ICD-10-CM > S00-T88 > S80-S89 > S86 > S86.2 > S86.21 S86.21 Strain of muscle(s) and tendon(s) of anterior muscle group at lower leg level Non-Billable/Non-Specific Codes S86.211Strain of muscle(s) and tendon(s) of anterior muscle group at lower leg level, right legS86.211A..., initial encounterS86.211D..., subsequent encounterS86.211S..., sequelaS86.212Strain of muscle(s) and tendon(s) of anterior muscle group at lower leg level, left legS86.212A..., initial encounterS86.212D..., subsequent encounterS86.212S..., sequelaS86.219Strain of muscle(s) and tendon(s) of anterior muscle group at lower leg level, unspecified legS86.219A..., initial encounterS86.219D..., subsequent encounterS86.219S..., sequela