2D (meta, ankle, knee, hip) (how to define the CF-files).
	KO (one or two legs)
	KM (one or two legs)
	HH (one or two legs)
	Anthropometric measures and table values for 2D, KO, KM and HH
	Templates for missing markers with 4, 5 and 6 cameras.

	Easy to track automatically  -  Should minimize the chance of hiding or merging of the markers
	At least three noncolinear markers on a body segment - At least three markers are attached on a body segment - Can be reduced to 2 markers if we use virtual markers, such as joint center - for example,  Helen Hayes marker set uses 13 or 15 markers for 7 body segments.
	Able to define anatomically relevant LCS - To estimate joint centers accurately and to define anatomical planes (sagittal or coronal) of body segments should be warranted.

* Comparison Table 

	HHo	HHm	KVo	KVm	Sun
No. of markers	15 (17 for static)	15 (with two heels)	15	15	19 (23 for static)
Use of wand	o	o	x	o	x
Hip joint center estim.	Davis algorithm	Davis algorithm	based on stero x rays	based on stero x rays	Bell's algorithm
Knee joint center estim.	from thigh wand(marker) and knee width	from thigh wand and knee width	based on stero x rays	from tibia wand and knee width	midpoint btwn med. and lat. epicondyle
Ankle joint center estim.	from tibia wand and knee width	from tibia wand and knee width	based on stero x rays	based on stero x rays	midpoint btwn med. and lat. malleolus
Potential problems	1. No heel markers-cannot calculate Euler angles (but for Dalmatian projec, heel markers are used for HHo) 2. Difficulty to digitize G. trochant marker 3. Swaying wand markers esp. during jerky gait 4. Possible inaccurate hip joint center estim	1. Swaying wand markers esp. during jerky gait 2. Possible inaccurate hip joint center estim 3. Because there is no G troch. marker, "2" can introduce error on knee joint center estim.	1. Somewhat difficult to digitize automatically 2. Possible inaccurate hip, knee and ankle joint center estim, because of small sized sample for the stereo x rays.	1. The hip joint center estim. is same as KVo. 2. Use tibia markers to estimate knee joint center. 3. Swaying wand markers esp. during jerky gait	1. Soft tissue movement beneath the thigh ant. marker

* No algorithm of hip joint center estimation seems to be absolutely accurate. - more about hip joint center estimation

　

Marker Name	HHo	HHm	KVo	KVm	Sun
SACR	O	O	O	O	O
R,L ASIS	O	O	O	O	O
R,L GTRO	O	-	O	-	-
R,L THI_W	O	O	-	O	-
R,L THI_L	-	-	-	-	O
R,L THI_A	-	-	-	-	O
R,L LCON	O	O	O	O	O
R,L MCON	-	-	-	-	D (for static)
R,L TIB_W	O	O	-	O	-
R,L TTUB	-	-	O	-	O
R,L FH	-	-	-	-	O
R,L LMAL	O	O	O	O	O
R,L MMAL	-	-	-	-	D (for static)
R,L MT	D (5th MT)	O	D (5th MT)	O	O
R,L HEEL	O (-)*	O	O	O	O
Totoal No	15	15	15	15	19 (21 static)

　*: In original HHo, there was no heel marker. But for this study we included heel markers for HHo marker set. We are not to compare the ankle angle with or without heel markers because it is obvious that former is better than later.

Marker Name	Full Name	Detailed Instructions
SACR	Sacrum	keep the center of marker to be on the reversed direction of �i� vector of pelvis LCS
R,L ASIS	Ant. Sup. Iliac spine	keep the center of marker to be on the direction of �i� vector of pelvis LCS
R,L GTRO	Greater Trochanter	On the greater trochanter of femur
R,L THI_W	Thigh wand	a stick marker on the lower lateral thigh. Should be on the plane that is formed by hip join, knee joint and lateral epicondyle marker.
R,L THI_L	Thigh lateral	on the lateral thigh. The plane formed by RTHI_A, hip joint center and knee joint center will be sagittal plane of thigh.
R,L THI_A	Thigh anterior	on the anterior thigh. Should be on the plane that is formed by hip join, knee joint and lateral epicondyle marker.
R,L LCON	Lateral Epicondyle	on the center of lateral epicondyle of femur. You can find it more easily if the subject�s knee flexed a little.
R,L MCON	Medial Epicondyle	only for static trial. on the center of medial epicondyle of femur. You can find it more easily if the subject�s knee flexed a little.
R,L TIB_W	Tibial wand	a stick marker on the upper lateral surface of lower leg. Around upper 1/3 point of fibular head to lateral malleolus, where is no tibial torsion component.
R,L TTUB	Tibial tuberosity	On the tibial tuberosity
R,L FH	Fibular Head	On the fibular head. But 2 or 3cm inferior to fibular head would be better to avoid merging with lateral condyle marker
R,L LMAL	Lateral Malleolus	Center of lateral malleolus
R,L MMAL	Medial Malleolus	Center of medial malleolus
R,L MT	Head of 2nd Metatarsal	on the second MT head
R,L HEEL	Heel	On heel. The line between RHEEL and RMT should be parallel to the ground. To achieve this condition: one should measure the thickness(height) of 2nd MT head(=RMTHth). The RHEEL should be above from the ground with the amount of m_offset1+RMTHth.