Arm muscle strains generally need 3-4 weeks to heal themselves, but there are many arm muscles, need to be decided according to the specific circumstances, as follows: First, localized tendon strains: if less than 50% of the injury, such as tendon injuries, most of them can be self-healing, if the tendon injury > 50% or ligament injuries > 50%, this time the need for surgical treatment. The specific self-healing time of local injury is related to the part, 1, if it is shoulder injury, such as supraspinatus or other rotator cuff tear, generally rest for 4-6 weeks, sometimes need to be fixed with external fixator or other auxiliary support. 2, if it is biceps tendon, most of the tendon can be self-healed in about 3 weeks, but when it is self-healed, it is generally necessary to take therapeutic measures, such as infrared ray, microwave, intermediate frequency physiotherapy measures for adjuvant treatment. Measures for auxiliary treatment, at the same time, the external application of cream; Second, tendon tear: If it is a rupture, such as supraspinatus or infraspinatus, other rotator cuff tear, biceps tendon tear, or elbow joint medial and lateral collateral ligaments of the tear, carpal deltoid ligament tear, if these ligaments and muscles are more obvious tear, can not be self-healing, most often need to be immobilized, and even need to be treated surgically. If there is a complete tear in any of these areas, most of them will require surgical treatment. So depending on the muscle injury, different measures have to be taken. If it is just a strain, no obvious tear, usually 3-4 weeks can be self-healing, this self-healing is not completely regardless of it, need to carry out some of the treatment, such as partial tear, when the tear or strain cold compress, later immobilization, after 4-6 weeks need to carry on the function of the rehabilitation. If the tear is very obvious, this time must go to a specialized hospital, the specialist doctor for diagnosis, to clarify the specific cause, to determine whether there is a need for further treatment, more critical.