Anatomy
The calf muscles are divided into 3 muscle groups (muscle compartments) by strong muscle membranes (fascia). An anterior muscle compartment (comprising the flexor muscles of the foot, the extensors), an external (lateral) muscle compartment (comprising the peroneal muscles) and a posterior muscle compartment (comprising the extensor muscles of the foot, the flexors).
See image of Tibialis periostitis (shin splints – fibula)
The large posterior muscle group’s muscle sheath attaches to the inner edge of the tibia, while the anterior muscle group’s muscle sheath attaches to the outer edge of the tibia.
See image of Tibialis periostitis (shin splints – lower leg)
Cause
If the intensity of exercise increases too rapidly with repetitive, repetitive loads (running, jumping, dancing) that exceed tissue strength, overload-related microscopic lesions and ”inflammation can occur at the attachment of the muscle membrane on the edge of the tibia. This condition is most common in runners who frequently change running surfaces. Pronounced pronation (where the foot ‘falls’ inwards when landing during running) is thought to increase the risk of internal (medial) shin splints.
Symptoms
Pain on the inner or outer edge of the tibia. Aggravated by pressure and strain. Pain on the inner edge of the tibia is aggravated by stretching the ankle (flexion) against resistance, and pain on the outer edge of the tibia is aggravated when the foot is bent up against resistance (extension). The pain is most often localised to the lower 1/3 of the tibia and is often bilateral.
Examination
In mild cases, the diagnosis is usually made on clinical examination alone, where the pain is localised directly on the edge of the tibia. If in doubt about the diagnosis, it is advisable to be examined by a relevant professional who may supplement with imaging studies (X-ray, ultrasound or MRI scan).
Treatment
Treatment includes relief from pain-inducing activity, stretching and slowly increasing rehabilitation within the pain threshold. Good shock-absorbing soles in shoes are essential (Deshmukh NS, Phansopkar P. 2022).
Complications
If the progress is not smooth, a medical assessment should be carried out to ensure the diagnosis is correct and that there are no complications such as fatigue fractures and musculoskeletal syndrome.
