Complete twin pairs (pairs = 4418) | Twin II | Singleton twins (n = 7271) | |||
No LBP or NSP | Solely LBP | Solely NSP | Concurrent LBP and NSP | ||
Twin I | |||||
No LBP or NSP | 1773 | 291 | 420 | 208 | 4515 |
Solely LBP | 277 | 75 | 67 | 55 | 759 |
Solely NSP | 425 | 80 | 165 | 110 | 1156 |
Concurrent LBP and NSP | 223 | 56 | 113 | 80 | 841 |
LBP, low back pain; NSP, neck–shoulder pain.