A fibro-osseous tunnel located on the palmar aspect of the equine carpus that contains the carpal sheath, superficial and deep digital flexor tendons, associated check ligament structures, and the median neurovascular bundle. Disorders of this region include carpal canal syndrome, retinacular restriction, tendon injuries, and osteochondromas. These conditions are important causes of forelimb lameness that often require ultrasonographic evaluation and, in some cases, tenoscopic intervention.