The Back… Upper and Lower

Upper Back:  The main muscles of the upper back are the latissimus dorsi, teres major and the rhomboids.  The muscles dominate the middle and outside (lateral) parts of the back, and when well-developed, they give a triangular appearance to the torso.  The “lats” are powerful shoulder extensors, so they are well developed in swimmers and rowers.  Other sports which require strong upper back muscles are gymnastics, golf, racket sports and cross country skiing.

The rhomboids lie between the shoulder blades (scapulae) and the vertebral column.  Their main function is to pull back (retract) the scapulae and they also assist in forcibly lowering the arms from a raised position.  Consequently, the rhomboids are used in activities in which the lats are involved.  The rhomboids also play an important role in maintaining correct posture, as they keep the shoulders from drooping forward and becoming rounded.

Lower Back:  The muscles of the lower back act to maintain an erect posture by stabilizing the posterior trunk.  There are numerous muscles involved in this function, which are together called the erector spinae group.  Their main purpose is to extend the spinal column, and they also stabilize the spine during forced expiration (coughing or sneezing).  The erector spinae muscles lie beneath the latissimus dorsi muscle on either side of the spine.  Trunk extension, or straightening of the back, is the most powerful movement of the trunk and, therefore, is extremely important in athletics and activities of daily living.

Weakness of the lower back muscles may result in an inability to maintain an upright posture which allows the shoulders and upper back to droop forward.  If the weakness is severe enough, the lower back will lose its support and become unstable.  This increases the likelihood of injury and pain, not only to the spine, but also to the ankle, knee and hip joints.

Injuries to the back are commonly caused by extremes in range of motion, such as hyperextension, hyperflexion and severe rotation of the spine.  Instability of the lower back causes a greater demand on the abdominal muscles because of a forward shift of the trunk posture and weight. This change in weight distribution disrupts postural balance and adversely affects the correct biomechanics of the body.

In order to avoid injuries to the muscles of the lower back, it is extremely important to warm up before any physical activity.  Great care must be taken to ensure that correct form is used during all weight lifting techniques, since dthe lower back muscles are active to some degree in nearly every single lifting exercise and can therefore be injured.  Extra care musdt be taken when performing exercises which work the lower back muscles directly.

For more information on back exercises, see your favorite Hamilton Personal Trainer today!!!