Final answer:
An exaggerated thoracic kyphotic posture can lead to an anterior pelvic tilt as a compensatory motion.
Step-by-step explanation:
In a patient with exaggerated thoracic kyphotic posture, a possible compensatory motion that would be seen is anterior pelvic tilt (option b).
Kyphosis, or hunchback, is an excessive posterior curvature of the thoracic region. This can develop when osteoporosis causes weakening and erosion of the anterior portions of the upper thoracic vertebrae, resulting in their gradual collapse. In order to maintain balance, the body compensates by tilting the pelvis forward, leading to an anterior pelvic tilt. This helps to align the center of gravity and prevent falling forward.
Therefore, in a patient with genu recurvatum and an exaggerated thoracic kyphotic posture, an anterior pelvic tilt would be a possible compensatory motion.