Feature of the Month
Ankle Sprain/Twisted Ankle
Ankle sprains are one of the most common sport-related injuries and usually involve the ligaments on the outside of the ankle. Ligaments are structures that connect bone to bone. Ligaments on the outside of the ankle joint attach the outer leg bone, the fibula, to two ankle bones. If the ankle turns inward as a result of an injury, tearing and stretching of these ligaments may occur. Ankle sprains are common among athletes who participate in sports involving a lot of jumping and running such as basketball, volleyball, football, and soccer. For example, a basketball player jumping up for a rebound may land awkwardly on an opponent's foot, twisting the ankle inward (inversion sprain) (Figure 1). The injured basketball player may have heard a popping or cracking noise during the fall. Typically the ankle swells, and depending on the severity of the injury, crutches may be necessary.
An understanding of the anatomy and biomechanics of the ankle is necessary in order to properly diagnose and treat the injured ankle.
Anatomy and Biomechanics of the Ankle Joint
The ankle joint, which connects the lower leg to the foot, is stabilized primarily by its bones and ligaments. This discussion will focus on the ankle joint and the ligaments, muscles, and tendons located on the outside of the ankle.
The ankle joint is actually two joints. The first, the talocrural joint, connects the bottom of the two leg bones, tibia and fibula, with the top of an ankle bone, the talus (Figure 2). The talocrural joint allows for movement of the ankle in dorsiflexion (when the toes point upward) and plantar flexion (when the toes point downward) (Figure 3). The second joint, the subtalar joint, connects the bottom of the talus with the calcaneus (heel bone) (Figure 4). The subtalar joint allows for movement of the ankle in eversion (tilting of the the ankle outward) and inversion (tilting of the ankle inward) (Figure 5). During normal movement patterns, the ankle joint can absorb the shock associated with the foot striking the ground surface without placing a significant strain on the ligaments surrounding the ankle joint. However, in the case of an inverted ankle sprain, the ligaments on the outside of the ankle are subjected to extreme forces, leading to tearing and/or stretching of these ligaments.
Two main ligaments, the anterior talofibular ligament and the calcaneofibular ligament, located on the outside of the ankle, are important for providing stability to the ankle joint during a normal range of motion. These ligaments also attempt to protect the joint during abnormal inversion of the ankle (Figure 6). The calcaneofibular ligament originates from the lateral malleolus (the bony protrusion on the outside of the ankle) which then crosses the ankle joint and attaches to the outside of the calcaneous. The talofibular ligament also originates from the lateral malleolus, crossing the ankle joint and inserting onto the neck of the talus. Injury of these ligaments (typically accompanying an inversion sprain) without proper post-injury rehabilitation may lead to chronic instability of the ankle joint and impaired athletic performance.
The dynamic stabilizers of the ankle joint, which protect the ankle during movement, are the muscles and tendons. Muscles generate force through three types of dynamic contractions: concentric, eccentric and isometric. A concentric contraction involves shortening of a muscle to generate a particular motion; an eccentric contraction is a controlled lengthening of a muscle utilized to decelerate a particular motion; and an isometric contraction involves neither elongation nor shortening of muscles, and is useful in the initial stages of a rehab program.
To illustrate these different contractions, we will use the bicep muscle as an example. When lifting a dumbbell during a bicep curl, the bicep muscle concentrically contracts. As the dumbbells are lowered, the bicep muscle attempts to decelerate the weight by eccentrically contracting. An example of an isometric contraction of the bicep would be having the patient attempt to flex the arm against a stable resistance; the muscle fibers of the bicep would activate without shortening or elongating.
Tendons are nonelastic structures that attach muscles to bone and transfer forces generated by the attaching muscle across a joint--in this case, the ankle joint. The peroneus longus and peroneous brevis muscles are located on the outside of the leg, and their tendons pass behind the lateral malleolus. The peroneous longus tendon travels diagonally underneath the foot, inserting onto two bones near the big toe, while the peroneus brevis tendon inserts onto an outgrowth of bone below the baby toe (Figure 7). When the peroneus muscles contract concentrically, this causes the ankle to turn outward and downward. An eccentric contraction of the peroneus muscles would act to decelerate the ankle from turning inward and may help in preventing or decreasing the severity of an inversion sprain.
Rehabilitation of an Ankle Sprain
There are 3 grades of an ankle sprain. A Grade 1 sprain involves minimal damage to the ligaments, minimal pain during weight bearing, and no swelling. A Grade 2 sprain involves moderate damage to the ligaments, pain during weight bearing that may require crutches for ambulation, and swelling surrounding the ankle joint. A Grade 3 sprain involves severe damage to the ligaments, necessitating crutches for ambulation, and with profuse swelling surrounding the ankle joint.
Treatment for an Ankle Sprain at Dubin Chiropractic:
A. If the patient cannot bear weight on the injured ankle after a Grade 2 or Grade 3 sprain, and there is tenderness extending around the lateral malleolus, a fracture of the lateral malleolus bone must be ruled out with x-rays before treatment begins.
B. After ruling out a fracture of the ankle, weight bearing on the injured ankle should commence as tolerated with or without crutches. An ankle support should be worn to protect the ankle from twisting in.
C. Steps to minimize swelling are very important. The patient is instructed on ice therapy: 20 minutes on and 1 hour off, with reapplication as tolerated. Non-steroidal anti-inflammatory drugs are often useful as well.
D. Adjustments to the joints in the ankle and foot, soft tissue procedures applied to the muscles surrounding the ankle, and ultrasound/electric muscle stimulation combotherapy would be utilized to free up soft tissue motion and joint motion and decrease healing time.
E. Range of motion exercises are necessary for proper re-strengthening of the joint area. These exercises involve eversion, dorsiflexion, and plantarflexion. Stationary cycling, while stressing dorsiflexion and plantarflexion of the ankle, can maintain cardiovascular conditioning as well as restore range of motion.
F. Flexband(R) exercises are quite effective and are used to stretch the achilles tendon, strengthen the muscles that evert the ankle (peronei muscles), and strengthen the muscles on the front of the leg that dorsiflex the foot (tibialis anterior and extensor muscles) (Figures 8A, 8B, and 8C). Heel raises can strengthen the posterior calf muscles.
G. Proprioception training, retraining neurological responses of the muscles, is done with the wobble board and balance disc cushion (Figures 8D & 8E). The slide board and jumping rope are also useful proprioceptive training devices.
H. When the patient can walk without a limp, it is usually acceptable to start straight-ahead running. The patient may progress to more advanced agility drills as stability and confidence in the ankle increases.
I. Injured athletes can return to play when they can conduct full active and passive range of motion of the ankle; when the strength of the injured ankle is comparable to the non-injured ankle; when they can conduct the movements of their particular sport with minimal or no pain; and when and they are psychologically prepared to participate in their sport.
J. If conservative measures fail, surgical correction should be considered
For more information or to schedule an appointment with Dr. Dubin, call 617-471-2444.
Before beginning any rehabilitation program, consult with a physician.