 11+), which includes a combination of resistance and balance exercises, was found to be a good example of time-efficient and effective comprehensive intervention in this respect.
Hamstring muscles’ function deficit during overground sprinting in track and field athletes with a history of strain injury
Published in Journal of Sports Sciences, 2019
Ayako Higashihara, Takashi Ono, Gaku Tokutake, Rieko Kuramochi, Yasuhiro Kunita, Yasuharu Nagano, Norikazu Hirose
Known risk factors for hamstring strain injury include age (Gabbe, Bennell, Finch, Wajswelner, & Orchard, 2006), strength deficits (Opar et al., 2015a; Sugiura, Saito, Sakuraba, Sakuma, & Suzuki, 2008), flexibility (Arnason, Andersen, Holme, Engebretsen, & Bahr, 2008; Henderson, Barnes, & Portas, 2010), and fatigue (Ekstrand, Hagglund, & Walden, 2010). Additionally, a history of hamstring injury is a strong predictor of future injury (Arnason et al., 2004; Gabbe et al., 2006; Hagglund, Walden, & Ekstrand, 2006). Previous studies have suggested that neuromuscular inhibition of voluntary hamstring activation occurs following hamstring strain injury (Bourne, Opar, Williams, Al Najjar, & Shield, 2016; Opar, Williams, Timmins, Dear, & Shield, 2013). This inhibition detrimentally affects hamstring recovery by limiting hamstring exposure to eccentric stimuli at long muscle lengths during rehabilitative exercises (Fyfe, Opar, Williams, & Shield, 2013). Daly et al. found that athletes with a history of hamstring strain injury have significantly reduced BFlh muscle activation ratios with respect to the ipsilateral Gmax muscle in the late swing phase of treadmill running (Daly, Persson, Twycross-Lewis, Woledge, & Morrissey, 2016). They speculated that the decrease in BFlh muscle activity may have contributed to the increased anterior pelvic tilt and hip flexion, resulting in increased hamstring length. However, other previous studies did not find significant intra-limb differences in the activation pattern and musculotendon length of BFlh muscle during treadmill sprinting (Silder, Thelen, & Heiderscheit, 2010) or any inter-limb differences in the kinematics of running between previously injured and uninjured limbs during overground running (Lee, Reid, Elliott, & Lloyd, 2009; Schuermans et al., 2017). This discrepancy may be explained by the possible differences in the methodology (e.g. treadmill vs. overground running) of data collection. Furthermore, the sprinting speed should be considered during such investigations because hamstring strain injuries often occur during high-speed running. Further investigations with overground running and approximately maximum speed are required to elucidate the effects of previous injury on the hamstring function.