What Is an Extensor Muscle?

The extensor is a kind of skeletal muscle according to its function, which usually refers to the kind of muscle that can cause skeletal extension (strecku-ng) at the joint.

The extensor is a kind of skeletal muscle according to its function, which usually refers to the kind of muscle that can cause skeletal extension (strecku-ng) at the joint.

Muscles that straighten limbs or other parts of the body. Its tendon often passes through the apex of the joint. It usually crosses behind the crown (frontal) axis of the joint, such as the triceps. The exception is the knee and ankle joints of the lower limbs, where the extensor muscles cross the front of the coronary axis, such as the quadriceps and long flexors.

Chinese name

Extensor

Foreign name

extensor

Belong to

Skeletal muscle

Category

joint

Extensor related anatomy

Morphology of the total extensor tendon

Radial wrist long extensor

The radial long wrist extensor muscle starts muscularly from the lower part of the upper humerus and the bare upper condyle, the outer side of the small head of the humerus, and the scaphoid fascia, accounting for 92.5%, and 7.5% has a small amount of tendon fibers in the lower ankle . The starting point is triangular, narrow upper and lower, the starting length is 30.4 ± 11.3 (12,75) mm for adults and 29.8 ± 7.9 (20,46) mm for children. In the upper limbs of the gross specimens studied, this muscle has muscle fibers that originate from the anterior side of the scaphoid aponeurosis, and no one originated from the deep fascia and lateral muscle space.

2. Radial wrist short extensor

The radial short wrist extensor muscles tendon "scaphoid" from the most prominent part of the lateral humerus, below the lateral superior malleolus, and the anterior lateral surface of the small head of the humerus. Bare outside the humerus. Among them, 12.5% have tendon fibers from the circular ligament, and the superficial layer of individual superficial muscles have muscle fibers from the scaphoid aponeurosis. This fascia is shaped like an inverted boat, and the mediastinum at the bottom of the boat is the radial wrist length The distance between the extensor and the total extensor muscle is tendonous in the deep and membranous in the superficial, which is connected to the deep fascia of the forearm. This boat divided the bottom of the boat into two parts, front and back. The surface of the boat is close to the surface of the supinator muscle, and the proximal end is adjacent to the circular ligament of the radial head septum. The tendon fibers are arranged neatly and radiate from the proximal end to the distal end.

3. Total extensor

The total extensor is located between the short radial extensor and the ulnar extensor. In the gross specimens studied, most of the muscle fibers of this muscle started from the posterior side of the scaphoid aponeurosis. The posterior edge of the posterior muscle is more and more, the ulnar edge and the ulnar carpi extensor are growing. The radial tendon with a triangular tendon bundle connected to the scaphoid membrane of the radial wrist short extensor muscles accounts for 82.5%.

Composition and training methods of typical extensors

1. Dorsal extensor is a general term for large and small muscle groups that straighten the spine. The main function is to stretch the waist, back, and neck. Exercises for stretching and overextending the extensor muscles are conducive to: improving the muscle strength and endurance of the extensor muscles; enhancing the local blood circulation to promote the edema subsidence; increasing the straightening movement is conducive to the recovery and maintenance of the spinal physiology; Flexibility prevents waist sprains; balance the strength of the trunk flexors and extensors and maintain good posture. In particular, the contraction of the muscle rhythm in the straightening movement of the waist makes the "muscle pump" promote the return of small veins and alleviate the effects of local anesthesia and edema. Active exercise improves strength and endurance and promotes blood circulation.

2. Back extensor exercise method: lying on a flat bed or a flat surface, both lower limbs flexion and flexion, generally at 60 ° ~ 130 °, both elbows and headrest feet on the bed for support (five-point style), OK Raise your hips, exercise your abdomen, and try your best to lift your abdomen, 30 to 50 times / minute, do it rhythmically, once in the morning and evening.

Exercises are carried out step by step, starting with moderate small activities to prepare for warm-up for 1 minute. Morning and evening exercise for 5 minutes in week 1, morning and evening exercise for 10 minutes in week 2. Week 3 morning and evening 20 minutes. Practice for 20-30 minutes morning and evening after 3 weeks. Those who can't complete the exercise for a period of time can practice in the gap. It is necessary to ensure that the accumulated exercise time reaches the specified requirements. Week 3 generally requires> 10 minutes to rest. Control the frequency yourself. For those with severe back pain, steroidal analgesics can be taken orally for 5 to 7 days, and generally can tolerate exercises.