Which Muscles Stretch Your Arms Over Your Head?

Many sports and daily activities require some degree of overhead reaching with your arms, such as gymnastics, volleyball or waving good-bye to someone. Various muscles in your shoulders and torso work together to perform this simple movement. Some stabilize your shoulders while others move your arms and shoulders in conjunction. Since these muscles are linked together by nerves and fasciae, an injury or lack of mobility in any muscle could limit your ability to raise your arm overhead.

  1. The Arm Lines

    • Since most muscles in your shoulders and torso work together to raise your arm overhead, they should be addressed as a group rather than individually. This idea is based on the myofascial meridian theory by massage therapist and anatomist Thomas Myers, which describes muscles and joints as a whole rather than individual parts. One such meridian is the arm lines, which refers to a group of muscles and fasciae that extends from the middle of your body -- back and chest -- through your shoulders and arms, and into your fingertips. The muscles of the arm lines move your shoulders in many directions. This includes shoulder flexion to raise your arm overhead.

    The Movers

    • Movers are muscles that produce a large amount of force and allow joints to move. These muscles tend to be large, are located toward the surface of the body and submit to voluntary contraction. This means that you can control when you want to use these muscles, according to fitness professional and CHEK practitioner Vreni Gurd. These movers include the trapezius, pectoralis major and minor, biceps brachii, rhomboids, levator scapulae and deltoids. When you raise your arm to reach for something in the cupboard, you can feel these muscles working.

    The Stabilizers

    • While the movers, as the name would suggest, move your shoulders, your stabilizers hold your shoulder joints in place, maintaining the proper axis of rotation during movement at the joint. Unlike movers, these muscles tend to be small, are closer to the joint and anticipate movement; they contract automatically before the joint moves. The stabilizers in your shoulders include your rotator cuffs, surpraspinatus, infraspinatus, teres minor and subscapularis.

    Abdominal Region

    • Reaching over your head also requires some work from your abdominal muscles to stabilize your body, which prevents you from losing your balance. When you reach overhead from a standing position, you will your abdominal muscles -- internal and external obliques and rectus abdominis -- contract. Based on the myofascial meridian lines described by Myers, your abdominal muscles are attached to your latissimus dorsi, which is a broad back muscle that extends from the back of your pelvis and lower back to your upper arm near your shoulder joints. If these muscles don't keep your torso and spine in place properly, you won't be able to reach up very high.