Hamstring Injury

 

Prevalence varies by sport ranging from 8 to 25 percent with a high recurrence rate frequently during the ensuing sport season, usually in next 2 months but may extend up to one year!

 

Highest in sports that involve rapid acceleration and deceleration

            3 highest risk sports - football and men’s and women’s soccer

Average time lost 17-21 days

Injury much less common in younger athletes

 

The hamstring is composed of three muscles: the biceps femoris, semitendinosus, and semimembranosus.

Primarily involved in knee flexion and hip extension

 

Biceps femoris is most commonly injured

https://www.ncbi.nlm.nih.gov/books/NBK539862/figure/article-28873.image.f1

 

Simple grading system using 3 grades

Grade 1 – mild strain

Grade 2 – Partial tear

Grade 3 – Complete tear

Proximal injuries are more common than distal injuries, occurring at the musculotendinous junction

Avulsion fractures of the ischium occur rarely occur in adults but may occur in skeletally immature athletes

https://radiopaedia.org/cases/ischial-tuberosity-avulsion

When watching a sporting event you will see the athlete grab the buttock or upper thigh. They usually cannot return to play. Most grade 2 or 3 injuries will require crutches. If seeing them the following day significant bruising may be seen.

Numerous modifiable and non-modifiable risk factors have been identified including:

*Weakness of ipsilateral quadriceps or contralateral hamstring, hamstring, hip & quadriceps tightness/poor flexibility, poor warm-up, sudden increased training volume and muscle fatigue.

*Older age (risk increase may begin as early as age 23)

Prior hamstring injury (up to 6x increased risk)

            **Premature return to sport increases the risk of reinjury

Differential Diagnosis:  Lumbar radiculopathy, sciatic nerve irritation or compression, stress fracture of femur.

 

Refer to sports medicine/orthopedics for avulsion injuries, complete proximal complete tears and partial or complete distal tears