An ankle sprain is an injury to the tough bands of tissues or ligaments that surround and connect the bones of the leg to the foot. The injury occurs due to twisting or turning the ankle accidentally in an awkward way, as this can stretch or tear the ligaments that hold the ankle bones and joints together.
All ligaments have a specific range of motion and limitations that allow them to keep the joints stabilized. When ligaments surrounding the ankle are overstretched making them cross their boundaries, it causes a sprain that commonly involves injuries to the ligaments on the outside of the ankle.
Depending on the severity, ligament injury can be classified into:

• Grade I: is an injury without stretching the ligament.
• Grade II: is an injury in which the ligament remains intact or with a more severe sprain, it can be partially torn.
• Grade III: is an injury in which there is a complete rupture of the ligament.

Grade I: is characterized by the patient's inability to run and jump, difficulty in stair climbing, and the patient feels discomfort, but the ligaments are intact.
Grade II: requires support to walk, the patient feels significant pain, swelling, and bruising.
Grade III: in which weight-bearing is impossible, pain is high, immobilization is usually required and surgery is often required.

The inflammation associated with sprained ankle can cause symptoms such as:

• Pain in the ankle
• Swelling and bruising around the ankle
• Pain aggravates when pressed or when the foot is moved in certain ways while walking, or standing
• Redness and warmth around the ankle
• Instability due to weakness, when the ligament is torn
• Difficulty in walking

Pathology: Ankle sprain causes stretching or tearing of one or more ligaments, the tough fibrous bands that hold the ankle bones in place. Sprains can be caused by accident, sports injury, or stepping on an uneven surface. Symptoms may include pain, inflammation, stiffness, and bruising. It also causes mechanical instability due to specific insufficiencies such as pathologic laxity, arthrokinematic changes, synovial irritation, or degenerative changes.

An ankle sprain occurs when the ankle is forced to move out of its normal position, which causes one or more of the ankle's ligaments to stretch, partially tear or tear completely. Causes of an ankle sprain may include:

• Fall that can cause the ankle to twist
• Awkwardly landing on the foot after jumping or pivoting
• Exercising or walking on an uneven surface
• Another person stepping or landing on the foot during a sports activity

Physical Examination: The examiner examines the ankle, foot, and lower leg. He/she touches the skin around the injury to check for tenderness and swelling, and the range of motion is checked to understand the extent of discomfort or pain.
CT scan: CT scans take X-rays from different angles and combine them to make cross-sectional or 3-D images. CT scans are done to reveal more detail about the bones of the joint.
MRI: Magnetic resonance imaging uses radio waves and a strong magnetic field to produce 3-D images of soft internal structures and a detailed cross-sectional image of the ankle, including ligaments.
X-ray: X-ray is done in which a small amount of radiation passes through the body to produce images of the bones of the ankle. This test is done to rule out bone fractures.

Medications: Anti-inflammatory pain medications etc.
Note: Medication should not be taken without the doctor’s prescription.
Surgery: Surgery for sprained ankles is rarely done. It may be done when the damage to the ligament is severe and instability is severe, or when the injury doesn't improve with conventional treatment. Surgical options include:

• Arthroscopy: In arthroscopy, the surgeon looks inside the joint to see if there are any loose fragments of bone or cartilage.
• Reconstruction: In reconstruction surgery, the surgeon repairs the torn ligament with stitches, or other ligaments or tendons around the foot can be used to repair the damaged ligaments.

Rest: Rest is recommended to prevent loading on the affected joint.
Cryotherapy: Ice therapy should be done for 3-7 days after an injury for pain and swelling reduction.
Range of motion exercises: Simple range of motion exercises can be done to improve joint mobility. Even passive range of motion for dorsiflexion can be performed in both positions of weight-bearing or non-weight-bearing.
Compression: Compression bandaging like elastic bandaging is applied to reduce swelling and improve healing.
Elevation: The affected limb is elevated up to 15-25 cm above the level of the heart to assist with lymphatic drainage.
Ankle support: An ankle brace should be used for a minimum of 6 months to protect the damaged tissues. A semi-rigid brace or lace-up brace is recommended for individuals with a prior history of ankle sprains.
Kinesio Taping: Kinesio taping helps to provide sufficient mechanical support for an unstable joint.
Transcutaneous Electrical stimulation: Transcutaneous Electrical stimulation is found to be effective to decrease swelling and pain.
Laser Therapy: Laser therapy is also used to reduce pain and swelling.
Therapeutic Ultrasound: Therapeutic ultrasound decreases pain, and edema improves function and helps the patient to return to daily activities.
Manual Therapy: Manual therapy includes soft tissue massage, lymphatic drainage, anterior to posterior talocrural glides, and talocrural distraction in the neutral position. Manual therapy helps in pain reduction, reduces stiffness, and causes functional recovery.
Stretching Exercises: Stretching exercises can be started with an open-chain exercise in all planes, dorsiflexion stretch with upper extremity assistance, and further progress to closed chain exercises. Heel cord stretching should be initiated as soon as possible.
Strengthening Exercises: Strengthening exercises are started immediately for grade I and II sprains, whereas for grade III sprain is postponed, inversion and eversion of the ankle should be minimized. The exercises are started with isometrics in frontal and sagittal planes, progress to isotonic resistive exercises with weights, elastic bands, or manual resistance, add movement in all planes, slow movements performed within pain limits, and high repetitions e.g 23 sets with 10 repetitions.
Proprioceptive Neuromuscular Facilitation: Proprioceptive neuromuscular facilitation (PNF) exercises cause a significant improvement in ankle function and pain-free higher activity levels.
Balance Training: Balance training is recommended during all stages of rehabilitation for example standing exercises initiated on one leg should be done and progressed towards maintaining balance on an unstable surface like a wobble board with both legs and then the injured foot and with the slow removal of hands support.
Plyometric Training: Plyometric training involves high-intensity exercises such as include jumping, running and cutting drills, etc.

The patient is advised to practice foot and ankle functions and tape or brace should be used during high-intensity exercises for protection and support.