Phil Patton

Noted above is a lack of maintaining even weight-bearing through both legs – was there a shift of her center of mass over her base of support that isn’t noted here?

Yes, her COM shifted to the right of BOS early in the squat. I realise now that I only reported this as an increase in the left TPR with the squat.

Did the COM change over her BOS when the TR3 & 4 were corrected?

Yes, the COM over BOS improved with correction of TR3 and 4 (but not fully).

If full correction of the pelvis and hip was not achieved with the correction of the thorax, they are still considered as secondary drivers at this point.

I like your point here: drivers are considered secondary until we can prove they are the best correction.

But it may have changed in the squat task – sometimes impairments in a movement task are not present in neutral standing, or the starting position and only show up as the task progresses, especially if the dura cannot permit elongation in the task, the cranium will often twist or rotate in this situation, so should be screened – make sense?

Yes, that makes sense.

If the noted L translation/R rotation of C7 increased in the squat and TR2 position didn’t change, something above C7 had to unwind this increase in rotation, which further makes me suspicious of what happened in the craniovertebral region (atlanto-axial joint in particular) and the cranium.

Good point. I’m not sure to be honest. I won’t miss it next time though!

For FU#1 and FU#2 both drivers are translated left/rotated right.  Curious at this point as to where this right rotation will be unwound if not above.

In addition to dorsiflexion at the talocrural joint, which you have noted to be reduced, the hindfoot, midfoot and forefoot should all pronate and the foot should lengthen during a squat.  Can you describe the optimal biomechanics of the 3 regions of the foot during pronation:

1. Osteokinematics and arthrokinematics of the subtalar joints
2. Osteokinematics of the midfoot and forefoot

1. Osteokinematics and arthrokinematics of the subtalar joint in pronation

The subtalar joint is made of up three facets (posterior, middle and anterior) between the talus and calcaneus. Pronation and supination at this joint involves movement primarily in the transverse plane.

Osteokinematics and arthrokinematics of the subtalar joint during pronation are:

• • the talus rotates medially (in space and relative to the anterior part of the calcaneus) in the transverse plane, plantar flexes in the sagittal plane and adducts in the coronal plane relative to the calcaneus.

Terminology of the foot is sososo difficult! I can totally see what you are describing here but it is too broken up into the cardinal planes. In other words the talar movement in all three planes is occurring simultaneously so describing the planes in this way is confusing. When looking from the front of the talus/calcaneus the head of the talus moves osteokinematically ‘down and medial’ with no tilting (coronal plane movement) so we have called this motion plantarflexion/adduction – see picture below.

Pronation of the subtalar joint 

I love this picture! It is much easier to see how the subtalar joint moves in all three planes simultaneously. Awesome.

• • the calcaneus rotates laterally (in space and relative to the talus) in the transverse plane

(in the online course material there are 2 contradictory statements about this movement of the calcaneus. One part says: ‘The posterior calcaneus is fixed on the ground such that lateral rotation of the calcaneus moves the anterior part of the calcaneus laterally’. Another part says: ‘During pronation, the anterior (concave) aspect of the calcaneus glides laterally and the posterior aspect glides medially (posteromedially)’. Which description is best to use?

Good pick up!  The first part is describing the osteokinematics of the calcaneus in space. The posterior part of the bone does not move medially when the heel is on the ground. The axis of motion is through the posterior calcaneus. The next sentence ‘During pronation, the anterior (concave) aspect of the calcaneus glides laterally and the posterior aspect glides medially (posteromedially)’ is describing the arthrokinematics of the two joint complex, in that the anterior concave facet of the calcaneus of the subtalar joint glides laterally (relative to the talus) while the posterior convex facet of the calcaneus of the subtalar joint (that lies in an anterolateral/posteromedial plane) is gliding posteromedially, but the posterior part of the calcaneal BONE is not moving relative to the ground!  Can you see this in your mind now what is being described?

Ah, yes, I can see now I was mixing up osteokinematics and arthrokinematics. I have the visual of the movement in my mind now. Thanks!

• • the calcaneus also plantarflexes in the sagittal plane osteokinematically

2. Osteokinematics of the midfoot and forefoot

The optimal osteokinematics of the mid and forefoot during pronation and supination occur around an axis which goes through the middle cuneiform and 2^nd metatarsal. During pronation, the bones medial to this axis (ie. navicular, medial cuneiform, 1^st metatarsal) rotate externally and the bones lateral to this axis (ie. cuboid, lateral cuneiform and the 3^rd, 4^th and 5^th metatarsals) rotate internally.

Other movements of the mid and forefoot bones that occur during pronation are:

• The medial, middle and lateral cuneiform move plantar in space secondary to the dorsiflexion of the metatarsals.
• The 1^st metatarsal abducts from 2^nd metatarsal and dorsiflexes.
• The 2^nd metatarsal remains neutral with respect to rotation / abduction and dorsiflexes.
• The 3^rd, 4^th and 5^th metatarsals abduct from the 2^nd metatarsal and dorsiflexes.
• The phalanges remain extended and the MTP joints flex slightly.

Perfect!!

You note that the talocrural joint has sub-optimal biomechanics for this squat task, what happened to the rest of the foot from the standing posture to the squat?

As mentioned above, in the standing postural screen, both feet in were in a neutral position. As Miss B squatted, both feet appeared to pronate and lengthen appropriately for the task.

What made you choose a primary/secondary driver in this scenario and not a co-driver? Please include in your answer the definition of each type of driver.

Why did I use primary/secondary driver in this scenario?

I chose C7 as the primary driver because, when it was corrected, it had a large effect on the 3^rd and 4^th TRs, right SIJ, right hip and right knee (almost full correction in all regions). However, when the 3^rd and 4^th TRs were corrected it resulted in only a small amount of improvement in C7, right SIJ, right hip and no change in the right knee or ankle.

Defining different types of drivers
Firstly, it is pertinent to observe the timing of region/s of the body with non-optimal ABCs for a meaningful task (i.e. at what point in the task does each region start to display non-optimal ABCs?). The region/s that display the earliest non-optimal ABCs are frequently the ones driving the non-optimal ABCs in other regions.

I referred to your new 2018 version of The Thorax text book for an up-to-date answer for this question. Primary driver: the region that, when corrected, results in the complete correction of all other regions with non-optimal ABCs for the meaningful task.

Primary driver with secondary driver: correction of one body region results in complete correction of most regions of non-optimal ABCs and an improvement, but not full correction, in another region with non-optimal ABCs for the meaningful task.

Co-driver Type 1: correction of one body region results in worsening of ABCs for another body region for the meaningful task, however, correction of both regions improves the task performance. Co-driver Type 2: correction of one body region results in improvement of ABCs for another body region and correction of the other body region improves the ABCs of the first for the meaningful task.

Of course I would think this was correct! Does it make sense to you?

Yes, the scenario that I’ve described seems to fit into both the ‘Primary driver with secondary driver’ and the ‘Co-driver Type 2’ categories. Though, on deeper reflection, it is probably more the ‘Co-driver Type 2’ because correction of the 3^rd and 4^th TR did improve C7 a small amount in the meaningful task of squatting.

What about the residual loss of control of the right SIJ and alignment of the right hip – did they correct with any correction in FU#2 or 3? They didn’t completely correct with the thorax correction. Although below, you note that the thorax resulted in complete restoration of function of the right SIJ and Hip in the ROLS task.  If true, this is highly suggestive of a foot fault i.e. lack of pronation right foot? That’s the big difference between the squat and OLS task.

Yes, the right SIJ and right hip improved (almost completely) with correction of C7 and their ABCs were completely restored with correction of C7 and the 3^rd and 4^th TR.

When you say ‘at 40% into right OLS task’ do you mean 40% beyond the 50% load sharing position required for standing?  I ask because if she lost control with 40% of her weight being taken through the right leg, then she would be ‘unlocked’ in standing, and she wasn’t – so I’m just trying to gain clarity in your language use of percentages for when things happen in a task.

By 40% I mean almost half between the 50% load sharing position and 100% on the right leg. Therefore, I should say 70% into the right OLS task if two-legged standing is 50%.

Thanks for the clarification.

Same comment as for the squat task. Not sure we can assume that a neutral starting position will be maintained throughout a movement task.

Do you expect there to be any positional change in the hindfoot, midfoot or forefoot when moving from double leg standing to single leg standing?  In other words, in single leg stance should the foot be pronated, neutral or slightly supinated for effective load transfer?

For optimal load transfer in single leg stance, the foot should be slightly supinated compared to double leg standing. This is necessary as the center of mass (COM) has moved laterally over the weight-bearing foot. All the bones and joints of the lower limb need to adjust in order to optimise the load transfer (and avoid excessive compression or shearing forces through the joints or non-optimal forces through the myofascial and neurovascular structures).

I agree, but know of no evidence to validate/confirm our clinical opinion.

Did you observe any limitations or differences in quality of the rotation between sides? Why would seated rotation bring more awareness to this task?

No, there were no perceivable limitations or differences in quality of rotation to the right or left. Seated rotation brings more awareness to the rotation task as the pelvis is now (relatively) fixed and there is no rotation contribution from the lower limb joints. If there are restrictions in any joints between the cranium and the feet, during standing trunk rotation, then many other joints can compensate. However, during seated trunk rotation, there are less joints that can compensate for any restriction. The patient’s awareness is also focused on a smaller region of her body and any differences are easier to perceive.

Why would the trunk be required to rotate to the left during a simple right OLS task? I’m confused here?

Thanks for highlighting this point for me. I used the right OLS as a screening task for running. I now realise that I haven’t been using a simple OLS to observe non-optimal ABCs in regions of the body. I have been using a more complex and integrated OLS by instructing my patients to incorporate their whole body in the movement as if they’re walking or running. This cues them to rotate their pelvis ipsilaterally and thorax contralaterally. I should then describe this screening task as a ‘right OLS with intention to walk or run’.

Or what about ‘right OLS with slight left trunk rotation’? Is highly relevant for her meaningful task.

Yes, that is much a clearer description. Thanks.

In the squat task, you report that the right SIJ lost control at ‘40% into the squat’.  Therefore, it is highly plausible that she was sitting with the right side of her sacrum counter-nutated relative to the right side of her innominate.  Did you check for SIJ control as she sat before testing left seated trunk rotation? Or did you assume that because the pelvis was rotated left in the transverse plane and the innominate was anteriorly rotated on the right and posteriorly rotated on the left that the sacrum would be relatively nutated bilaterally?  Strategies for pelvic control can be impacted by loss of the form closure mechanism when sitting and thoracic ring findings can be pelvic driven in this case.

Yes, as reported above in the squat task assessment, the right SIJ control was lost at 40% into the squat. This was the same for standing to sitting. So, I should correct the statement of ‘Pelvis maintains left IPT’ to ‘There was loss of control of the right SIJ (right side of her sacrum was counter-nutated relative to the right side of her innominate when sitting)’.

It is a common finding when individuals sit with a counternutated sacrum relative to the ipsilateral innominate (unlocked as we call this) to have over-activation of the thoracic longissimus whose aponeurotic distal extension attaches to the dorsum of the sacrum. This attempt to increase the force closure mechanism for pelvic control comes at a cost of thoracic alignment and mobility and thus can indirectly impact your alignment and mobility findings in sitting.  Something to watch for.

Yes, I have found this to be a common in patients who have difficulty relaxing their thoracic longissimus.

This is a very interesting finding and supports my prior suggestion (and current comment about the mechanism of this finding) that she was sitting with loss of control of the right SIJ.

1. Where is the inferior attachment of the fascicle of iliocostalis from the right 4^th rib?
2. If there was over-activation of this fascicle and a deficit in motor control of the pelvis, what would the impact of this over-activation be on the innominate biomechanics relative to the sacrum, and the impact on the right 4^th rib?
3. What would the resultant position be of the 4^th thoracic ring be?

1. The inferior attachment of the fascicle of iliocostalis lumborum from the right 4^th rib is to the medial posterior superior iliac spine (PSIS).
2. If there was over-activation of this fascicle, and a deficit in motor control of the pelvis, it would result in an anterior rotation of the right innominate relative to the sacrum (unlocking of the right SIJ). The right 4^th rib would be posteriorly rotated.
3. The 4^th thoracic ring would be in a left translated / right rotated position.

and it was! Making sense? This doesn’t mean that the pelvis is the driver by any means but helps to understand a potential reason why it was easier to correct the alignment of her thoracic rings in standing vs sitting.

Yes, makes sense. Thanks for highlighting it!

Same comment as before re this omission.

But it might have been relevant for standing trunk rotation in that standing trunk rotation requires more motion of the feet and would be highly relevant for her meaningful task of running.

Phil uses language with this patient we are trying to avoid, that being the term ‘ring shift’. Rings don’t shift but it is a quick and easy thing to say but leaves the patient potentially with the wrong impression.  They translate/rotate and Phil’s body language in these videos is accurate, just his words could be different – he knew that when he submitted this report!

How did you know the pelvis was in an IPT in standing rather than standing with one SIJ unlocked? If you start with unloading one leg and then progressively add weight back to that leg to 50% you would have known if the TPR was associated with an IPT (both sides of the sacrum remain nutated in this instance) or if one SIJ had lost control for the standing position. It appeared that the left SIJ lost control in the squat but it goes very fast in the video I couldn’t see it!

How did you know that correcting his pelvis wouldn’t improve his thoracic ring alignment given what we know about iliocostalis/longissimus and the relationship between the thoracic rings and the pelvis?

I would have liked to see a pelvis correction not change the alignment of the thoracic rings and C7 for final confirmation of a thorax driver.

Yes, unfortunately both of these elements were not demonstrated in the videos, as I had done them in previous sessions with Mr. S. The left SIJ was adequately controlled in standing and correction of the pelvis made the alignment of the upper thoracic rings and C7 worse. Correction of the pelvis also made no change to the left SIJ symptoms when Mr. S was in his bike position.

When you need to use two hands to correct two thoracic rings translated in the opposite direction, it is sometimes difficult to check if pelvic control has been restored.  You can see a change in a TPR of the pelvis but for testing the impact of the correction on pelvic control we often rely on the subjective experience of the patient.  Next time you are in this situation, try this.  Correct the two thoracic rings, have them reset the feet (this piece is missing in the first two videos as well and this can have huge implications for the hips and thus the pelvis through the pelvic floor) and then squat to get a sense of change – THEN – have them stay in the squat and release the thoracic ring corrections.  If the pelvis alignment and control has been restored by the thoracic ring corrections both you and the patient will see/feel an immediate change when you let the correction go – very confirming.

Nice, I can see I need to do more work correcting and releasing the correction of the driver/s through the different stages of each meaningful task. This will give both my patients and I another confirmation we are intervening in the most appropriate region of the body.

Language for the hook cue and segmental multifidus.  I like to open the conversation with something like this – you can’t strengthen a muscle your brain isn’t using so the first thing we have to do is ‘reconnect your brain’ to this muscle – multifidus – that is necessary for stopping this thoracic ring from translating/rotating.  Then do a ‘load effort’ analysis and show them how different that task feels when they engage the appropriate segmental DMF – buy in for Stage 1 training!

Thanks Diane. Yes, the language we use is essential to motivate our patients to be engaged in their rehab. I find this region (the thorax) of the body is particularly challenging when comes to training segmental control. Thank you for your wise words to help facilitate this process with my patients!