Biceps tendonitis is one of the common causes of shoulder pain, mostly seen in middle-aged people. It manifests as shoulder pain, which is aggravated by shoulder joint activity and relieved by rest, and is more pronounced at night. The main clinical features are pain in the intertrochanteric groove and limitation of shoulder joint movement. If left untreated, it may develop into frozen shoulder. Biceps tendonitis is a degenerative disease caused by repeated friction of the biceps tendon in the humeral intertrochanteric groove during shoulder joint activity, resulting in congestion, edema, adhesions, fibrosis, and thickening of the tendon sheath, resulting in impairment of the sliding function of the tendon sheath and pain, pressure pain, and limitation of shoulder joint activity in the intertrochanteric groove. The upper part of the biceps has two heads, the long-headed tendon and the short-headed tendon, both of which are prone to tendinitis. Biceps tendonitis is usually due, at least in part, to impingement of the biceps tendon at the rostral arch of the acromion. Biceps tendonitis is acute and usually occurs after overuse or misuse of the shoulder joint, such as practicing above-head tennis serves, excessive golf swings, riding on a bus, holding the handle above the head while standing, and sudden twisting of the arm when the car makes a sharp turn. The muscles and tendons of the biceps are susceptible to trauma, abrasion, and avulsion. If the damage is severe, the tendons of the long and short heads of the biceps will rupture and the patient will not be able to show the bulge of the biceps after contraction. The pain of biceps tendinitis is characterized by constant and severe pain. The pain is located over the biceps groove in the front of the shoulder. Along with the pain, the joint may have a sensation of entrapment. Patients often have a combination of severe sleep disturbances. The patient may attempt to pinch the swollen tendon through an internal rotation movement of the humerus, thereby moving the biceps tendon from under the rostral acromion arch. Patients with biceps tendinitis will have a positive response to testing by the Yergason test. The test involves flexing the patient’s elbow at a constant angle and producing pain when the forearm is subjected to an active posterior rotation movement against resistance. In addition to pain, patients with biceps tendinitis often experience a progressive loss of functional capacity due to reduced range of motion in the shoulder, making it difficult to perform simple daily activities such as combing one’s hair, tightening one’s bra, or raising one’s hand above one’s head. If this continues, muscle atrophy may occur, resulting in a frozen shoulder. For the treatment of this disease, initial non-surgical treatment can be effective, such as acupuncture, reduction of hand activities, external application of herbal safflower oil and other blood-activating drugs to reduce swelling, and the application of plasters. Local closure therapy is more effective for the early treatment of the disease, but local closure therapy should not be used repeatedly. The minimally invasive treatment of small needle knife, through the loosening of adhesions to soft tissues to achieve therapeutic effects, fast results, no side effects, worth promoting the application. For particularly stubborn cases, surgical treatment is required. The method is to cut the long head tendon of the biceps below the inter-nodal groove and suture the distal severed end to the short head tendon of the biceps or fix it to the humerus to eliminate the friction of the tendon and relieve the symptoms. However, the percentage of this particular case is very small.