Hamstring injury patterns in professional male football (soccer): a systematic video analysis of 52 cas

2021 ◽  
pp. bjsports-2021-104769
Author(s):  
Thomas Gronwald ◽  
Christian Klein ◽  
Tim Hoenig ◽  
Micha Pietzonka ◽  
Hendrik Bloch ◽  
...  
Keyword(s):  
Video Analysis ◽  
High Speed ◽  
Pattern Analysis ◽  
Specific Pattern ◽  
Hamstring Injury ◽  
Injury Patterns ◽  
Open Chain ◽  
Indirect Contact ◽  
Hamstring Injuries ◽  
Closed Chain

ObjectiveTo closely describe the injury inciting events of acute hamstring injuries in professional male football (soccer) using systematic video analysis.MethodsVideo footage from four seasons (2014–2019) of the two highest divisions in German male football was searched for moderate and severe (ie, time loss of >7 days) acute non-contact and indirect contact match hamstring injuries. Two raters independently categorised inciting events using a standardised procedure to determine specific injury patterns and kinematics.Results52 cases of hamstring injuries were included for specific pattern analysis. The pattern analysis revealed 25 sprint-related (48%) and 27 stretch-related hamstring injuries (52%). All sprint-related hamstring injuries occured during linear acceleration or high-speed running. Stretch-related hamstring injuries were connected with closed chain movements like braking or stopping with a lunging or landing action and open chain movements like kicking. The kinematic analysis of stretch-related injuries revealed a change of movement involving knee flexion to knee extension and a knee angle of <45° at the assumed injury frame in all open and closed chain movements. Biceps femoris was the most affected muscle (79%) of all included cases.ConclusionDespite the variety of inciting events, rapid movements with high eccentric demands of the posterior thigh are likely the main hamstring injury mechanism. This study provides important data about how hamstring injuries occur in professional male football and supports the need for demand-specific multicomponent risk reduction programmes.

scholarly journals Evaluation of Ankle Mobility Loss in Patients Undergoing Subtalar Arthrodesis

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0011
Author(s):  
Tiago S. Baumfeld ◽  
Roberto Zambelli de A. Pinto ◽  
Fernando Araujo S. Lopes ◽  
Daniel Baumfeld ◽  
Camilo Tavares
Keyword(s):  
Range Of Motion ◽  
Plantar Flexion ◽  
Contralateral Side ◽  
Foot And Ankle ◽  
Lower Range ◽  
Open Chain ◽  
Subtalar Arthrodesis ◽  
Closed Chain ◽  
Ankle Mobility ◽  
Dorsal Flexion

Category: Hindfoot Introduction/Purpose: Objective: To evaluate and quantify the loss of ankle mobility in patients undergoing subtalar arthrodesis compared to the contralateral side, through physical examination. Methods: A total of 12 patients who had only the subtalar arthrodesis procedure from various causes in one foot were selected. The same foot and ankle surgeon performed all measurements of bilateral tibiotarsal range of motion, with loaded closed-chain and unloaded open-chain tests. Then, to assess whether there was a difference between the operated and the non-operated side, statistical analysis was performed with the Mann-Whitney test (Hollander and Wolfe 1999). Results: On the loaded closed-chain test, the operated side had a significantly lower range of motion than the contralateral side, with a mean difference of 5.4 degrees for dorsal flexion and 7.6 degrees for plantar flexion. The open-chain tests showed non- significant differences of 3 degrees for dorsal flexion and 5.3 degrees for plantar flexion. Conclusion: Subtalar joint arthrodesis was shown to cause a loss of mobility in the ipsilateral ankle, which is greater in plantar flexion movement.

Hamstring rehabilitation in elite track and field athletes: applying the British Athletics Muscle Injury Classification in clinical practice

2019 ◽  
Vol 53 (23) ◽  
pp. 1464-1473 ◽  
Author(s):  
Ben Macdonald ◽  
Stephen McAleer ◽  
Shane Kelly ◽  
Robin Chakraverty ◽  
Michael Johnston ◽  
...  
Keyword(s):  
Muscle Injury ◽  
Clinical Presentation ◽  
Classification Systems ◽  
Track And Field ◽  
Hamstring Injury ◽  
Shared Decision ◽  
Injury Rehabilitation ◽  
Hamstring Injuries ◽  
Elite Sports ◽  
Injury Classification

RationaleHamstring injuries are common in elite sports. Muscle injury classification systems aim to provide a framework for diagnosis. The British Athletics Muscle Injury Classification (BAMIC) describes an MRI classification system with clearly defined, anatomically focused classes based on the site of injury: (a) myofascial, (b) muscle–tendon junction or (c) intratendinous; and the extent of the injury, graded from 0 to 4. However, there are no clinical guidelines that link the specific diagnosis (as above) with a focused rehabilitation plan.ObjectiveWe present an overview of the general principles of, and rationale for, exercise-based hamstring injury rehabilitation in British Athletics. We describe how British Athletics clinicians use the BAMIC to help manage elite track and field athletes with hamstring injury. Within each class of injury, we discuss four topics: clinical presentation, healing physiology, how we prescribe and progress rehabilitation and how we make the shared decision to return to full training. We recommend a structured and targeted diagnostic and rehabilitation approach to improve outcomes after hamstring injury.

scholarly journals Spectra of Local Cluster Flows on Open Chain of Contours

2018 ◽  
Vol 11 (3) ◽  
pp. 628-644 ◽  
Author(s):  
Alexander Pavlovich Buslaev ◽  
Alexander G Tatashev
Keyword(s):  
Dynamical System ◽  
Unit Length ◽  
Self Organization ◽  
Similar System ◽  
Open Chain ◽  
Local Cluster ◽  
Closed Chain

A dynamical system is considered. This dynamical system is a flow of clusters with the same length $l$ on contours of unit length connected into open chain. A similar system such that contours of this system are connected into closed chain was considered earlier. It has been found that, in the case of closed chain of contours, the dynamical system has a spectrum of velocity and mode periodicity consisted of more than one component. In this paper, it has been shown that, in the case of open chain, the spectrum of cluster velocity and mode periodicity contains only one component.The conditions of self-organization and the dependence of cluster velocity on load $l$ is developed.

Difference of Hamstring Activity Between Bilateral and Unilateral Nordic Hamstring Exercises With a Sloped Platform

2021 ◽  
pp. 1-6
Author(s):  
Toshiaki Soga ◽  
Taspol Keerasomboon ◽  
Kei Akiyama ◽  
Norikazu Hirose
Keyword(s):  
High Speed ◽  
Biceps Femoris ◽  
Break Point ◽  
Hamstring Injury ◽  
Emg Activity ◽  
Maximum Voluntary Isometric Contraction ◽  
Mean Values ◽  
Significant Difference ◽  
Long Head ◽  
Control Study

Context: This study aimed to examine the differences in electromyographic (EMG) activity of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles, break-point angle (BPA), and the angle at peak BFlh EMG activity between bilateral and unilateral Nordic hamstring exercise (NHE) on a sloped platform. Design: This study was designed as a case-control study. Methods: Fourteen men participated in the study. The participants initially performed maximum voluntary isometric contraction (MVIC) on the prone leg curl to normalize the peak hamstring EMG amplitude as the %MVIC. Then, participants were randomized to perform the following 3 variations of NHE: bilateral (N40) or unilateral (N40U) NHE with a platform angle of 40°, and unilateral NHE with a platform angle of 50° (N50U). The EMG activities of the BFlh and ST and the knee flexion angle during the NHE variations were recorded to calculate the EMG activity of the BFlh and ST in terms of the %MVIC, the angle at peak BFlh EMG, and BPA. Results: The BFlh %MVIC was significantly higher in N40U (P < .05) and N50U (P < .05) than in N40. A significant difference in BFlh %MVIC and ST %MVIC was observed between N40U (P < .05) and N50U (P < .05). The mean values of BPA and the angle at peak BFlh EMG were <30° for all NHE variations. Conclusions: In the late swing phase of high-speed running, BFlh showed higher EMG activity; thus, unilateral NHE may be a specific hamstring exercise for hamstring injury prevention.

Injury patterns of mass casualty incidents involving high-speed passenger ferries presenting to accident and emergency departments in Hong Kong: a retrospective review

Injury ◽  
2020 ◽  
Vol 51 (2) ◽  
pp. 252-259 ◽  
Author(s):  
Rex Pui Kin Lam ◽  
Ronald Tat Ming Wong ◽  
Eric Ho Yin Lau ◽  
Kin Wa Wong ◽  
Arthur Chi Kin Cheung ◽  
...  
Keyword(s):  
Hong Kong ◽  
Retrospective Review ◽  
Emergency Departments ◽  
High Speed ◽  
Mass Casualty ◽  
Mass Casualty Incidents ◽  
Injury Patterns ◽  
Accident And Emergency

Mechanisms of acute ankle syndesmosis ligament injuries in professional male rugby union players: a systematic visual video analysis

2020 ◽  
pp. bjsports-2020-102281
Author(s):  
Eamonn Delahunt ◽  
Garreth Farrell ◽  
Andrew Boylan ◽  
Fearghal Kerin ◽  
Peter Tierney ◽  
...  
Keyword(s):  
Video Analysis ◽  
Direct Contact ◽  
External Rotation ◽  
Rugby Union ◽  
Qualitative Description ◽  
Ligament Injuries ◽  
Injured Limb ◽  
Indirect Contact ◽  
Injury Mechanisms ◽  
Hip Flexion

BackgroundThe mechanisms of acute ankle syndesmosis ligament injuries in professional rugby union are not well understood.AimTo describe the mechanisms of acute ankle syndesmosis ligament injuries in male professional rugby union players using systematic visual video analysis.MethodsAll time-loss acute ankle syndesmosis ligament injuries identified via retrospective analysis of the Leinster Rugby injury surveillance database across the 2013/2014 to 2017/2018 seasons were considered as potentially eligible for inclusion. Three Chartered Physiotherapists (analysts) independently assessed all videos with a final consensus meeting convened to describe the injury mechanisms. One of the analysts developed a qualitative description of each injury mechanism.ResultsThirteen acute ankle syndesmosis injuries were included in this study. The most common biomechanical presentation of the injured limb was characterised by hip flexion, knee flexion, knee valgus, ankle dorsiflexion, pronation and external rotation of the foot. Six of the included injuries (46%) were the result of an external load application to the injured limb (ie, direct contact injuries). In the other seven instances (54%), the injury was the result of a collapse of the injured player’s body mass over the injured ankle joint, while tackling or being tackled, without direct contact to the injured limb (ie, indirect contact injuries).ConclusionInjuries incurred while tackling were exclusively the result of suboptimal tackle mechanics. A majority of injuries incurred while being tackled involved a posterior tackle, which often resulted in a posterior collapse of the injured player’s centre of mass over a fixed externally rotated foot.

scholarly journals Systematic video analysis of ACL injuries in professional male football (soccer): injury mechanisms, situational patterns and biomechanics study on 134 consecutive cases

2020 ◽  
Vol 54 (23) ◽  
pp. 1423-1432 ◽  
Author(s):  
Francesco Della Villa ◽  
Matthew Buckthorpe ◽  
Alberto Grassi ◽  
Alberto Nabiuzzi ◽  
Filippo Tosarelli ◽  
...  
Keyword(s):  
Video Analysis ◽  
Direct Contact ◽  
Acl Injury ◽  
Injury Pattern ◽  
Biomechanical Analysis ◽  
Knee Valgus ◽  
Mechanical Perturbation ◽  
Indirect Contact ◽  
Acl Injuries ◽  
Injury Mechanisms

BackgroundA few small studies have reported on the mechanisms of ACL injury in professional male football.AimTo describe the mechanisms, situational patterns and biomechanics (kinematics) of ACL injuries in professional male football matches.MethodsWe identified 148 consecutive ACL injuries across 10 seasons of professional Italian football. 134 (90%) injury videos were analysed for mechanism and situational pattern, while biomechanical analysis was possible in 107 cases. Three independent reviewers evaluated each video. ACL injury epidemiology (month), timing within the match and pitch location at the time of injury were also reported.Results59 (44%) injuries were non-contact, 59 (44%) were indirect contact and 16 (12%) were direct contact. Players were frequently perturbed immediately prior to injury. We identified four main situational patterns for players who suffered a non-contact or an indirect contact injury: (1) pressing and tackling (n=55); (2) tackled (n=24); (3) regaining balance after kicking (n=19); and (4) landing from a jump (n=8). Knee valgus loading (n=83, 81%) was the dominant injury pattern across all four of these situational patterns (86%, 86%, 67% and 50%, respectively). 62% of the injuries occurred in the first half of the matches (p<0.01). Injuries peaked at the beginning of the season (September–October) and were also higher at the end of the season (March–May).Conclusions88% of ACL injuries occurred without direct knee contact, but indirect contact injuries were as frequent as non-contact injuries, underlying the importance of mechanical perturbation. The most common situational patterns were pressing, being tackled and kicking.

EXACT GROUND STATES OF ONE-DIMENSIONAL VALENCE-BOND-SOLID HAMILTONIANS

1987 ◽  
Vol 01 (05n06) ◽  
pp. 231-237 ◽  
Author(s):  
P.L. Iske ◽  
W.J. Caspers
Keyword(s):  
Ground State ◽  
Valence Bond ◽  
Ground States ◽  
Open Chain ◽  
State Correlation ◽  
One Dimensional ◽  
Degenerate Ground State ◽  
Closed Chain ◽  
Ground State Correlation ◽  
Valence Bond Solid

The ground state(s) of a Hamiltonian, introduced by Affleck, Kennedy, Lieb and Tasaki, in connection with the Valence-Bond-Solid (VBS) states, are explicitly given for the spin-1 chains. The structure of these ground states is a rather simple one. For a closed chain we find a unique ground state; for the open chain we find a fourfold-degenerate ground state. The ground state correlation function for the ring is calculated.

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