Ligamentum nuchae (pars funicularis)
The nuchal ligament is not a muscle but a critical elastic structure. It consists of two parts: the funicular part (a thick elastic cord running from the external occipital protuberance at the poll to the withers) and the lamellar part (paired sheet-like portions that extend from the funicular cord down to the spinous processes of the cervical vertebrae, typically C2–C5 or C2–C6 in modern horses). The funicular part continues caudally as the supraspinous ligament. Because it is elastic, it passively supports the weight of the head (roughly 40 kg or more) without constant muscular effort. It also stores and returns energy during head and neck oscillation at the walk and trot. This is one reason a horse can stand with its head up while resting.
Origin: External occipital protuberance (poll)
Insertion: Summit of the supraspinous ligament at the withers (spinous processes of T3-T5)
Action: Passive support of the head and neck; elastic energy storage during locomotion; connects head-neck pendulum to back movement
Innervation: None (ligament — not innervated)
Nuchal bursitis (poll evil) can occur at the poll. Degeneration or mineralization of the lamellar portion can occur, especially around C2–C3. Displacement or injury of the funicular part can contribute to neck stiffness or abnormal head carriage. The structure is not innervated itself but is closely associated with bursae and surrounding soft tissues.
## Overview Nuchal ligament desmopathy encompasses degeneration, mineralization, or tearing of the nuchal ligament, especially near its insertion at the withers or attachment to the axis. It can prod
## Overview Bursal inflammation at the poll (poll evil when it becomes chronic and fistulous) is inflammation of the cranial nuchal bursa that lies between the nuchal ligament and the atlas. Early di
Persistent reluctance to lower or flex the neck, or a hard swelling at the poll, should be evaluated. Balanced work and correct head carriage help maintain normal function of the nuchal ligament and associated muscles.
## Overview Nuchal ligament desmopathy encompasses degeneration, mineralization, or tearing of the nuchal ligament, especially near its insertion at the withers or attachment to the axis. It can produce pain over the poll or withers and resistance to flexion. Palpable thickening may be present. Radiographic mineralization is common and not always significant. ## Causes Chronic strain or acute trauma. ## Diagnosis Clinical examination, radiographs, and ultrasound. ## Treatment Conservative management for most cases. Surgery is rarely indicated. ## Recovery and Prognosis Generally good. ## Prevention Balanced neck use and trauma avoidance. Signs include: pain over the poll or withers; resistance to flexion; palpable thickening; radiographic mineralization (may be incidental)
## Overview Bursal inflammation at the poll (poll evil when it becomes chronic and fistulous) is inflammation of the cranial nuchal bursa that lies between the nuchal ligament and the atlas. Early disease produces painful swelling at the poll; if the bursa ruptures or becomes infected, draining tracts develop. Historically the condition was linked to Brucella abortus, although other bacteria and trauma are now more commonly implicated. ## Causes Direct trauma, penetrating wounds, and extension of infection from adjacent tissues are the usual modern causes. Brucella species remain a concern in endemic areas and pose a zoonotic risk. The evidence is limited on the current prevalence of Brucella-associated cases in many countries. ## Diagnosis Painful swelling at the poll, reluctance to flex the neck, and, in advanced cases, draining tracts are characteristic. Ultrasound and fluid analysis confirm bursal involvement and infection. Culture, including specific testing for Brucella when indicated, guides therapy. ## Treatment Early aseptic cases may respond to rest, anti-inflammatories, and drainage. Septic or fistulous disease requires prolonged antibiotics, surgical debridement, and sometimes removal of necrotic nuchal ligament. Brucella-positive horses need special public-health precautions. ## Recovery and Prognosis Prognosis is fair for early, non-infected cases and guarded once fistulas and bone involvement develop. Significant scarring can remain. ## Prevention Avoidance of poll trauma and prompt wound care reduce risk. Biosecurity measures limit Brucella exposure in endemic regions. Signs include: painful swelling at the poll; reluctance to lower or flex the neck; heat; draining tracts in chronic cases; fever if septic
Nuchal bursitis (poll evil) can occur at the poll. Degeneration or mineralization of the lamellar portion can occur, especially around C2–C3. Displacement or injury of the funicular part can contribute to neck stiffness or abnormal head carriage. The structure is not innervated itself but is closely associated with bursae and surrounding soft tissues.
Persistent reluctance to lower or flex the neck, or a hard swelling at the poll, should be evaluated. Balanced work and correct head carriage help maintain normal function of the nuchal ligament and associated muscles.
See the Nuchal Ligament (Funicular Part) on our interactive 3D horse model. Open 3D Model