S56.01 - Strain of flexor muscle, fascia and tendon of thumb at forearm level S56.0 - Injury of flexor muscle, fascia and tendon of thumb at forearm level S56.01 - Strain of flexor muscle, fascia and tendon of thumb at forearm level S56.011 - Strain of flexor muscle, fascia and tendon of right thumb at forearm level S56.012 - Strain of flexor muscle, fascia and tendon of left thumb at forearm level S56.019 - Strain of flexor muscle, fascia and tendon of unspecified thumb at forearm level