The tendon is composed of collagen fibers, which do not have the ability to contract, and its role is to transmit the contraction force of the muscle to the bone tissue. The tendon fibers are corrugated at rest and disappear when stretched. Microdamage to the collagen fibers can occur when overstretched, and even tendon rupture can occur. What are the examination methods for the slight absence and subsidence of the muscle belly and tendon connection that can be felt locally? 1.Magnetic resonance imaging (MRI) Magnetic resonance imaging (MRI) has diagnostic significance for lesions of the nervous system, spinal cord and spine, cardiac vessels, abdominal and pelvic organs, and soft tissue lesions of joints. MRI, also known as magnetic resonance imaging, uses the principle of nuclear magnetic resonance to detect the electromagnetic waves emitted through an applied gradient magnetic field, whereby the internal structure of an object can be mapped. 2.Electromyography The functional state of peripheral nerves, neurons, neuromuscular junction and muscles themselves can be determined by electromyography. Electromyography is a means of aiding in the examination of disease through electromyography. It is a method of recording the electrical activity of a muscle at rest or during contraction by means of an electronic instrument and of checking the excitation and conduction of nerves and muscles by means of electrical stimulation. This test can determine the functional status of peripheral nerves, neurons, neuromuscular junction and muscles themselves. 3.High-frequency ultrasound The sound waves that vibrate 20,000-1 billion times per second and cannot be heard by the human ear are called ultrasound. The use of the physical properties of ultrasound for diagnosis and treatment of an imaging discipline, called ultrasound medicine. Its wide range of clinical applications has now become an indispensable diagnostic method in modern clinical medicine. Muscle injuries can generally be made by physical examination. However, it is sometimes difficult to determine the degree of muscle rupture. High-frequency ultrasound or MRI has an auxiliary diagnostic effect on the determination of the degree of muscle rupture and can be used as a follow-up means.