The middle and lower trapezius, rhomboids, rotator cuff are underactive in which region?

• A. Underactive LPHC muscles
• B. Underactive shoulder muscles
• C. Underactive knee muscles
• D. Underactive feet muscles

Answer: (A)

A stable lumbo-pelvic-hip complex (LPHC) provides the foundation for coordinated upper-body movement. The middle and lower trapezius, rhomboids, and rotator cuff act as shoulder-stabilizing muscles that rely on a solid core to fire and work effectively. When the LPHC is underactive, the trunk can’t supply a stable base or transfer force efficiently to the upper body, so these shoulder-stabilizing muscles don’t engage optimally and may appear underactive in this region. Training that improves core and hip stability helps these shoulder muscles recruit correctly, improving posture and shoulder function. The other regions don’t capture this important link between core stability and scapular/rotator cuff function.