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What Actually Happens During an Ankle Sprain?
Writer's Note
As a competitive runner and soccer player, I’ve seen teammates returned to the field two weeks after an ankle sprain, only to suffer recurrent roll-overs months later. I conducted this literature synthesis to investigate the disconnect between initial ligament healing and long-term sensorimotor deficits. Below is my breakdown of six key systematic reviews and prospective studies on chronic ankle instability (CAI).
1. The Moment of Injury
Lateral ankle sprains are among the most common injuries in soccer and other field sports. From the sideline, they can look deceptively simple: a quick roll of the ankle, a few minutes on the ground, and then either a substitution or a taped‑up return to play. Underneath that moment, though, is a complex interaction between ligaments, tissue healing, sensory systems, and the brain.
A lateral ankle sprain begins as a local tissue injury, but recovery can involve a much larger system: ligament healing, sensory feedback, neuromuscular control, and movement behavior. Research increasingly suggests that these systems interact, even though scientists still cannot predict exactly why some athletes recover fully while others develop persistent instability.
This feature asks:
What happens to an athlete’s ankle, movement system, and nervous system after a lateral ankle sprain, and why can the consequences extend beyond the initial injury?
Most lateral ankle sprains in sport involve the foot rolling inward (inversion) and pointing downward (plantarflexion) relative to the lower leg. This can happen when a soccer player lands on another player’s foot after a header, plants to cut and the foot slips, or lands awkwardly from a jump. The exact combination of forces and joint positions varies from play to play, but the common theme is that the load on the lateral ankle structures exceeds what those tissues can tolerate at that instant.
On the outside of the ankle, the main ligaments at risk are:
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Anterior talofibular ligament (ATFL) – commonly injured when the ankle is plantarflexed and inverted.
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Calcaneofibular ligament (CFL) – more involved when the ankle is closer to neutral or when inversion forces are larger.
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Posterior talofibular ligament (PTFL) – stronger and usually involved only in more severe injuries.
When the combination of body mass, speed, and joint position produces a torque that stretches these ligaments beyond their normal range, fibers can be strained or torn. Lower‑grade sprains may involve microscopic fiber damage and stretching; higher‑grade sprains involve more extensive disruption.
Not every ankle sprain follows the same script. Some involve more rotation, some occur in partial dorsiflexion, and some are contact while others are non‑contact. Two sprains that look similar on video can produce different patterns and severities of tissue injury.
Once ligament tissue is injured, the body initiates a biological response that unfolds over days to weeks.
Damaged fibers and small blood vessels release chemical signals that trigger inflammation. This early phase involves:
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increased blood flow
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movement of immune cells into the area
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release of inflammatory mediators
Fluid accumulates in and around the joint, leading to swelling. Swelling can increase joint pressure, change how the joint moves, and contribute to pain.
Pain arises from both mechanical and chemical sources:
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mechanical: movement or loading of the injured tissue
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chemical: sensitization of local nerve endings by inflammatory mediators
Athletes often limit how much they move the ankle, especially into inversion and plantarflexion. This can reduce range of motion in the short term. Over time, stiffness can also be influenced by protective muscle activity and changes in the joint capsule and surrounding tissues.
Tissue Healing and Remodeling
Ligament healing is a gradual process:
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Inflammatory phase – clearing damaged tissue and initiating repair.
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Proliferative phase – new collagen is laid down, initially in a disorganized pattern.
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Remodeling phase – collagen fibers gradually align more with the direction of stress, and the tissue’s mechanical properties evolve.
Even after an athlete feels “better,” the healing ligament may not have the same structure or mechanical behavior as before. That does not automatically mean the ankle will be unstable, but it is one factor in how the joint behaves after injury.
This section focuses on biology, not on specific treatments. Different rehabilitation approaches aim to influence these processes, but the underlying tissue response follows its own timeline.
A lateral ankle sprain is not only a ligament event. It can influence how the entire lower limb and movement system behave.
Pain, Movement, and Function
Pain and swelling often lead athletes to change how they move. In the days and weeks after injury, players may:
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avoid loading the injured side
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shorten stance time on the affected leg
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reduce ankle motion during walking, jogging, or cutting
These changes can be protective in the short term. In some athletes, though, altered movement patterns persist longer than the acute pain and swelling.
Range of Motion, Strength, and Balance
After a sprain, some athletes show:
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reduced dorsiflexion range of motion
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decreased strength in muscles around the ankle, such as the evertors and plantarflexors
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differences in single‑leg balance and postural control
These changes can be influenced by pain, disuse, and neural factors (for example, how effectively the nervous system activates the muscles). They do not appear in every athlete to the same degree, but they are part of the broader picture of how an ankle sprain can affect function.
To understand why an ankle sprain can have broader effects, it helps to look at proprioception—the sense of body position and movement.
Proprioception involves sensory information from:
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muscle spindles
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Golgi tendon organs
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joint and ligament receptors
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skin receptors
This information is integrated by the nervous system to create a sense of joint position and movement (kinesthesia). For the ankle, proprioception helps the brain know where the foot is in space and how it is moving, even without visual input.
Proprioception and Chronic Ankle Instability
A key question is whether ankle injuries are associated with longer‑term changes in proprioception. A systematic review and meta‑analysis by Xue et al. (2021) examined whether individuals with chronic ankle instability (CAI) show proprioceptive deficits compared with controls. Across multiple studies, people with CAI tended to demonstrate worse performance on measures such as joint‑position sense and kinesthesia than those without CAI.
The review also highlighted important limitations:
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studies used different tests and protocols
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definitions of CAI varied
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effect sizes were not identical across all tasks
Crucially, this evidence concerns chronic ankle instability, not every athlete immediately after a first sprain. The findings support an association between CAI and proprioceptive deficits; they do not prove that every ankle sprain automatically causes long‑term proprioceptive problems, or that proprioceptive deficits are the single cause of instability.
Brain and Sensorimotor Adaptations
Beyond local joint receptors, researchers have asked whether ankle injuries are associated with changes in the brain’s sensorimotor networks. A systematic review by Maricot et al. (2023) synthesized studies on brain neuroplasticity related to lateral ankle ligament injuries. The review included 20 studies, but only one involved participants with a recent lateral ankle sprain; the rest primarily examined individuals with CAI.
Many of these CAI studies reported differences in brain activation or connectivity in regions involved in sensorimotor control. At the same time, Maricot and colleagues emphasized that:
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most available evidence involves chronic conditions, not acute sprains
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study designs and tasks varied
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sample sizes were often modest
The review suggests that lateral ankle ligament injuries—particularly when instability becomes chronic—may be associated with brain‑level differences in sensorimotor processing. It does not establish that every ankle sprain “changes the brain” in a uniform way, or that these changes are the sole explanation for ongoing problems. The literature currently tells us considerably more about neuroplasticity in chronic ankle instability than about what happens in the brain immediately after a first lateral ankle sprain.
For a soccer player, the ankle is involved in almost every movement: sprinting, decelerating, landing from a header, cutting to evade a defender, and balancing on one leg while controlling the ball.
Researchers use tools such as:
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kinematics – joint angles and movement patterns
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kinetics – ground‑reaction forces and joint moments
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dynamic postural stability tests – how well an athlete controls the body after landing
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muscle activity measures – such as EMG to examine timing and amplitude of muscle activation
A systematic review and meta‑analysis by Chan et al. (2022) examined how chronic ankle instability affects lower‑extremity kinematics, dynamic postural stability, and muscle activity during unilateral jump‑landing tasks. Across the included studies, individuals with CAI often demonstrated:
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altered joint angles at the ankle and knee during landing
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deficits in dynamic postural stability
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differences in muscle activation patterns compared with controls
Similarly, Simpson et al. (2019) reviewed studies on dynamic postural stability and unilateral landing biomechanics in people with CAI. They reported that individuals with CAI frequently showed:
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poorer dynamic stability after landing
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changes in landing mechanics, such as altered joint positions or loading patterns