Questions and Answers

To physiotherapy colleagues, if you have a question or problem that you would like us to consider, please email us

Pregnancy and AS

This question came from a committee member regarding a patient with AS, who is in her first pregnancy and has been told by her obstetrics team that she would most likely to to need a C-section due to sacroiliac fusion She also has hypermobility with a reported Beighton's Score of 9/9.

There is very little evidence or national guidelines to support a definitive answer here.

We must firstly emphasise that all decisions regarding delivery must be made on an individual basis. As a mother with AS would be considered a high risk on the basis of her spinal symptoms, referral to an obstetrician is advised. Parents should take advice from the whole team and carry out their own research. Ensure regular monitoring and expect decisions to change dependant on circumstances.

  • As in all pregnancies the size of the mother, baby and position is always a consideration.
  • An AS patient with fusion of SIJ would be considered high risk and on balance a c-section may be the safest option for mother and baby.
  • The presence of pelvic girdle pain is always a consideration, however pain free hip abduction is not considered a predictor for delivery type.
  • A fused sacrum will increase strain on the syphasis pubis which could lead to problems both anti-natally and post-natally.
  • It is generally felt that having AS does not automatically mean an elective c-section, however risk and co-morbidities may lead to the need.
  • Planning for pain medication and the feasability of epidural anaesthesia must also be taken into consideration.
  • If vaginal delivery is the desired option plans around potential birthing positions (4 point kneeling/side lying birthing pool) should be discussed and carefully documented. Also birth wishes should she fail to progress e.g. an earlier stage c-section?
  • All concerned should be fully aware and avoid uncontrolled pelvic/hip movement (crook lying legs suspended in stirrups whilst anaesthetised).
  • The physiotherapist can be a valuable asset at this time by providing appropriate anti and post natal exercise, monitoring progression, comfortable range of axial and peripheral movements and inform decisions.
  • Hypermobility may not have a relevance in decision making.
  • Advice, guidance and support may be necessary post child birth in either scenario and the parents should be made fully aware of possible restrictions in function.

Lung Function

Dear AStretch,

I have a patient who has recently been diagnosed with AS. His chest expansion is pretty poor and he complains of tightness across the chest, in-keeping with AS symptoms. I have performed basic lung function testing this afternoon using a spirometer and the results were expectedly low. I was wondering if:

  1. You had any normative values for lung function of an AS patient/knew where I could find them? I’ve been looking through the literature but of the ones I have read so far I couldn’t see anything conclusive.
  2. If you had any thoughts around inspiratory muscle training devices?

Many thanks for your most interesting question which has certainly stimulated quite a discussion amongst the AStretch committee, but unfortunately none of us knew of documentation that gave normative values for lung function of an AS patient.
I have attached 10 references, that you may have already read, but if not they may be of some use and interest related to chest expansion and pulmonary function in AS patients.
As far as inspiratory muscle training devices, all of the committee agreed that they would have to ask their Respiratory team colleagues as it is not normally something they use themselves.

Included here are some of the committee’s comments around general respiratory training for AS patients that they find useful:

  • The Modified New York Criteria has chest expansion as a component - it is measured against normal range for sex and age (which you can find online).
  • Re inspiratory training, I would liaise with the respiratory team but doesn't immersion (hydro) provide some resistance and therefore training effect which can be varied according to the depth of immersion? Obviously their ability to cope with this will depend upon how poor their current level is. The other benefits of hydro may also then be helpful for his other AS chest symptoms (assuming that all cardiac possibilities have been excluded).
  • I find that using a theraband is a good resistance and muscle training device for the inspiratory muscles.
  • Outcome measures: Chest expansion (5-8 cms), lung function test using spirometry and Incentive spirometry readings matched against age, sex and height - being largest at around 20-25 years The general lung function test normative values can be found from google search including :
  • Therapy plan: Deep breathing with inspiratory end hold techniques, work with incentive spirometer, exercises with towel assistance, theraband resisted pectoral stretches/ upper & mid trunk flexor stretches, rib springing manual techniques in crook lying position. Aerobic based exercise such as swimming, running, cycling will all help increase your lung volume /function.

Sorry that we have been unable to answer your question directly.

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