Upper back (Thoracic spine)
Limited rotation in the backswing, a feeling of "lifting" the arms instead of turning, or tightness between the shoulder blades after playing.
An evaluation looks at Thoracic rotation in both directions, rib cage excursion, and shoulder-blade glide.
Shoulders
Short backswing, inability to get the hands high without arching the back, or shoulder aching on the lead arm.
An evaluation looks at Glenohumeral internal/external rotation, horizontal adduction across the chest, and rotator cuff stability.
Hips & pelvis
Swaying off the ball, sliding forward on the downswing, or pinching in the front of the hip when turning through.
An evaluation looks at Hip internal/external rotation on both sides, hip extension, and pelvic tilt control.
Lower back (Lumbar spine)
Stiffness or aching during or after a round, especially after eighteen holes or range sessions with drivers.
An evaluation looks at Lumbar spine segmental motion, core endurance, and whether restrictions in the hips or upper back are forcing the lower back to twist.
Balance & feet
Falling backward on the follow-through, inability to post up on the lead leg, or ankle stiffness on uneven lies.
An evaluation looks at Ankle dorsiflexion, subtalar joint mobility, and single-leg balance with eyes open and closed.