Intramuscular Tendon Pathology

Clinical Presentation and Diagnosis

The American Academy of Family Physicians notes that intramuscular tendon pathology represents degenerative changes with collagen disorientation and fiber separation, not acute inflammation, as evidenced by studies 1, 2
Patients with intramuscular tendon pathology typically present with insidious onset of load-related localized pain that coincides with increased activity or new training demands, described as "sharp" or "stabbing" in quality, according to the American Academy of Family Physicians 1, 3
Physical examination findings include well-localized tenderness on palpation that reproduces the pain experienced during activity, pain reproduced by physical maneuvers that simulate tendon loading, swelling, asymmetry, and erythema, as well as muscle atrophy and limited range of motion in chronic cases, as reported by the American Academy of Family Physicians 1, 3, 4
Ultrasonography can demonstrate tendon thickening and heterogeneous echogenicity, while MRI is sensitive (95%) and specific (95%) for detecting tendon degeneration, tears, and chronic tendinopathy changes, according to the American Academy of Family Physicians 1

The American Academy of Family Physicians advises against misdiagnosing intramuscular tendon pathology as inflammatory "tendinitis", as most patients have chronic degenerative tendinosis, not acute inflammation, which can lead to overreliance on anti-inflammatory medications that provide only short-term relief without addressing the underlying degenerative process 2, 5, 6