ExRx.net > Kinesiology > Deficiencies

Translate

Standing Postural Muscles The diagram to the right illustrates how the body is held erect. The thick black lines represent the principal muscles involved in standing. The vertical dotted line indicates the center of gravity. Note this line falls behind the axis of rotation of the hip and in front of the knee. This renders the ligaments of the joints tense, which are represented by dotted lines passing in front of the hip (ilio-femoral) and behind the knee (posterior ligament). Posterior Pelvic Tilt Sometimes referred to as flat back, posterior pelvic tilt involves the reduction of the natural lumbar curvature. This posture is characterized by the shortening of the hip extensors (Hamstrings & Gluteus Maximus inflexibility), tight abdominals, and lax hip flexors. Sitting on the back of the hips may indicate a posterior pelvic tilt. It is rarely brought about by lack of muscular strength. The posterior pelvic tilt is less common as the anterior tilt as seen with lordosis. Examples of affected exercises: Leg Press Squat Straight Leg Deadlift Example preventative / corrective exercises: Hip Flexor: Lever Hip Flexion Hamstrings: Lying Hamstring Stretch Gluteus: Seated Glute Stretch Abdominal: Abdominal Stretch Lordosis Pelvis is positioned forward and downward. Hips are slightly flexed and lumbar spine is excessively hyperextended. Hip flexors, erector spinae are short. Abdominal, hamstrings, gluteus maximus muscles may be weak. Increased risk of lower back injury during standing or lying hip extension, flexion, or stabilization activities, and weighted overhead activities. See abdominal weakness and hip flexor inflexibility. Examples of affected exercises: Squat Hack Squat Military Press (standing) Roman Chair Sit-up Example preventative / corrective exercises: Hip Flexor: Kneeling Hip Flexor Stretch Erector Spinae: Lower Back Stretch Abdominal: Crunches Hamstrings: Leg Curl Gluteus: Seated Leg Press Kyphosis Exaggerated anterior-posterior curvature of the vertebral column, most often involves an excessive forward bending in the thoracic area. Kyphosis occurs in older adults, particularly women with osteoporosis and osteoarthritis. Kyphosis is sometime accompanied with other posterior problems such as posterior or anterior pelvic tilt (compensates for altered line of gravity) and protracted shoulder girdle (unrelated). Kyphosis makes it difficult to include overhead exercises particularly when combined with a winged scapula condition or shoulder external rotation inflexibility. Examples of affected exercises: Shoulder Press Seated Triceps Extension Front Squat Overhead Squat Corrective exercises for gravity induced kyphosis: Strengthening of thoracic vertebral column extensors Stretching of thoracic vertebral column flexors Forward Head Posture An anterior positioning of the cervical spine is characteristic of forward head posture, or protracted neck. Forward head posture may make it more difficult to perform exercises with the bar in front of head or neck. Evaluate neck position at night since elevating head too high with additional pillows may act as a continuous neck stretch throughout the evening exacerbating the forward head posture. Examples of affected exercises: Shoulder Press Corrective exercises for gravity induced kyphosis: Strengthening of cervical vertebral column extensors Isometric Neck Retraction Stretching of cervical vertebral column flexors Neck Retraction

Winged Scapula Medial border or inferior angle of scapula protrudes slightly from body. A winged scapula condition may be accompanied by a protracted shoulder girdle. Risk of shoulder injury is compounded with a supraspinatus weakness or an external shoulder rotation inflexibility. Because of the forward tilt of the scapula, complete flexion or external rotation of the shoulder may be seemingly restricted. A winged scapula condition indicates a serratus anterior weakness. The rhomboids may be weak and the pectoralis minor may be short. A winged scapula is considered normal posture in young children, but not older children and adults. Examples of affected exercises: Shoulder Press Pullovers Pull-downs Example preventative / corrective exercises: Incline Shoulder Raise Cable Row Pectoralis Minor Stretch Wall Lat. Stretch Protracted Shoulder Girdle The shoulders are pulled forward. Medial border of the scapula may also protrude slightly from body. Increased risk of shoulder injury during shoulder transverse flexion and transverse adduction activities, specifically when elbow travels behind shoulder. Scapula protraction can also decrease width of subacromical space, possibly increasing risk of subacromical impingement (Solem-Bertift E, et al. 1993). In both cases, risk of shoulder injury is compounded with a infraspinatus weakness. Possible limited range of motion during retraction of the shoulder girdle. A protracted shoulder girdle may be accompanied by a winged scapula condition or transverse adduction / flexion inflexibility. The subscapularis and Pectoralis minor and clavicular & sternal heads of the pectoralis major muscles may be short. The trapezius (middle fibers) and particularly the rhomboids may be weak if the medial borders of the scapula also protrude slightly from body. Examples of affected exercises: Bench Press Chest Press Flies Barbell Hack Squat Upright Row (particularly close grip) Front Lateral Raise (with internal shoulder rotation) Example preventative / corrective exercises: Cable Row or Lever Row (do not hold protracted position) Doorway Modified Chest Stretch Wall Shoulder Girdle Stretch Doorway Subscapularis Stretch Work through full range of motion on chest exercises just to position that slight stretch is felt. If lying on one's side, position upper arm under head (with or without pillow in between) since lying on one's side with one's arm down or in front (protracting shoulder girdle) may act as a continuous stretch throughout the night exacerbating this condition. Likewise, those with a protracted shoulder girdle should avoid stretches that protract the shoulder such as Rear Delt Stretches or holding a protracted position during rowing resistive exercises. Normalizing this postural deficiency can improve mechanics of the shoulder and provide a fuller appearance throughout the chest. Scoliosis Mediatorial curve of the vertebral column.