Hamstring Strain Injury in Athletes PDF

Hamstring Strain Injury in Athletes DPT 414 1446 Dr. Samiah Alqabbani Injury Mechanics and Prevalence Hamstring strains occur when there is a sudden, forceful contraction or an intense stretch of the hamstring muscles, leading to high mechanical str...

Hamstring Strain Injury in Athletes DPT 414 1446 Dr. Samiah Alqabbani Injury Mechanics and Prevalence Hamstring strains occur when there is a sudden, forceful contraction or an intense stretch of the hamstring muscles, leading to high mechanical stress. Characterized by a sudden pain in the back of the thigh, resulting from the disruption of hamstring muscle fibers, without any direct external impact to the area. Hamstring strain injuries are common in activities that involve high- speed running, jumping, kicking, and/or explosive lower extremity movements with rapid changes in direction, including lifting objects from the ground. A professional soccer team of 25 players can expect about 7 HSIs per season. Hamstring strain injuries frequently cause a significant loss of time from competition, generally ranging from 3 to 28 days or more, depending on injury severity we on Relevant anatomy and Biomechanics Except for the biceps femoris short head, the complex is biarticular, crossing both hip and knee joints. A concentric contraction of the complex produces hip extension and knee flexion, whereas an eccentric contraction controls hip flexion and knee extension. During many sport activities, the hamstring produce high levels of force eccentrically for proper stabilization across the hip and knee joints. duringQuadConcentric The inability to produce sufficient force in a lengthening position increases the muscle's susceptibility to injury. Following a hamstring injury, there is a shift in peak knee flexion torque development to a shorter musculotendon length (greater knee flexion angle). Injury recurrence has been linked to this shift in the torque-angle relationship, because force development in elongated position is compromised. eccentric  at imperot Relevant anatomy and Biomechanics Even High-speed running is the most common cause of hamstring strain injuries , followed by movements that involve significant force and hamstring lengthening, such as kicking. Why High-speed running? engobility The terminal swing phase during high-speed running is eccentrics prone to injury. The hamstrings are highly active, rapidly lengthening, and absorbing energy to slow down the limb before foot contact. As running speed increases from 80% to 100% of maximum, hamstring muscle force rises by about 1.3 times, with the greatest stretch occurring in the long head of the biceps femoris. Recovery from High-speed vs. Kicking The precise anatomic location of injury within the hamstring muscle complex varies between injuries resulting from high-speed running and those resulting from slow excessive stretching. During high-speed running, most often involving the intramuscular tendon of the biceps femoris long head. As the limb enters the terminal swing phase, the hamstrings are actively lengthening to decelerate the limb for initial contact with the ground. The biceps femoris long head undergoes the greatest amount of musculotendon stretch and load, which explain its high incidence of injury during these movements compared to the semitendinosus and semimembranosus. In contrast, hamstring injuries during activities such kicking occur within the proximal tendon of the semimembranosus because of excessive musculotendon stretch. The location of a hamstring injury affects recovery time. Injuries to the intramuscular tendon of the biceps femoris long head, often caused by high-speed running, tend to heal faster than injuries to the proximal free tendon of the semimembranosus.  Risk Factors Nonmodifiable Previous Hamstring strain: the greatest single risk factors for developing recurrent hamstring strain. ( 2- to 6-times higher rate of recurrence following a previous HSI). Age: (athletes older than 23 years of age were at greater risk than those 23 years of age or younger (RR = 1.34). Additionally, in Australian rules football athletes older ok than 25 years of age were at greater risk than those 25 years of age or younger (RR = 4.43) Modifiable Hamstring weakness in eccentric contraction Lumbopelvic weakness (attachment of hamstring to the pelvis) Hamstring to quadriceps strength imbalance (Isokinetic measurements) Examination Form Sudden onset of posterior thigh pain. c not Other symptoms may include an audible pop, antalgic gait with shortened stride length. Ecchymosis, posterior thigh swelling, and pain with sitting or direct pressure. Physical examination include pain and weakness with resisted knee flexion and hip extension, pain with passive hip flexion and knee extension, pain with palpation. recovery Mechanism of injury, involved structures, location of tenderness, and time to return to pain-free walking are prognostic factors for injury recovery and should be determined during the examination. Muscle Strength Measurements Hamstring strength testing should be conducted in the prone position, with the hip stabilized at 0° extension. Medial and lateral hamstring muscles can be targeted using internal and external tibial rotation at 90° and 15° of knee flexion, respectively. Hip extension strength should be evaluated with the knee at 90° and 0°, applying manual resistance to the distal posterior thigh and heel. ROM Measurements submit Range of motion is measured with the passive straight leg SF raise test and the active knee extension test. Hamstring tightness is present if the hip joint angle is less than 80° during the passive straight leg raise and if the knee flexion angle is greater than 20° during the active knee extension test. The active knee extension test is a reliable measure of hamstring flexibility in patients with acute hamstring injury (1 day to walk pain-free walk without following injury are more likely to require >3 pain weeks of rehabilitation prior to 100% return to sport. Active knee extension This test is not associated with the time needed test to return to sport or risk of hamstring re-injury. Intervention  In the early rehabilitation phase, goals should focus on normalizing gait, managing pain and swelling, and initiating pain-free submaximal hamstring strengthening in a mid-length position. Early hip and knee ROM contribute to less disorganized scar formation and a lower Rehabilitation reinjury rate. Progressive agility and trunk stabilization Goals and exercises (PATS) are introduced to enhance lumbopelvic control, potentially lowering re- Intervention FEW injury risk by enabling the hamstring to operate at a safe length during dynamic movements. The benefits of PATS include promoting full eccentric controlled early loading through frontal-plane movements while avoiding end-range hamstring lengthening.  Following an acute hamstring injury, the optimal length for active tension shortens due to neuromuscular changes or scar tissue formation, which can begin as early as 7-days post-injury. Therefore, Eccentric strengthening is beneficial in shifting peak force development to longer musculotendon lengths. By allowing the muscle to generate more force at smaller knee flexion angles, this approach may reduce injury Rehabilitation risk during high-speed running when eccentric loads peak near terminal extension. Goals and Eccentric strengthening should commence when patients can perform a pain-free, submaximal isometric hamstring Intervention contraction, initially targeting submaximal contractions in the mid-range of motion. Once the athlete achieves 5/5 strength at 90° knee flexion, they can advance to end-range strengthening with increased loads. The final rehabilitation phase includes sport-specific drills and return-to-sport testing. Due to the high re-injury risk, athletes must meet all specified criteria before returning to full participation Progressive Agility and Trunk Stabilization (PATS) Program Progressive agility and trunk stabilization (PATS) program initiated within the first week following acute hamstring strains significantly decreased injury recurrence during the first 2 weeks and 1 year following return to sport compared to a program consisting of traditional hamstring stretching and strengthening. Examples of exercises in the PATS program include sidestepping (3 sets of 1 minute), cariocas (3 sets of 1 minute), boxer shuffle (3 sets of 1 minute), and rotating side planks 3 sets of 20 repetitions).  Progressive Running A progressive return to high-speed running and sprinting is a key component of rehabilitation, as these activities are crucial for performance in many sports and are common causes of HSI. A 3-stage running protocol is used in rehabilitation. Stage 1 begins once the athlete can walk with minimal pain, starting with slow jogging (about 25% of maximum speed) and progressing to moderate- speed running (around 50% of maximum speed). Stage 2 is introduced once moderate-speed running is pain-free, while Stage 3 involves gradual progression toward sprinting (up to 100% of maximum speed), with increments of about 5% to reduce the risk of re-injury, especially as the hamstring faces greater eccentric loads at speeds over 80% of maximum. Eccentric ms of rehab Exercise Eccentric hamstring exercises are a common imputt HSI rehabilitation intervention to prepare athletes for the demands of high-speed running and address deficits in strength and muscle structure. Research supports the use of eccentric strengthening in effective hamstring injury prevention programs over concentric training. End range Eccentric Strengthening Examples Single-limb windmill Single-limb chair- bridge Single-leg deadlift Supine bent knee walk out.  Clinical Practice Guidelines "Hamstring Strain Injury in Athletes" Martin, R. R. L., Cibulka, M. T., Bolgla, L. A., Koc, T. A., Loudon, J. K., Manske, R. C., … Heiderscheit, B. C. (2022, March 1). Hamstring Strain Injury in Athletes. Journal of Orthopaedic and Sports Physical Therapy. Movement Science Media. https://doi.org/10.2519/jospt.2022.0301  Interventions Intervention After Injury The systematic review by de Visser et al. noted a lower risk of hamstring strain reinjury when individuals performed agility and stabilization exercises after injury, compared to only stretching and strengthening exercises (7.7% versus 70%, respectively).  Injury Prevention Prevention of First-Time Injury Return to Sport A systematic review by Hickey et al. recommended a combination of clinical assessment (manual muscle testing, ROM, palpation), performance (sprinting, agility, hopping, sport-specific movements), and isokinetic dynamometry tests to inform RTP decision making. Return to sport Criteria 1. Maximal isometric strength of at least 4 repetions at various degrees of knee flexion (e.g., 90° and 15°) with medial and lateral tibial rotation bias 2. Full, pain-free hip and knee ROM 3. Isokinetic testing demonstrating less than 5% deficit of eccentric hamstring to concentric quadriceps ratio 4. No palpable tenderness along the posterior thigh 5. Functional and sport-specific tasks without pain or apprehension 6. No pain or apprehension with active hamstring test. The active hamstring test, a ballistic flexibility test requiring a rapid straight leg raise, helps identify athletes' discomfort with near-end-range hamstring movements. Among those who passed passive flexibility and standard exams post-injury, 95% still felt insecure with this test. Repeated testing every two weeks showed that athletes who no longer felt insecure remained injury-free four weeks post-return. Standard hops (height, distance, crossover) are not effective return-to-sport criteria for hamstring injuries. Return to sport Implication The significance of return-to-sport criteria is underscored by findings from various imaging studies. Silder et al. reported that MRI scans showed evidence of ongoing muscle injury in 26% of the hamstring muscle complex's cross-sectional area at the time athletes returned to sport, even when they had met standard return-to- sport criteria. Similarly, Sanfilippo et al. found persistent edema on MRI in athletes returning to sport after a hamstring strain, along with a reduction in isokinetic knee flexor torque, both of which only resolved six months post-injury. These findings highlight the importance for physical therapists to recognize that morphologic and strength deficits in the hamstring muscle may persist, despite athletes meeting return-to-sport standards. Implementing an ongoing progressive eccentric and lumbopelvic strengthening program post- return can help athletes reach previous performance levels while reducing re- injury risk. Summary Early rehab focuses on pain control, gait normalization, and gentle strengthening. PATS exercises, eccentric training enhance stability and reduce re-injury risk. Athletes must meet criteria like full range of motion and passing strength tests. Continued eccentric and core strengthening helps prevent re-injury.  so is References 55 2 5 Heiderscheit, Bryan C., et al. "Hamstring strain injuries: recommendations for diagnosis, rehabilitation, and injury prevention." journal of orthopaedic & sports physical therapy 40.2 (2010): 67-81. Hickey, Jack T., et al. "Hamstring strain injury rehabilitation." Journal of athletic training 57.2 (2022): 125-135. Huygaerts S, Cos F, Cohen DD, Calleja-González J, Guitart M, Blazevich AJ, et al. Mechanisms of hamstring strain injury: Interactions between fatigue, muscle activation and function. Sports. 2020;8(5):1–15. Martin, R. R. L., Cibulka, M. T., Bolgla, L. A., Koc, T. A., Loudon, J. K., Manske, R. C., … Heiderscheit, B. C. (2022, March 1). Hamstring Strain Injury in Athletes. Journal of Orthopaedic and Sports Physical Therapy. Movement Science Media. https://doi.org/10.2519/jospt.2022.0301