Low Back Pain: How to Spot a Flexion Rapid Responder | Modern Manual Therapy Blog

Low Back Pain: How to Spot a Flexion Rapid Responder


MDT is often not portrayed correctly and many students and clinicians often report rows of tables in their clinic with everyone doing prone press ups or some form of extension.


What is true is that a majority of lumbar rapid responders have the directional preference of extension for

  • symmetrical low back pain
  • central low back pain
  • unilateral low back pain with or without radiation (most likely to above the knee) if sidegliding in standing is also symmetrical
At the time when I got certified in MDT in 2004, a few instructors had said McKenzie himself had not seen a flexion rapid responder (or anterior derangement in MDT terms). This is rare because most people flex thousands of times a day and lose the ability to extend or load their spines. Independent of mechanism (disc, perceived threat to load, etc), this is a common pattern.

The typical lumbar extension rapid responder has
  • extension based directional preference
  • pain in flexion, but flexion may be FP
  • extension may be DN, or DP, rarely FP
  • repeated loading into extension rapidly increases extension and centralizes and abolishes perceptions of low back pain
  • repeated loading into flexion, causes rapid loss of extension - important if done too much/too early
Reverse this for the flexion rapid responder
  • flexion based directional preference
  • pain in flexion or mod to major loss, DP or DN
  • extension is most likely FP
  • no pain below the knee, Sx normally symmetrical or central
  • repeated flexion causes rapid improvement in LBP and flexion ROM
  • important! repeated loading into extension causes rapid loss of flexion
The last point is the most important part and why it's rarely seen. I often tell patients, if flexion/slouching was going to improve your complaints, it would've done it by now. Of the 4 cases of flexion rapid responder I have seen in the past 16 years, 3 have been my wife right shortly after she's had a child. She's a pro at doing repeated extensions throughout the day prophylactically. However, after being in anterior pelvic tilt with a larger belly for several months, she often gets right back to repeated extension in lying after giving birth. Each time, this did not abate her low back ache. In each case, repeated extension caused a loss of flexion. A combination of flexion in lying (repeated knees to chest) and flexion in standing/sitting rapidly improved her flexion and abolished LBP. A quick test after 15-20 flexions of 10 extensions caused rapid loss of flexion. After 2-3 days of repeated flexion, all symptoms were abolished. and she learned to balance flexion and extension.

MOST people will not be flexion rapid responders due to all the flexion unloading they perform most of the day. It's either hyperextension injuries (the only other case I've seen in 16 years) or overly compliant patients with rigid posture that may be a flexion rapid responder. Any questions - comment below or email me!

Keeping it Eclectic...

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