ACL Tear

August 13th, 2022

Anterior Cruciate Ligament (ACL)

  • ACL and PCL (posterior cruciate ligament) act together as major (most importantly, rotational) stabilizers of knee joint
  • ACL prevents hyperextension and shearing of knee joint and controls rotational movements of tibia (shin bone) on femur (thigh bone), or vice versa, during pivoting or side-stepping movements; PCL prevents femur from sliding forward on tibia (or tibia from sliding backwards on femur)
  • Cruciate ligaments provide proprioceptive feedback (perception of movement and spatial orientation) from knee to central nervous system

ACL Tear

  • common mechanisms of injury are hyperextension of leg and/or sudden rotational force with foot planted
  • severe compromise of ligament causes knee to buckle and give way

Physical Therapy Treatment

  • as per post-surgical treatment (as indicated; see below), though shorter timeline
  • possible bracing of knee (cast for fitting as swelling abates) for use during high-intensity activity to compensate for lack of ligament and stabilize knee

Physical Therapy Treatment


  • initially, pain and swelling addressed using RICE approach (rest, ice, compression, elevation) and electrotherapeutic modalities (e.g., IFC, ultrasound, cryotherapy)
  • early joint mobilization, soft tissue stretching, and controlled loading stimulate healing of articular cartilage and bone and transformation of graft to become more ligamentous
  • range of motion and strength increased gradually



  • gradual return to desired activity to avoid stretching repaired tissue beyond optimal tension: dynamic function increased with partial to full weight bearing activity; progressed to include conditioning, global limb strength, agility, functional re-training activities
  • return to full sports participation may take between 4 months to a year
  • recovery time frames vary somewhat according to type of graft used and other individual differences
  • graft repair tissue at its weakest between 6 to 12 weeks post-surgery


  • gradual return to normal function can begin when brace (if prescribed) provided and/or strength returned
  • non-rotational sports or activities such as walking, hiking, running, cycling, and swimming begin first; more rotational sports such as tennis, skiing or soccer resumed when no swelling and no pain felt after running or hiking

Physio Note: Activity Precaution

Avoid resisted leg extension exercise which exerts shear forces on joint that may cause tearing of compromised ligament (non-surgical patient) or vulnerable repair graft (post-surgically)

Your physical therapist will utilize modalities to reduce inflammation, facilitate resolution of swelling, and speed healing and can help you set up a safe and effective exercise routine to meet your evolving needs