Multiple variations of extensor muscles on one hand are very rare. We found in the right hand: 1. M. extensor digitorum was split into two separate muscles; 2. M. extensor pollicis et indicis; 3. M. extensor indicis et digiti medii. All their tendons were in the 4th compartment. The extensor digiti minimi muscle showed a doubled tendon. Besides, we classified the course of tendons in the fourth compartment into a superficial and a profound level. Moreover, we defined the innervation by dissecting the deep branch of the radial nerve having direct branches into the muscles. In our case the extensor pollicis longus muscle was double innervated by a branch of the deep radial nerve and also by a small branch of interosseus antebrachii posterior nerve.
