Original Editor - Jason Cirolia
Brian R. Mulligan qualified as a physiotherapist in 1954 and gained his diploma in Manipulative Therapy in 1974. He has been the author of numerous articles published in New Zealand Journal of Physiotherapy. He is also the author of two books:
- "Manual Therapy "NAGS","SNAGS", "MWMS",etc' (2003) for Physiotherapists.
- 'Self Treatment for the Back, Neck and Limbs' for Public.
- NAGS- Natural Apophyseal Glides.
- SNAGS - Sustained Natural Apophyseal Glides.
- MWMS- Mobilization with Movements.
- The concept of Mobilizations with movement (MWM) of the extremities and SNAGS (sustained natural apophyseal glides) of the spine were first coined by Brian R. Mulligan 
Mobilization with movement (MWM) is the concurrent application of sustained accessory mobilization applied by a therapist and an active physiological movement to end range applied by the patient. Passive end-of-range overpressure, or stretching, is then delivered without pain as a barrier.
Concept of Positional Fault
- Mulligan proposed that injuries or sprains might result in a minor "positional fault" to a joint causing restrictions in physiological movement.
- The techniques have been developed to overcome joint `tracking' problems or `positional faults', i.e. joints with subtle biomechanical changes.
- Normal joints have been designed in such a way that the shape of the articular surfaces, the thickness of the cartilage, the orientation of the fibres of ligaments and capsule, the direction of pull of muscles and tendons, facilitate free but controlled movement while simultaneously minimizing the compressive forces generated by that movement 
- Normal proprioceptive feedback maintains this balance. Alteration in any or all of the above factors would alter the joint position or tracking during movement and would provoke symptoms of pain, stiffness or weakness in the patient. It is common sense then that a therapist would attempt to re-align the joint surfaces in the least provocative way
Principles of Treatment
- A passive accessory joint mobilization is applied following the principles of Kaltenborn. This accessory glide must itself be pain free.
- During assessment the therapist will identify one or more comparable signs as described by Maitland. These signs may be; a loss of joint movement, pain associated with movement, or pain associated with specific functional activities
- The therapist must continuously monitor the patients reaction to ensure no pain is recreated. The therapist investigates various combinations of parallel or perpendicular glides to find the correct treatment plane and grade of accessory movement.
- While sustaining the accessory glide, the patient is requested to perform the comparable sign. The comparable sign should now be significantly improved
- Failure to improve the comparable sign would indicate that the therapist has not found the correct treatment plane, grade of mobilization, spinal segment or that the technique is not indicated.
- The previously restricted and/or painful motion or activity is repeated by the patient while the therapist continues to maintain the appropriate accessory glide.
While applying "MWMS" as an assessment, the therapist should look for PILL response to use the same as a Treatment .
- P- Pain free.
- I- Instant result.
- LL- Long Lasting.
If there is No PILL response, that technique should not be advocated. The second principle is CROCKS
- C- Contra-indications (No PILL response is a contraindication)
- R - Repetitions (Only three reps on the day one)
- O- Over pressure
- C- Communications
- K - Knowledge (of treatment planes and pathologies)
- S- Sustain the mobilization throughout the movement.
- SNAGs stand for Sustained Natural Apophyseal Glides.
- SNAGs can be applied to all the spinal joints, the rib cage and the sacroiliac joint.
- The therapist applies the appropriate accessory zygapophyseal glide while the patient performs the symptomatic movement.
- This must result in full range pain free movement.
- SNAGs are most successful when symptoms are provoked by a movement and are not multilevel.
- They are not the choice in conditions that are highly irritable.
- Although SNAGs are usually performed in weight bearing positions they can be adapted for use in non weight bearing positions.
If a patient is suffering from a headache of upper cervical origin then one of the mobilisations or the traction to be described should, as it is being applied, stop the pain. Mulligan assumes that if a headache stops with a manual technique involving the upper cervical spine then, this must be diagnostically significant as to the site of the lesion causing the problem and the fact that there is a mechanical component.
- Position of Patient: sitting
- Position of therapist: stands beside the patient, while his\her head is cradled between your body and your right forearm (when you stand at his\her right side)
- Start by placing your right index, middle and ring fingers at the base of the occiput. The middle phalanx of the same hand and the little finger lie over the spinous process of C2. Then place the lateral border of the left thenar eminence on top of your right little finger.
- Gentle pressure is now applied in a ventral direction on the spinous process of C2 while the skull remains still due to the control of your right forearm. (The really gentle moving force to do this comes from your left arm via the thenar eminence over the little finger on the spine of C2).
- The pressure applied by the index finger moves the lower vertebra forward under the first until the slack is taken up, then the first vertebra moves forward under the base of the skull. This is quickly taken forward until end range is felt and this position is maintained for at least 10 seconds. If indicated the headache will relieve, repeat the HEADACHE SNAG six to ten times. Some patients have a more favourable response when the position is sustained for a much longer time- up to a minute.
Important, when applying the “ Headache SNAG” the good manual therapist will imperceptibly alter the direction of the glide to effect a change. Small adjustments in direction may be necessary as the true facet plane directions vary between individuals.
- NAGs stand for 'Natural Apophyseal Glides”.
- NAGs are used for the cervical and upper thoracic spine.
- They consist of oscillatory mobilizations instead of sustained glide like SNAGs, and it can be applied to the facet joints between 2nd cervical and 3rd thoracic vertebrae.
- NAGs are mid-range to end range facet joint mobilizations applied antero-superiorly along the treatment planes of the joint selected.
- Useful for grossly restricted spinal movement.
- NAGs for the treatment of choice in highly irritable conditions
Peripheral MWM 
- Once the aggravating movement has been identified, an appropriate glide is chosen.
- The decision to use weight-bearing or Non-weight bearing movement depends upon the severity, irritability and nature of the condition.
- Once the glide has been chosen it must be sustained throughout the physiological movement until the joint returns to its original starting position
- Mobilizations performed are always into resistance but without pain
- Immediate relief of pain and improvement in ROM are expected.
- If this is not achieved, vary the glide parameters
Spinal Mobilization with Limb Movement (SMWLMs) 
- Here a transverse pressure is applied to the side of the relevant spinous process as the patient concurrently moves the limb through the previously restricted range of movement.
- The assumption here is that the restriction of movement is of spinal origin of course.
- This does not necessarily imply neural compromise since spinal movement must occur when a limb moves beyond a certain point.
- Thus the technique addresses a spinal structural/ mechanical restriction, but this may have neural implications too.
- Manual therapy NAGS,SNAGS,MWMS,etc by Brian R.Mulligan, 5th edition, 2004.
- Mulligan, BR: Manual Therapy “NAGS,” “SNAGS,” “MWM’S: Etc., ed 4. Plane View Press, Wellington, 1999
- Kisner, Carolyn, and Lynn Allen Colby. Therapeutic exercise: foundations and techniques. FA Davis, 2012.
- Wilson, Ed. "The Mulligan concept: NAGS, SNAGS and mobilizations with movement." Journal of bodywork and movement therapies 5.2 (2001): 81-89.
- Manual therapy NAGS,SNAGS,MWMS,etc by Brian R.Mulligan, 6th edition, 2010.
- Brain R Mulliga,2010, manual therapy NAGS,SNAGS,MWMS etc,sixth edition,Wellington 6241,New Zealand
- Exelby, Linda. "Peripheral mobilizations with movement." Manual Therapy 1.3 (1996): 118-126.