Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production (original) (raw)
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Frontiers in Physiology, 2018
Aim: Hamstring muscle injury is the main injury related to sports requiring sprint acceleration. In addition, hamstring muscles have been reported to play a role in horizontal force production during sprint acceleration performance. The aim of the present study was to analyze (i) the determinants of horizontal force production and (ii) the role of hip extensors, and hamstring muscles in particular, for horizontal force production during repeated sprint-induced fatigue conditions. Method: In this experimental laboratory setting study including 14 sprint-trained male athletes, we analyzed (i) the changes in sprint mechanics, peak torque of the knee and hip extensors and flexors, muscle activity of the vastus lateralis, rectus femoris, biceps femoris, and gluteus, and sagittal plane lower limb motion, before and after twelve 6s sprints separated by 44 s rest on an instrumented motorized treadmill, and (ii) the determinants of horizontal force production (F H) during the sprint acceleration in a fatigue state (after 12 sprints). Results: The repeated-sprint protocol induced a decrease in maximal power output (Pmax) [−17.5 ± 8.9%; effect size (ES): 1.57, large] and in the contact-averaged horizontal force component (F H) (−8.6 ± 8.4%; ES: 0.86, moderate) but not meaningful changes in the contact-averaged resultant (total) force (F Tot) (−3.4 ± 2.9%; ES: 0.55, small) and vertical force component (F V) (−3.1 ± 3.2%; ES: 0.49, small). A decrease was found in concentric peak torque of the knee flexors and extensors and in gluteus and
Hamstring muscle kinematics and activation during overground sprinting
Journal of Biomechanics, 2008
Hamstring muscle strain injury is one of the most commonly seen injuries in sports such as track and field, soccer, football, and rugby. The purpose of this study was to advance our understanding of the mechanisms of hamstring muscle strain injuries during over ground sprinting by investigating hamstring muscle-tendon kinematics and muscle activation. Three-dimensional videographic and electromyographic (EMG) data were collected for 20 male runners, soccer or lacrosse players performing overground sprinting at their maximum effort. Hamstring muscle-tendon lengths, elongation velocities, and linear envelop EMG data were analyzed for a running gait cycle of the dominant leg. Hamstring muscles exhibited eccentric contractions during the late stance phase as well as during the late swing phase of overground sprinting. The peak eccentric contraction speeds of the hamstring muscles were significantly greater during the late swing phase than during the late stance phase (p ¼ 0.001) while the hamstring muscle-tendon lengths at the peak eccentric contraction speeds were significantly greater during the late stance phase than during the late swing phase (p ¼ 0.001). No significant differences existed in the maximum hamstring muscle-tendon lengths between the two eccentric contractions. The potential for hamstring muscle strain injury exists during the late stance phase as well as during the late swing phases of overground sprinting.
Frontiers in Sports and Active Living, 2021
To train hamstring muscle specifically to sprint, strengthening programs should target exercises associated with horizontal force production and high levels of hamstring activity. Therefore, the objectives of this study were to analyze the correlation between force production capacities during sprinting and hamstring strengthening exercises, and to compare hamstring muscle activity during sprinting and these exercises. Fourteen track and field regional level athletes performed two maximal 50-m sprints and six strengthening exercises: Nordic hamstring exercises without and with hip flexion, Upright-hip-extension in isometric and concentric modalities, Standing kick, and Slide-leg-bridge. The sprinting horizontal force production capacity at low (F0) and high (V0) speeds was computed from running velocity data. Hamstring muscle performances were assessed directly or indirectly during isolated exercises. Hamstring muscle electromyographic activity was recorded during all tasks. Our res...
European Journal of Applied Physiology, 2020
Purpose We determined whether running mechanics and leg muscle activity patterns for pre-activation (50 ms prior to foot contact) and loading (first half, second half and entire stance) phases vary between early, late and entire acceleration phases during repeated treadmill sprints. Methods Ten male athletes performed three sets of five 5-s sprint accelerations (25-s and 3-min recovery between sprints and sets, respectively) on an instrumented treadmill. Ground reaction forces and surface EMG data (root mean square values of vastus lateralis, rectus femoris, biceps femoris, gastrocnemius medialis, gastrocnemius lateralis and tibialis anterior muscles of the right leg) corresponding to early, late and entire acceleration (steps 2, 4 and 6; steps 8, 10 and 12; and all steps, respectively) have been compared. Results Independently of fatigue, vertical and horizontal forces, contact time, step length, and step frequency differed as running velocity increased over different sprint acceleration sections (all P < 0.05). For pre-activation, first half, second half and entire stance phases taken separately, each of the six studied muscles displayed specific main sprint number and analysis section effects (all P < 0.05). However, there was in general no significant interaction between sprint number and analysis section (all P > 0.27). Conclusion During repeated treadmill sprints, ground reaction force variables and leg muscle activity patterns can vary between early, late and entire acceleration phases. Identification of neuro-mechanical adjustments across the gait cycle with fatigue, however, did not differ when considering all steps or only a few steps during the early or late acceleration phases.
Amplitude and timing of electromyographic activity during sprinting
Scandinavian Journal of Medicine & Science in Sports, 2007
Amplitude and timing of electromyographic activity during sprinting. Scand J Med Sci Sports 1996: 6: 15-21. 0 Munksgaard, 1996 The aim of this study was to make descriptive analyses of the muscle activities in the lower extremity during maximal sprinting. Nine healthy sprinters were examined during maximal sprinting using telemetric electromyography (EMG). Seven muscles of the lower extremities were investigated: biceps femoris, medial hamstrings (semimembranosus and semitendinosus), rectus femoris, gluteus maximus, tibialis anterior, lateral gastrocnemius and medial gastrocnemius. The recorded EMG levels during running were expressed as percentage of maximum voluntary isometric contractions ('%omax EMG). For each muscle, the normalized EMG was plotted during the whole running stride cycle and is presented for each muscle. The reason for using this method is to show that it is possible to compare different muscle activities in a runner as well as to make comparisons between runners. Lateral and medial hamstrings and gluteus maximus showed similar activities with peak levels of EMG during footstrike. Rectus femoris had a two-peak activity, with one peak at the middle of the stance phase and the other during the swing phase. The tibialis anterior also showed a two-peak activity, but with the peaks at the beginning of the swing phase and just before foot-strike. The highest activities of the medial and lateral gastrocnemius occurred just before toe-off.
Journal of Sports Sciences, 2021
This study determined the effects of two wearable resistance (WR) placements (i.e. thigh and shank) on horizontal force-velocity and impulse measures during sprint running acceleration. Eleven male athletes performed 50 m sprints either unloaded or with WR of 2% body mass attached to the thigh or shank. Inground force platforms were used to measure ground reaction forces and determine dependent variables of interest. The main findings were: 1) increases in sprint times and reductions in maximum velocity were trivial to small when using thigh WR (0.00−1.93%) and small to moderate with shank WR (1.56−3.33%); 2) athletes maintained or significantly increased horizontal force-velocity mechanical variables with WR (effect size = 0.32−1.23), except for theoretical maximal velocity with thigh WR, and peak power, theoretical maximal velocity and maximal ratio of force with shank WR; 3) greater increases to braking and vertical impulses were observed with shank WR (2.72−26.3% compared to unloaded) than with thigh WR (2.17−12.1% compared to unloaded) when considering the entire acceleration phase; and, 4) no clear trends were observed in many of the individual responses. These findings highlight the velocity-specific nature of this resistance training method and provide insight into what mechanical components are overloaded by lower-limb WR.
Orthopaedic Journal of Sports Medicine, 2020
Background: Although running can provide health benefits, knee joint injuries are frequently reported by recreational runners. To date, the precise mechanism responsible for anterior knee pain remains elusive, and the source of symptoms is debated. Inconsistencies are found in the literature pertaining to the relationship between hip mechanics and activity in the quadriceps and gluteus maximus (GMax) during the running gait. Purpose/Hypothesis: To investigate the correlations between hip rotation and the activity in the quadriceps and GMax during running. We hypothesized that increased hip rotation is correlated with decreased activity in these muscles. Study Design: Descriptive laboratory study. Methods: A cohort of 30 healthy recreational runners volunteered to participate in the study (mean ± SD age, 28.8 ± 5.66 years; height, 1.73 ± 0.05 m; mass, 69 ± 6.3 kg; body mass index, 23.02 ± 1.42 kg/m2). Surface electromyography (EMG) data were obtained from the GMax, vastus medialis ob...
ISBS - Conference Proceedings Archive, 2016
The purpose of this study was to identify which lower limb joint moments of force and lower limb muscles had the highest contribution to the forward and upward acceleration of the Body Centre of Gravity (BCG) in an elite sprinter during the first step after starting from blocks in 100 meters dash. An induced acceleration analysis approach was used to mechanically ascertain this contribution. Two models were used, one based in a simple multilink rigid body's model and a second using a musculoskeletal model developed using Opensim. Our results showed a possible synergist action between hip and ankle extensors that allow an optimal combination that resulted in a forward propulsion of the BCG, this results seem to be corroborated using an Opensim musculoskeletal model.
International Journal of Environmental Research and Public Health, 2021
Clear decreases in horizontal force production capacity during sprint acceleration have been reported after hamstring injuries (HI) in football players. We hypothesized that lower FH0 is associated with a higher HI occurrence in football players. We aimed to analyze the association between sprint running horizontal force production capacities at low (FH0) and high (V0) velocities, and HI occurrence in football. This prospective cohort study included 284 football players over one season. All players performed 30 m field sprints at the beginning and different times during the season. Sprint velocity data were used to compute sprint mechanical properties. Players’ injury data were prospectively collected during the entire season. Cox regression analyses were performed using new HI as the outcome, and horizontal force production capacity (FH0 and V0) was used at the start of the season (model 1) and at each measurement time point within the season (model 2) as explanatory variables, adj...