Ankle Sprain: Revisiting a Common Injury (Part I)
By Bryan Dorrel, Associate Professor
Tarleton State University
An ankle sprain is defined as a rip, stretch or tear of connective tissues holding the foot to the lower leg. Connective tissues are structures that hold or bind the body together and include ligaments, tendons, fascia, cartilage, bone and blood. Specifically, ligaments hold our bones together and are most associated with a sprain1. The most common mechanism for an ankle sprain is supination, which is a combination of motions in which the foot is planted downward with the sole of the foot rolling in.2
To determine the severity of an ankle sprain athletic trainers asses all potential effects and grade the severity of the sprain. First degree sprains are seen as minor, 2nd degree as moderate and 3rd degree as severe. Keep in mind that when we sprain an ankle, the injury is hardly isolated to only the surrounding connective tissues and ligaments. Deep within the affected area we damage vascular structures, muscles, tendons, and nerves. Just for a moment, think about all the potential effects one could have from a basic ankle sprain.
· Joint instability (looseness in the joint) – damaged ligaments no longer hold the bones together effectively. The joint feels loose or unstable to the athlete or athletic trainer conducting the evaluation. This can become a chronic problem resulting in abnormal motion occurring within the joints of the ankle and it can produce long term effects to an athlete. As abnormal motion occurs with the ankle joint, cartilage is worn away exposing bone surfaces which can accelerate joint degeneration. Joint instability is now widely accepted as one of the primary causes of osteoarthrits (joint degeneration).3
· Swelling – damaged vascular structures are now bleeding into the joint space rather than being contained in the vessels or arterioles which move the blood throughout the body.
· Pain – or abnormal sensations can occur due to injury of nerve tissue found in the injured structures. Never underestimate the effect pain can have on human function. In a study examining the effects of pain on knee joint movement, function and muscle activity surrounding the joint, researchers determined that a simple injection of saline solution to produce pain was capable of creating significant biomechanical changes in knee joint function.4 Research suggests that the induced pain created significant reduction in quadriceps function, EMG average amplitude (used to measure muscle contraction intensity), and the dynamics of the knee joint.4 Besides inhibiting the quadriceps was the additional reduction of hamstring function even though not directly injected with saline. Researchers concluded that pain was capable of altering joint function and potentially joint stability.4 In a systematic review and meta-analysis of bilateral balance impairments after lateral ankle injury, researchers have determined that balance is significantly affected (p<.0001) on both sides of the body following acute ankle sprain, but not with chronic ankle instability.5 A multitude of research exists that demonstrates muscle and movement control changes with acute or chronic pain.4,6-9 In the presence of pain, tissue will biomechanically alter in an unpredictable pattern10 and we should not expect the body to function as it once did, even with something as common as an ankle sprain.
· Loss of motor function (movement) – this would include range of motion, muscle function & strength
· Loss of proprioception – the unconscious feedback of movement & spatial awareness coming from inside the body itself. In the human body, internal information like balance, pressure, and body control are detected by specialized sensory nerves called proprioceptors found in the joints & inner ear. This information is relayed to the brain so that the body can make an appropriate response to something such as a complex movement or loss of one’s balance.11
· Bone defect – with any musculoskeletal injury, a boney defect such as a fracture or bone bruise is always possible.
Sometimes we make the mistake of assuming that an athlete simply needs to tolerate discomfort in order to play. In doing so we are grossly underestimating the complexity of the human body and the effect musculoskeletal injury has on an athlete. Pain and discomfort are minor in comparison to the potential effects of joint instability, altered biomechanical function of tissues and diminished athletic performance.
Bryan Dorrel can be reached at bdorrel@gmail.com