This study evaluates the effectiveness of pain guided early weight bearing as a means to enhance the outcome of acute lateral ankle sprain. Half of the participants will receive advice and instructions in pain guided early weight bearing plus a written home-based exercise program, while the other half will receive advice and instructions following standard operating procedures at site.

Lateral ankle sprains (LAS) is the most common injury in the active population. Not only is the injury prevalent within organized sports, but also display high prevalence in the general population presenting at the emergency departments (ED). LAS accounts for about 3-5% of all visits to the ED, but total LAS incidence rates are increasing in the general population.

Acute LAS is defined by Delahunt et al. and endorsed by the International ankle consortium as: "An acute traumatic injury to the lateral ligament complex of the ankle joint as a result of excessive inversion of the rear foot or a combined plantar flexion and adduction of the foot." The treatment of LAS in the emergency department consists of initial assessment and acute management of the injured foot, traditionally done by a physician. The typical assessment consists of ruling out severe injury, i.e. fracture, using the Ottawa ankle foot rules. The acute management of the injured ankle is typically composed of a treatment approach consisting of Rest, Ice, Compression and Elevation (RICE).

Extended Scope of Practice (ESP) physiotherapists in EDs have shown to generate high levels of patient satisfaction, reduce patient waiting times and have high clinical effectiveness, yet high quality randomized trials investigating the clinically effectiveness of ESP physiotherapy are lacking. Acute LAS is one of the most common injuries managed in EDs and poor functional status within the initial 2 weeks after injury is predictive of development of chronic ankle instability (CAI), which can be a serious barrier for future physical activity and occupational performance. Early and targeted interventions provided in the emergency department by ESP physiotherapists may therefore prove to be beneficial for the patients and the society.

The aim of this RCT is to investigate if pain guided early weight bearing provided by ESP physiotherapists is superior to advice and instructions following standard operating procedures provided by a physician in improving the selfreported functional outcome in patients with LAS.

The study hypothesis is that patients randomized to pain guided early weight bearing will improve significantly more in the lower extremity functional scale after 4 weeks than those randomized to standard care.

Inclusion Criteria:

1. A grade 1 or 2 LAS sustained within 24 hours of randomization
2. To be a minimum age of 18
3. Signed informed consent

Exclusion Criteria:

1. A grade 3 LAS injury sustained
2. Diagnosed with chronic ankle instability (CAI) on the affected limb
3. Fracture diagnosed by X-ray
4. Previous enrollment in the same study
5. Major lower limb surgery or other severe lower extremity injury in the past 3 months on the affected limb
6. Under the influence of drugs or alcohol
7. A condition that, in the opinion of the investigator, would preclude participation in the study (e.g., not having access to the internet, immobilization etc.)