By Harry A. Bade, III, MD, FACS
Shin splints, or medial tibial stress syndrome, is a term used by athletes to describe anterior shin pain involving the anterior proximal or distal medial aspects of the leg.
Posterior shin splints involve the posterior tibia muscle and tendon and occur one to six inches above and slightly posterior to the medial malleolus or medial ankle bone. In younger runners, it usually represents either micro-tears of the muscle or tears involving the origin of the muscle fibers on the bone, which is described as periostitis.
It is frequently painful and tender both along the medial and posterior aspects of the distal tibia involving the posterior tibial tendon, and in more severe cases, the flexor digitorum longus and flexor hallucis longus tendons. The pain is more severe when rising up on the toes or everting the foot, thereby stretching the tendon myofascia muscle complex.
The first risk factor to consider is overtraining or normal training involving a younger or beginner runner. Evaluation of the runner’s schedule is important. This includes both the training and racing schedule shoe wear. Hyperpronation may also contribute to the problem, therefore, shoe evaluation is important. Shoes that are highly rated for control of pronation may be helpful.
The running surface should be supportive such as all weather artificial tracks or packed dirt. Avoid excessive hard and soft surfaces. General posterior stretching exercises and ice baths following running may offer some relief. They are not curative.
Excessive pronation is a contributor to this problem, therefore, orthotics to control excessive pronation or heel lifts may offer some relief. Avoid running on a canted surface because the uphill foot has excessive pronation during the full weightbearing force on the foot.
Decrease training immediately and find the distance that you can run without reproducing excessive pain. Cross-training may be an alternative to include swimming, biking and pool running. Also, physical therapy may help to include stretching, strengthening, electric stimulation and ultrasound. Appropriate anti-inflammatory medication may also be used.
Anterior shin splints involve the anterior tibial muscle and tendon and occur along the proximal anterior lateral tibia for a distance of about four to five inches. There is a higher instance of either stress fractures or compartment syndrome problems as the differential diagnosis of this overuse problem. Again, this is a soft tissue injury involving the muscular origin of the tibialis anterior muscle on both bone and periosteum.
There is usually a mechanical imbalance between the posterior and anterior muscle groups. The posterior muscle groups are usually too tight and relatively too strong. At heel strike, (initial foot contact with the ground), the anterior muscles must function to slow the forward or downward plantarflexion of the foot. This is a deceleration function. If the posterior muscle groups are too tight and strong, they will force the anterior muscles to work harder and longer to control the foot.
The second imbalance occurs during toe off when again, the anterior muscles are overused to lift up or dorsiflex the foot so it will clear the ground as the leg is brought forward. As the anterior muscle grip fatigues, it becomes dysfunctional producing over trauma or muscle micro tears/strains.
This imbalance is accentuating by running downhill, which only exacerbates the overuse on the anterior leg muscles. Running on harder surfaces is also a more frequent problem with anterior shin splints.
Overtraining and improper shoes also can accelerate this problem. Shoes must have appropriate shock absorption and again, overtraining only makes the situation worse. The muscles naturally become more fatigued and dysfunctional, causing more injury.
The treatment is similar to that for posteromedial shin splints. It should also include stretching the posterior muscles of the leg and calf to include the hamstrings, changing shoes to a more shock absorbing or soft shoe as compared to a shoe that controls pronation, and avoidance of downhill running and running on hard concrete-like surfaces.
If symptoms persist, running should be decreased or stopped. Also, appropriate medical evaluation to rule out stress fracture and anterior compartment syndrome should be considered. Anti-inflammatory medication also may be used along with physical therapy.
These conditions are common in high school runners and early recognition and treatment is essential in maintaining the athlete’s ability to compete.