Table 1.

Summary of tests included in the reproducibility and test-retest study

Test	Subject position and task	Equipment	Outcome	Reference
CCFT	Supine crook lying position, cervical spine in neutral. Pressure Biofeedback placed suboccipitally and inflated to 20 mmHg. Subject performs cranio-cervical flexion through five progressive stages (22-30 mmHg)	Pressure Biofeedback (Stabilizer Chattanooga Group, South Pacific)	20,22,24, 26,28,30 mmHg.	[38]
DCE	Prone, legs straight, arms by the side. Laser light attached to the head, aimed at a target on the floor (60 cm distant). Subject performs low cervical extension with the cranio-cervical region maintained in a neutral position (light on target).	Laser Light, Head Band, Target sheet	Seconds (0-120)	[48]
ROM	Sitting, feet supported. Bubble inclinometer placed on the highest point of the head. Active flexion, extension and lateral flexion are performed. Rotation is performed with the designated equipment (Figure 2).	Bubble inclinometer (Baseline Bubble Inclinometer, Fabrication Enterprises Inc, USA)	Degrees (0-100)	[65]
JPE	Sitting, feet supported. Wearing a cap with a centimetre measure attached to the back (horizontal and vertical). Laser light placed behind, with starting position at 0. Active neck rotation, flexion, extension are performed with eyes closed and reposition error is measured.	Laser light, cap with millimetre measure	Millimetre (0-50)	[23]
GS	Sitting, feet supported. Black marker on a wall positioned 1 m in front. Subject keeps gaze fixed on the marker while performing active neck rotation, flexion and extension.	Marker	Positive/Negative based on patients report of symptoms such as nausea, dizziness, disturbed vision.	[12, 13]
SPNT	Sitting, feet supported. Head in neutral position. Subject follows with eyes, a pen moving horizontally from side to side ~30 cm in front whilst keeping head still. Task repeated with the neck in torsion position	Marker, Pen	Positive/Negative based on patients report of symptoms such as nausea, dizziness, disturbed vision.	[57]
SWAY	1) Standing, feet together. Arms crossed over chest. Keep focus on a black marker positioned 2.5 m in front, stand as still as possible (eyes open and closed). 2) Standing on the non-dominant leg. Arms crossed over chest. Keep focus on a black marker 2.5 m in front, stand as still as possible.	Wii balance board (Nintendo, Kyoto, Japan), SwayWithWii software program	95% Confidence Ellipse Area	[63]
			Anterior/Posterior sway (cm.)
			Medio/Lateral sway (cm.)
			Centre of Pressure Path Length (cm.)
PPT	Supine for PPT over tibialis anterior. Prone for PPT over the infraspinatus and over the cervical column, between the transverse processes of C3 and C4. Pressure applied at a slow rate.	Hand-held algometer (Wagner, FPX algometer, USA)	Kgf	[28]

Tests included were Cranio-Cervical Flexion Test (CCFT), Deep Cervical Extensor test (DCE), Range of Movement (ROM), Joint Position Error (JPE), Gaze Stability (GS), Smooth Pursuit Neck Torsion Test (SPNTT), Balance/Postural Control (SWAY) and Pressure Pain Threshold (PPT).

The pictures were produced for the purposes of this study. The subjects appearing in the pictures have provided consent to publish.