{Reference Type}: Journal Article {Title}: A three-headed plantaris muscle fused with Kaplan fibers: potential clinical significance. {Author}: Maślanka K;Zielinska N;Paulsen F;Niemiec M;Olewnik Ł; {Journal}: Folia Morphol (Warsz) {Volume}: 0 {Issue}: 0 {Year}: 2023 Nov 14 {Factor}: 1.195 {DOI}: 10.5603/fm.95513 {Abstract}: The plantaris is a short, small muscle that usually originates at the popliteal surface of the femur and has a long, thin tendon that typically inserts into the calcaneal tuberosity. Its role and degree of development have been objects of debate for years. Some authors consider it a vestigial muscle while others believe it is a process of its development. The clinical significance of plantaris muscle is usually related to its morphological variation, which is common and well described in the literature. These variations are often a risk factor for many ailments and disorders. We would like to present another, very rare case of three-headed plantaris muscle (fused with distal Kaplan fibers), and consider what clinical implications it may have.