distinguishable between the wasted upper deltoid and wasted humeral muscles. Shoulder weakness and pain can in turn lead to shoulder instability, such as recurrent dislocation, subluxation, or downward translation of the humeral head. Also affected is the chest, particularly the parts of the pectoralis major muscle that connect to the sternum and ribs. The part that connects to the clavicle is less often affected. This muscle wasting pattern can contribute to a prominent horizontal anterior axillary fold. Beyond this point the disease does not progress further in 30% of familial cases. After upper torso weakness, weakness can "descend" to the upper arms (biceps muscle and, particularly, the triceps muscle). The forearms are usually spared, resulting in an appearance some compare to the fictional character Popeye, although when the forearms are affected in advanced disease, the wrist extensors are more often affected. Lower body and trunk After the upper body, weakness can next appear in either the pelvis, or it "skips" the pelvis and involves the tibialis anterior (shin muscle), causing foot drop. One author considers the pelvic and thigh muscles to be the last group affected. Pelvic muscle weakness can manifest as pelvic tilt, causing the hips to be held in slight flexion. Pelvic weakness can also cause a Trendelenburg's sign. Weakness of the back of the thigh (hamstrings) is more common than weakness of the front of the thigh (quadriceps). Weakness can also occur in the abdominal muscles and paraspinal muscles, which can manifest as a protuberant abdomen and lumbar hyperlordosis. Abdominal weakness can cause inability to do a sit-up or the inability to turn from one side to the other while lying on one's back. Of the rectus abdominis muscle, the lower portion is preferentially affected, manifesting as a positive Beevor's sign. In advanced cases, neck extensor weakness can cause the head to lean towards the chest, termed head drop. Non-muscular The most common non-musculoskeletal manifestation of FSHD is abnormalities in the small arteries (arterioles) in the retina. Tortuosity of the arterioles is seen in approximately 50% of those with FSHD. Less common arteriole abnormalities include telangiectasias and microaneurysms. These abnormalities of arterioles usually do not affect vision or health, although a severe form of it mimics Coat's disease, a condition found in about 1% of FSHD cases and more frequently associated with large 4q35 deletions. High-frequency sensorineural hearing loss can occur in those with large 4q35 deletions,