De Vos et al identified risk factors associated with re-injury of a hamstring. These can help to identify a patient who may benefit from more aggressive management. The authors are from Aspetar Orthopaedic and Sports Medicine Hospital (Doha, Qatar) and multiple universities in The Netherlands.


Patient selection: athlete just after return to play following hamstring injury


Risk factors associated with re-injury of the hamstring:

(1) number of previous injuries to that hamstring

(2) deficit in active knee extension

(3) deficit in isometric knee flexion force with knee at 15 degrees flexion

(4) localized discomfort on palpation of the hamstring



• The isomeric knee flexion force is performed with the knee flexed to 15 degrees. A dynamometer measures the force exerted by the the athlete as the athlete resists the force made by the examiner. The reading in the injured leg is compared to the reading from the uninjured leg.


number of risk factors =

= (number of risk factors present)



• minimum number of risk factors: 0

• maximum number of risk factors: 4

• The risk increases with the number of risk factors and their severity.


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