An ACL injury is the tearing of the anterior cruciate ligament — one of the major ligaments in your knee. ACL injuries most commonly occur during sports that involve sudden stops, jumping or changes in direction — such as basketball, soccer, football, tennis, downhill skiing, volleyball and gymnastics.
Many people hear or feel a “pop” in the knee when an ACL injury occurs. Your knee may swell, feel unstable and become too painful to bear weight.
Depending on the severity of your ACL injury, treatment may include rest and rehabilitation exercises to help you regain strength and stability or surgery to replace the torn ligament followed by rehabilitation. A proper training program may help reduce the risk of an ACL injury.
Signs and symptoms of an ACL injury usually include:
- A loud “pop” or a “popping” sensation in the knee
- Severe pain and inability to continue activity
- Swelling that begins within a few hours
- Loss of range of motion
- A feeling of instability or “giving way” with weight bearing
Ligaments are strong bands of tissue that connect one bone to another. The ACL, one of two ligaments that cross in the middle of the knee, connects your thighbone (femur) to your shinbone (tibia) and helps stabilize your knee joint.
Most ACL injuries happen during sports and fitness activities that can put stress on the knee:
- Suddenly slowing down and changing direction (cutting)
- Pivoting with your foot firmly planted
- Landing from a jump incorrectly
- Stopping suddenly
- Receiving a direct blow to the knee or collision, such as a football tackle
When the ligament is damaged, there is usually a partial or complete tear across the tissue. A mild injury may overextend the ligament but leave it intact.
How Physical Therapy helps with ACL Tears
Treatment Without Surgery
Current research has identified a specific group of patients (called “copers”) who have the potential for healing without surgery following an ACL tear. These patients have injured only the ACL, and have experienced no episodes of the knee “giving out” following the initial injury. If you fall into this category, based on the specific tests your physical therapist will conduct, your therapist will design an individualized physical therapy treatment program for you. It may include treatments such as gentle electrical stimulation applied to the quadriceps muscle, muscle strengthening, and balance training.
Treatment Before Surgery
If your orthopedic surgeon determines that surgery is necessary, your physical therapist can work with you before and after your surgery. Some surgeons refer their patients to a physical therapist for a short course of rehabilitation before surgery. Your physical therapist will help you decrease your swelling, increase the range of movement of your knee, and strengthen your thigh muscles (quadriceps).
Treatment After Surgery
Your orthopedic surgeon will provide post-surgery instructions to your physical therapist, who will design an individualized treatment program based on your specific needs and goals. Your treatment program may include:
Bearing weight. Following surgery, you will use crutches to walk. The amount of weight you are allowed to put on your leg and how long you use the crutches will depend on the type of reconstructive surgery you have received. Your physical therapist will design a treatment program to meet your needs and gently guide you toward full weight bearing.
Icing and compression. Immediately following surgery, your physical therapist will control your swelling with a cold application, such as an ice sleeve, that fits around your knee and compresses it.
Bracing. Some surgeons will give you a brace to limit your knee movement (range of motion) following surgery. Your physical therapist will fit you with the brace and teach you how to use it safely. Some athletes will be fitted for braces as they recover and begin to return to their sports activities.
Movement exercises. During your first week following surgery, your physical therapist will help you begin to regain motion in the knee area, and teach you gentle exercises you can do at home. The focus will be on regaining full movement of your knee. The early exercises help with increasing blood flow, which also helps reduce swelling.
Electrical stimulation. Your physical therapist may use electrical stimulation to help restore your thigh muscle strength, and help you achieve those last few degrees of knee motion.
Strengthening exercises. In the first 4 weeks after surgery, your physical therapist will help you increase your ability to put weight on your knee, using a combination of weight-bearing and non-weight-bearing exercises. The exercises will focus on your thigh muscles (quadriceps and hamstrings) and might be limited to a specific range of motion to protect the new ACL. During subsequent weeks, your physical therapist may increase the intensity of your exercises and add balance exercises to your program.
Balance exercises. Your physical therapist will guide you through exercises on varied surfaces to help restore your balance. Initially, the exercises will help you gently shift your weight on to the surgery leg. These activities will progress to standing on the surgery leg, while on firm and unsteady surfaces to challenge your balance.
Return to sport or activities. As athletes regain strength and balance, they may begin running, jumping, hopping, and other exercises specific to their individual sport. This phase varies greatly from person-to-person. Physical therapists design return-to-sport treatment programs to fit individual needs and goals.