Every Major Running Injury — Covered.

Shin splints — clinically known as medial tibial stress syndrome (MTSS) — is an overuse injury where the connective tissue and bone along the inner edge of the tibia become inflamed and tender. It sits on a continuum: pushed too far, MTSS becomes a tibial stress reaction, then a true stress fracture.

Achilles tendinopathy is degeneration and disorganization of the Achilles tendon fibers from chronic overload. It's not a classic 'inflammation' injury — the modern model is that the tendon adapts poorly to load, thickens, and becomes painful. Two main types: insertional (at the heel) and mid-portion (2-6 cm above the heel).

IT band syndrome (ITBS) is irritation of the tissue at the outside of the knee where the iliotibial band crosses the femur. The band itself doesn't 'tighten' — the underlying tissue gets compressed and inflamed from repeated knee flexion under poor hip control.

Plantar fasciitis is degeneration of the plantar fascia — the thick band of tissue along the bottom of the foot from heel to toes. Like Achilles tendinopathy, it's a load tolerance problem more than an inflammation problem.

Patellofemoral pain syndrome (PFPS) — 'runner's knee' — is pain around or behind the kneecap from poor tracking and load distribution at the patellofemoral joint. It accounts for roughly a quarter of all running injuries.

A hamstring strain is a tear in the muscle fibers of the biceps femoris, semitendinosus, or semimembranosus. Grades range from I (microtears) to III (complete rupture). Distance runners typically get low-grade chronic strains; sprinters get sudden high-grade tears.

A stress fracture is a small crack in a bone that develops when bone breakdown outpaces bone remodeling. Common sites for runners: tibia, metatarsals (especially the 2nd and 3rd), navicular, and femoral neck. Some — femoral neck and navicular — are 'high-risk' and require careful management.

A calf strain is a tear of the gastrocnemius or soleus muscle fibers. Gastroc strains tend to be sudden and painful ('feels like being kicked'); soleus strains develop more gradually and are sometimes confused with shin splints or Achilles issues.

A hip flexor strain involves the iliopsoas or rectus femoris — the muscles that lift the leg forward. Most common in sprinters, hurdlers, and runners who spike speed work, but also seen in distance runners with high mileage and lots of sitting outside of training.

Running-related lower back pain is usually mechanical — muscle, joint, or disc irritation from poor core control, repetitive impact, and accumulated training load. True structural causes (stress reaction of the pars, disc herniation) exist but are less common.

Patellar tendinopathy — 'jumper's knee' — is degeneration of the patellar tendon just below the kneecap. Common in jumpers and sprinters; in distance runners it usually shows up after spikes in hill work or speed.

Piriformis syndrome is irritation or compression of the sciatic nerve as it passes near the piriformis muscle deep in the glute. Symptoms can mimic sciatica from a lumbar disc, which makes diagnosis tricky. True piriformis syndrome is overdiagnosed; deep gluteal pain is often actually proximal hamstring tendinopathy or low-back referral.