Skeletal Muscle by ischinca October 4, 2020 A condensed summary of the superficial muscles of the body. A muscle strain is a tear in the muscle fibers leading to loss of the muscle’s ability to contract. The muscles labeled above are most likely to tear when excessive force is applied. Sitting all day and looking at screens commonly leads to some or all of the postural imbalances noted above (forward tilting pelvis, rounded shoulders, forward head position). In this posture, some muscles are overused and tight while other muscles (pictured above) are weak and underused. Share FacebookTwitterPinterestEmail