Final answer:
In the case of lordosis, the hip flexors are commonly tight, while the deep core muscles are usually lengthened. In the case of kyphosis, the chest muscles are commonly tight, while the muscles of the upper back are usually lengthened. In the case of swayback and flat back, the lower back muscles are commonly tight, while the hip flexors and hip extensors are usually lengthened.
Step-by-step explanation:
In the case of lordosis, the muscles that are commonly tight are the hip flexors, such as the iliopsoas and rectus femoris. These muscles are responsible for the excessive anterior curvature of the lumbar region. The muscles that are usually lengthened are the deep core muscles, such as the abdominal wall muscles, which can become weakened and stretched due to the excessive anterior tilt of the pelvis.
In the case of kyphosis, the muscles that are commonly tight are the chest muscles, such as the pectoralis major and pectoralis minor. These muscles contribute to the excessive posterior curvature of the thoracic region. The muscles that are usually lengthened are the muscles of the upper back, such as the rhomboids and trapezius, which can become weakened and lengthened due to the rounding of the shoulders.
In the case of swayback, the muscles that are commonly tight are the lower back muscles, such as the erector spinae, which contribute to the excessive anterior tilt of the pelvis. The muscles that are usually lengthened are the hip flexors, similar to the case of lordosis.
In the case of flat back, the muscles that are commonly tight are the lower back muscles, similar to the case of swayback. The muscles that are usually lengthened are the hip extensors, such as the gluteus maximus and hamstrings, which can become weakened and lengthened due to the lack of natural curvature in the lower back.