Lateral Ankle Sprain: What Does The Research Say?


In sports, one of the most common musculoskeletal injuries is an ankle sprain. Ankle sprains are a broad diagnosis that is not specific in determining which ligaments are affected. Most commonly, the anterior talofibular ligament (ATFL) is sprained followed by the calcaneofibular ligament (CFL), through inversion of the ankle/foot.1 This is referred to as a lateral ankle sprain (LAS). In today’s post we look at the research on treatment/rehab protocols of lateral ankle sprains and return to play (RTP) measures in athletes.

Basic Healing Phases of Ligaments

Before I get started, it is important to note that nearly all musculoskeletal injuries heal with time. However, ruling out a fracture should be the first priority. There is high level of evidence to suggest the Ottawa Ankle Rules is a valid tool for ruling out fractures.8

When approaching LAS, it is important to determine (1) the severity and (2) the general healing phase of ligamentous tissue. In the early stages of ligament repair, fragile type III collagen is produced and laid down.10 This collagen provides an initial framework until type I collagen is gradually laid down starting on day five.10 Type I collagen is abundant in ligaments and functions to resist tension and stretching.10 It is important to note, until day five, putting tension on the damaged ligament will likely tear the fragile connection of type III collagen, thus disrupting proper healing.  However, when type I collagen is starting to become laid down, tension becomes an important aspect in the ligament’s healing process. Gorniak and Conrad10 say, “tension during the fibroplasia (day 5-21) and consolidation (day 21-60) phases:

  • activates fibroblast production of collagen
  • controls the direction collagen fibers are aligned
  • produces large collagen bundles
  • increases scar strength by increasing the alignment amount, size and stability of collagen
  • increases healing rate and completeness of healing.”

With that being said, ligament healing is not so black and white. It depends on many factors such as age and severity of the sprain, just to name a few. A systematic review by Hubbard2 found ankle laxity after acute ankle sprain improved over a period of 6 weeks to 1 year. Thus concluding the time needed for ligaments to heal after ankle sprains is somewhat unknown.2

What are the concerns with LAS?

When approaching LAS it may be beneficial to identify controllable risk factors for LAS. According to Kobayashi4, risk factors that had significant correlations with LAS were:

  • “Increased body mass index (BMI)
  • Slow eccentric inversion strength
  • Fast concentric plantar flexion strength
  • Decreased passive inversion joint position sense (proprioception)
  • Decreased reaction time of the peroneus brevis”

Although these risk factors correlate with ankle sprains, two of the biggest concerns with LAS is the risk of re-spraining the ankle and chronic ankle instability.7,8 In a study done by McCann5, researchers measured pain, swelling, dorsiflexion ROM, ligament laxity, and dynamic postural control 48 hours before RTP after a LAS. The average RTP time was 12.7 days.5 They found that patients had significantly greater swelling, ligament laxity, lower ROM in ankle dorsiflexion, and lower balance on the involved limb compared to the uninvolved limb.5 What does that tell us? Athletes RTP when they are not completely healed! This, in turn, could a reason why re-sprains are so common.

With that being said, let’s be realistic. Hubbard’s systematic review showed improvements in mechanical stability did not occur until at least 6 weeks to 3 months, and ligament laxity improved over a period of up to 1 year!2 When I was an athlete and sprained my ankle, there was no way I was sitting out for that long. There is a lot of pressure to perform, especially when you are trying to prove yourself. The reality is athlete’s play through injuries all the time, and rarely are they truly 100% healthy.

So what do we do about this?

To be honest, I don’t know. If I were to take a stab at it, I think athletes being proactive about their bodies will make a huge difference. Sometimes injuries happen and there is nothing that you can do to prevent it, but I look at this as a percentage game. Being proactive about your body will decrease the percentages of injuries, especially the ones that players in a specific sport are high risk for.

Therapeutic Interventions

I am not going to get into the specifics of how to treat LAS because there are many different ways to approach LAS. I am showing you the research on different methods of training and their benefit to LAS.

Immobilization & Drugs

When it comes to rehabilitation, like I previously mentioned, the majority of musculoskeletal injuries will heal with time. With that being said, since ligament healing needs time for type III collagen to be laid down there should be a phase of immobilization. This may depend on the severity of the sprain. McCann5 (study mentioned above) found that athletes who had greater swelling and balance deficits needed significantly longer immobilization time.5 This means they needed more time for the type III collagen to lay down the popper framework for the type I collagen.

Although McCann’s study and Gorniak’s book are suggesting crucial time frames for immobilization after injury, the National Athletic Trainers Association (NATA) position statement on ankle sprains suggests there is a high level of evidence suggesting functional rehab is more effective than immobilization when managing grade I and grade II ankle sprains.8 Do I think these contradict each other? Not one bit. NATA also says there is high evidence that “NSAIDs (ex. ibuprofen) taken orally or topically, reduce pain and swelling and improve function in the short-term after ankle sprains.”8

Let’s put this data together. The evidence recommends functional rehab as soon as possible. However, functional rehab too early will disrupt the healing process of ligaments because tension will break the connections of Type III collagen. Therefore, a period of immobilization is needed for proper healing. McCann showed the swelling was proportional to immobilization time.5 How do we decrease swelling so we can advance to functional rehab as soon as possible without disrupting type III collagen? Ice, rest, and NSAIDs. Ibuprofen (NSAID) can help with pain and swelling during the initial phases of LAS. Which will, in turn, lead to functional rehab quicker.

Plyometric Training vs Resistance Training

Ismail6 investigated plyometric training vs resistive exercises after acute LAS. They evaluated functional stability, strength, endurance, and balance that are often needed to prevent chronic ankle instability.6 They found both interventions improved functional ability of the ankle over six weeks.6 However, plyometric training improved functional ability more effectively than resistance training.6 With that being said, these results should be considered with caution as the study had a low sample size, and elementary data analysis.

Balance Training

A systematic review by McKeon7 looked to see if balance training was effective in reducing the risk of ankle sprain, improving outcomes after LAS, and improving outcomes associated with chronic ankle instability. As discussed previously, chronic ankle instability, and risk of re-spraining are two of the major concerns with LAS. They found strong evidence to suggest balance training can prevent LAS in those with a history of LAS (Number needed to treat in order to prevent 1 LAS: 12-44 athletes).7 For those who are recovering from LAS, there is strong evidence to suggest balance training can improve treatment outcomes and prevent the recurrence of LAS (Number needed to treat in order to prevent the recurrence of 1 LAS: 4-5 athletes).7 As it relates to balance training improving treatment outcomes associated with chronic ankle instability, there is more research that is needed.7

Return To Play Measures

When it comes to return to play (RTP) measures for LAS, there aren’t any. Tassignon3 said in a systematic review that “there are currently no published evidence-based criteria to inform RTS decisions for patients with an LAS injury.” LAS is one of the most common musculoskeletal injuries in sports, yet we do not have an evidence-based criteria for RTP. With no evidence-based criteria on RTP for LAS, Wikstrom9 found that there was also a lack of consistency and agreement among expert opinions on RTP criteria, along with a lack of outcomes with these techniques.9 With my lack of experience, and lack the of evidence I will not make suggestions regarding RTP measures. But, Adam, NBA physical therapist, made a great video on how he navigates ankle sprains. I recommend watching it.

Main Takeaways

  1. Seek medical professional (rule out fracture)
  2. Chronic ankle instability and LAS re-injury are the main concerns with LAS
  3. If you are in a sport with a high risk LAS, participating in a balance training program year-round has been shown to significantly reduce the risk of LAS
  4. There are no evidence-based criteria for RTP for LAS.

Disclaimer: I am not a licensed DPT, and have not treated anyone with a LAS. I am simply sharing what I am learning through the research. This should be read with caution and if you have LAS you should seek treatment from a medical professional.


  1. Hang B. Acute Sports- Related Lower Extremity Injuries. Clinical Pediatric Emergency Medicine. 2013;14(4):304-317. doi:10.1016/j.cpem.2013.11.002
  2. Hubbard TJ, Hicks-Little CA. Ankle ligament healing after an acute ankle sprain: an evidence-based approach. J Athl Train. 2008;43(5):523-529. doi:10.4085/1062-6050-43.5.523
  3. Tassignon B, Verschueren J, Delahunt E, et al. Criteria-Based Return to Sport Decision-Making Following Lateral Ankle Sprain Injury: a Systematic Review and Narrative Synthesis. Sports Med. 2019;49(4):601-619. doi:10.1007/s40279-019-01071-3
  4. Kobayashi T, Tanaka M, Shida M. Intrinsic Risk Factors of Lateral Ankle Sprain: A Systematic Review and Meta-analysis. Sports Health. 2016;8(2):190-193. doi:10.1177/1941738115623775
  5. McCann R, Kosik K, Terada M, Gribble P. Residual Impairments and Activity Limitations at Return to Play from a Lateral Ankle Sprain. International Journal of Athletic Therapy & Training. 2018;23(2):83-88. doi:10.1123/ijatt.2017-0058
  6. Ismail MM, Ibrahim MM, Youssef EF, El Shorbagy KM. Plyometric training versus resistive exercises after acute lateral ankle sprain. Foot Ankle Int. 2010;31(6):523-530. doi:10.3113/FAI.2010.0523
  7. McKeon PO, Hertel J. Systematic review of postural control and lateral ankle instability, part II: is balance training clinically effective?. J Athl Train. 2008;43(3):305-315. doi:10.4085/1062-6050-43.3.305
  8. Kaminski TW, Hertel J, Amendola N, et al. National Athletic Trainers’ Association Position Statement: Conservative Management and Prevention of Ankle Sprains in Athletes. Journal of Athletic Training (Allen Press). 2013;48(4):528-545. doi:10.4085/1062-6050-48.4.02
  9. Wikstrom EA, Mueller C, Cain MS. Lack of Consensus on Return-to-Sport Criteria Following Lateral Ankle Sprain: A Systematic Review of Expert Opinions. Journal of Sport Rehabilitation. 2020;29(2):231-237. doi:10.1123/jsr.2019-0038
  10. Gorniak G. Chapter 4: Tissue Mechanics. In: Gorniak G, Spine and Tissue Biomechanics. 1st ed. Bookboon, 2016: 68-81.


This site has content that is subject to my thoughts and opinion. Implement the content at your own caution as the author is not responsible for your actions. If you have pain, discomfort, or symptoms of any kind you should seek formal medical care from a medical professional.

Get In Touch


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: