APPENDIX 4.

Sensitivity when including mixed damage in the isolated PFJ damage group and specificity if mixed damage included in the none/isolated PFJ damage group.

		Sensitivity (Including Mixed)	Specificity (Including Mixed)
AKP	Any	55	50
	Isolated	22	82
Max pain with stairs (up or down)	(≥ min)	79	24
	(≥ mod)	38	65
Pain going up stairs	(≥ min)	74	28
	(≥ mod)	33	70
Pain going down stairs	(≥ min)	71	31
	(≥ mod)	31	74
Absence of pain walking on level ground	(≥ min)	56	45
	(≥ mod)	90	13
Any AKP + max pain with stairs	(≥ min)	48	58
	(≥ mod)	24	81
Any AKP + absence of pain walking on level ground	(≥ min)	29	73
	(≥ mod)	49	57
Isolated AKP + max pain with stairs	(≥ min)	17	86
	(≥ mod)	6	97
Isolated AKP + absence of pain walking on level ground	(≥ min)	16	86
	(≥ mod)	20	83

AKP: anterior knee pain; max: maximum; min: minimal; mod: moderate.