Category: Research

I’m always amazed at how millions of individuals use similar movement strategies during normal human development.  No one invents a new way to stand up or walk or crawl, as our brains seem to instinctively know the most efficient way to move our bodies around.  But, it seems we may be wired to learn how to stand properly only one time in our lives! 

Well, that may be taking this a little too far, but a recent research study out of the University of Delaware found that in patients with Total Knee Athroplasty (TKA), learning to stand normally is certainly not intuitive.  It is a research study which has personal implications for me, though I’ve never had a knee replacement.

Investigators wondered why patients with knee arthroplasty continued to demonstrate reduced scores on functional movement tests despite reduced pain and normalized strength.  To try to answer the question, the research team analyzed a sit-to-stand task, measuring joint angles, ground reaction forces and other variables of the motion.  The subject group compared patients with TKA to age-matched controls up to 1 year after the procedure.

The surprising result was that even as the quadriceps muscle strength normalized, patients continued to use substituted patterns of movement.  When rising from sitting to standing, patients with TKA relied on less quadriceps muscle function and more hip extension muscle activity.  They achieved this reduced quad requirement by beginning the transfer with a greater amount of hip flexion compared to controls.

The significance of this is that physical therapists must be aware that, even in the face of normalized muscle strength, patients after TKA may need to be specifically trained in the transfer in order to perform it correctly.  I wonder why the body doesn’t use the quad in the pre-injury manner on it’s own? Are we only wired once?  Is there some inhibition of the quads that persists for a good reason?  Is it related to TKA, or is this phenomenon present after all knee surgery?

Personally, I find I use my hip extensors most of the time in my very injured knee.  I notice this while climbing stairs and, especially, while cycling on my road bike where the smallest movement of the seat completely saps my power. 

By the way, this study has been getting nice pick-up by the press, even earning a feature in the LA Times.

 

Farquhar, S.J., Reisman, D.S., Snyder-Mackler, L. (2008). Persistence of Altered Movement Patterns During a Sit-to-Stand Task 1 Year Following Unilateral Total Knee Arthroplasty. Physical Therapy DOI: 10.2522/ptj.20070045

Last week a very interesting discussion took place on the Orthopaedics Discussion Group on MyPhysicalTherapySpace.com.  The discussion was provoked by the abstract listed after the break, and specifically the following statement:

"The clinical prediction
rule proposed by Childs et al. did not generalise to patients
presenting to primary care with acute low back pain who received a
course of spinal manipulative therapy."

Description of the CPR in question on YouTube

MyPTSpace is a free online community and this debate sure showed how valuable community discussion can be.  This conversation was priceless and reminded me of a recent PT Journal Debate between Tim Flynn and Chris Maher, except in more of a WWE RAW style!

Central to the discussion is the question of whether or not the CPR applies to populations outside of those used to develop and study it thus far.  Just about all of the authors of the studies up for debate checked in.  One important hot topic was the fact that the researchers proposed to study the CPR as "proposed by Childs et al" but only used high-velocity thrust manipulation in a small percentage of patients, as opposed the the 100% utilization in the Childs’ study.  This discrepancy provided fuel for the debate as the question was asked, if the researchers applied the rule correctly.

Many chimed in with comments. Most notably, Josh Cleland provided a list of the points he’s pondering:

"I appreciate the dialogue on
this topic. I think we all can appreciate the efforts put forth by both
the Childs team and that of Hancock and colleagues. Certainly I have a
bit of bias here but after critically and objectively analyzing both
articles I walk away with a few thoughts.
 
1. Perhaps the CPR is only specific to thrust manipulation and not to non-thrust techniques.

2. Perhaps the CPR is only specific to the thrust technique used in the original study and not other thrust techniques.

3. Perhaps the CPR doesn’t apply to patients who are not recruited
from a military setting (we can argue the generalizability of this for
days)
4. Perhaps the exercise used in the Childs study was crucial to success.

5. Perhaps the lack of standardization of techniques is a recipe for failure.

6. The Hancock study does not test the CPR as it was originally developed.

7. Perhaps the rule doesn’t predict response to thrust manipulation
(although the Hancock results to do provide adequate evidence to
suggest this)."

Josh’s summary was generally accepted by all the debaters as a balanced viewpoint.  Though there were some other interesting points made as well…

"However, I do find your “more blind faith” comment a bit patronizing and yes, I have read both papers."

"While the scientific method
is intended to provide control, minimize confounding factors, and limit
our biases, we still bring our biases into our scientific endeavors
(including published papers). With this in mind it is helpful to remind
ourselves that clinicians and researchers will generally agree much
better on data than inferences drawn from the data."

"So- evidence exists to
support the use of thrust manipulation in the management of a
particular subgroup of patients. However, therapists in Australia who
are well aware of the evidence fail to use it (even when they were
instructed that they had to use manual therapy). I expect if we gave
therapists control of which techniques to use here in the US we would
see the same magnitude of under utilization."

"…I’m sorry you apparently don’t like chicken sandwiches.  😉  It might just be an American thing…"

"Given you don’t use plain
language words as they are defined in English dictionaries and others
do not use scientific terms as they are defined in scientific texts it
is unlikely we will ever understand each other, let alone reach
agreement."

This was all great fun and if you want to find out who said what in the above statement, go see for yourself. [Link to Discussion]

And here’s one last quote, which I think should be pondered for a while:

"It might just be me, but one
of the reasons I think that the Hancock study has resulted in this
level of discussion is the rather sensational quality of the statements
within the abstract."

I hope you didn’t mind the long post, it was fun for me!
ERIC

(Click on to read the abstract)

Continue reading “MyPhysicalTherapySpace Goes RAW!”

As a physical therapist on the forefront of the profession’s movement towards autonomous practice, I often find myself confronted with the fact that physicians don’t have a blue print of APTA’s Vision 2020 in their daily planner.  Which means that sometimes a physician will treat a physical therapist more like a worker than a professional.  On one side of the spectrum, and similar to my experience working in the Army health care system, some physicians treat physical therapists as colleagues, often asking for input on patient appropriateness, diagnosis, and dictating open-ended referrals.  Alternatively, and not 20 miles down the road, I live near some very conservative, old southern physicians who would gladly have me shine their shoes and wax their car when I’m done applying the moist heat and ultrasound.  I expect the norm across the United States lies somewhere in between these two extremes. 

The opinions of most physicians can be observed in the type of referral they write to physical therapy.  I either get an consult-ish, "evaluate and treat" open referral, or a more prescriptive, "3x/week, 4 weeks, hot pack, ultrasound, strengthening" referral.  From my perspective, I only need the first kind, as I know how to do my own job.  A prescriptive consult between physicians is unheard of.  Imagine a family medicine doc sending a referral to an orthopaedic surgeon that read, "Shoulder pain, instability, please perform capsular shift and progress with conservative strengthening protocol over 8 weeks!"  The open consult is more consistent with autonomous physical therapist practice.

How can we reconcile these two types of physician referrals?  I am strongly biased towards the open referral type, but can research tell us anything about which of these two attitudes result in the best patient care?  Gary Brooks and colleagues hypothesized that a prescriptive referral would result in a higher utilization of resources by reasoning "that prescriptive referrals oblige therapists to negotiate patient management issues with physicians, creating a greater administrative burden that may be reflected by a higher number of patient visits."

In their research, which was limited by a very low inclusion of patient records (6.8% of eligible subjects) this hypothesis was not supported.  What they did find, was that the type of referral was not associated with number of visits, but was attached to a greater level of discharge disability.  This study can then add to the argument that a prescriptive referral is of no extra help in the provision of physical therapy services, and might be associated with poorer patient outcomes.

I would have liked to see a greater sample size, but this was limited as most eligible records were incomplete due to patients not completing their physical therapy sessions and so discharge data was often missing.  That is a shame, because research like this can really help to reconcile some differences with physical therapist-physician relationships.  I wonder if the subjects in the study had deemed themselves ready for discharge prior to the physical therapist considering them as such.  If so, did this study churn up a practice pattern of generalized over-utilization by physical therapists as they string out patient visits?  It’s possible, and much more likely when the physician dictates an arbitrary number of visits irrespective of patient progress.

My conclusions:  I continue to consider open referrals more appropriate, with some small exceptions for post-surgical protocols of complicated surgeries.  I now have this bit of research in my pocket that tells me the prescriptive referral is at least no better.  I look forward to more research of this type that also delineates the differences when physical therapist expertise is factored into the mix.

As an aside, when I posed the question that is this post’s title to one of my first year PT students, she reflexively responded, "NO!"  I look forward to the day when a medical student might answer the same question in the same manner.  Then, we would be getting somewhere.

ERIC

Brooks, G. (2008). Is a Prescriptive or an Open Referral Related to Physical Therapy Outcomes in Patients With Lumbar Spine-Related Problems?. Journal of Orthopaedic and Sports Physical Therapy, 38(3), 109-115. DOI: 10.2519/jospt.2008.2591

The latest edition of JMMT is up and marks the final issue that Dr. Peter Huijbregts will serve as Editor-in-Chief.  As always, JMMT gets my nod for having full-text access to non-subscribers and an RSS feed for those fans of aggregation software. 

The open-access material for this issue includes a case report by Borgerding et al describing the use of the patellar-pubic percussion test (http://jmmtonline.com/documents/v15n4/BorgerdingV15N4E.pdf) and a research paper by Tucker et al on the reliability and measurement error of a modified slump test (http://jmmtonline.com/documents/v15n4/TuckerV15N4E.pdf). Other free online content accessible at http://jmmtonline.com/current/ includes the editorial, book and multimedia reviews, a thesis review, letters to the editor, an obituary for Dr. Joe Keating Jr., and an author and subject index for volume 15.

I recommend Peter’s editorial, although it surely does not top the ‘Chiropractic Legal Challenges’ manifesto.  He discusses a model of OMPT research, and includes a brief statement against "evidence-driven totalitarianism" in clinics as it pertains to utilization of research findings.  I will miss eagerly anticipating the next editorial, and wish Peter all the best in his next adventure.  "Tot ziens en bedankt."  Likewise, I’m looking forward to the stewardship of new Editor-in-Chief, Dr. Chad Cook.  Good Luck!

ERIC

"Need New Knees?  Now May Be The Time, " was the title of a press release by the American Academy of Orthopaedic Surgeons last week.

"These results suggest that we might be waiting too long to suggest
total knee arthroplasty as a treatment option for women with end-stage
knee OA," says Stephanie Petterson, MPT, PhD, one of the study’s
authors and a senior lecturer at the School of Health and Bioscience at
the University of East London, "or that women with knee OA are waiting
too long to access the appropriate care."

Hey, marketing and research are two different things!  This is a good example of working them both.  The release reported the findings of this article in The Journal of Bone and Joint Surgery.  The basic gist was that women wait longer than men to seek care and so their outcomes may be worse after TKR.  Common sense, really.

Another interpretation might have been, "PT’s not helping prevent progression of knee osteoarthritis."  That’s not really science either, but surely must be a more wholesome recommendation than the press release encouraging a shopping spree for major surgery!

Petterson, S.C. (2007). Disease-specific gender differences among total knee arthroplasty candidates.. The Journal of Bone and Joint Surgery, 89(11), 2327-2333.

ERIC

Decades of clinical practice by manipulative providers have demonstrated the effectiveness of spinal manipulation as a therapeutic modality.  The truth is that the mechanism of exactly how manipulation is effective has remained out of reach and unexplained.  As research methods have become more sophisticated and the tool box of measures has increased in size, the prospect of figuring out a mechanism now seems a likely pursuit.

One handy tool that has become very popular in physical therapy research is ultrasonic imaging.  Just like any ultrasound study, the clinician is able to observe real-time events.  In the case of rehabilitative ultrasound imaging, the therapist is examining muscle activity.  Measures of muscle thickness can vary and observable changes have been associated with pathology.  For example, patients with low back pain show changes in cross sectional area of the lumbar multifidus muscle.  Likewise, other patients with back pain have been shown to have difficulty activating their transversus abdominis muscle. 

When this measure was used to study abdominal muscle thickness following a spinal manipulation procedure, an interesting thing occurred.  The abdominal muscle activation changed!  In a case series by Raney, Teyhen and Childs, spinal manipulation seemed to be correlated with a normalization of abdominal muscle recruitment patterns in patients with low back pain.

Perhaps this is a peek into the mechanism of spinal manipulation’s effects.  The subluxation concept aside, spinal manipulation may have more to do with muscle activity, spinal reflexes, and the neuromuscular system than it ever had to do with alignment of the bones.  The rapid, short duration of the motion used in manipulation does remind me of testing a deep tendon reflex!

Interesting to note, the researchers examined spinal manipulation in a group of symptomatic patients who met a criteria for a clinical prediction rule that identifies patients who are very likely to benefit from manipulation.  Also interesting to note, this case series appeared after an initial case report by different investigators.  They found a similar effect in another core stabilizer muscle in their report.  Finally, we’re talking case report and case series here, so true causality regarding the phenomenon will have to wait for now. 

This study is just one of many new investigations suggesting the role of spinal reflexes in the mechanism of manipulation.  We will visit them over time here on the blog, along with some interesting off-shoots of that research. 

Here’s the article abstract and citation:

Observed changes in lateral abdominal muscle thickness after spinal manipulation: a case series using rehabilitative ultrasound imaging.

Raney NH, Teyhen DS, Childs JD.

STUDY DESIGN: Case series.

BACKGROUND: A clinical prediction rule (CPR) has been developed and validated that accurately identifies a subgroup of patients with low back pain (LBP) likely to benefit from spinal manipulation; however, the mechanism of spinal manipulation remains unclear. The purpose of this case series was to describe changes in lateral abdominal muscle thickness using rehabilitative ultrasound imaging (RUSI) immediately following spinal manipulation in a subgroup of patients positive on the rule.

CASE DESCRIPTIONS: Data from 9 patients (5 female, 4 male; 18-53 years of age) with a primary complaint of LBP are presented. All patients had symptoms for less than 16 days (range, 3-14 days) and did not have symptoms distal to the knee, satisfying the 2-factor rule for predicting successful outcome from spinal manipulation. The Oswestry Disability Index scores ranged from 8% to 52%. Lateral abdominal muscle thickness was assessed with the patient at-rest and while contracted during an abdominal drawing-in maneuver (ADIM) using RUSI. Measurements were taken before and immediately after spinal manipulation. Patients completed a 15-minute training session of the ADIM prior to assessment, to mitigate the potential for a learning effect to occur.

OUTCOMES: Based on changes that exceeded the threshold for measurement error, 6 of 9 patients demonstrated an improved ability (11.5%-27.9%) to increase transversus abdominis (TrA) muscle thickness during the ADIM postmanipulation. Additionally, TrA muscle thickness at-rest postmanipulation decreased for 5 patients (11.5%-25.9%), while at-rest internal oblique muscle thickness decreased for 4 patients (6.4%-12.2%).

DISCUSSION: This case series describes short-term changes in lateral abdominal muscle thickness post spinal manipulation. Although case series have significant limitations, including the fact that no cause-and-effect claims can be made, the decrease in muscle thickness at rest and the greater increase in muscle thickness during the ADIM postmanipulation observed in some of the patients could suggest an improvement in muscular function. Future research is needed to determine if increased muscle thickness is associated with improvements in pain and disability and to further explore neurophysiologic mechanisms of spinal manipulation.

Citation:

Raney, N.H., Teyhen, D.S., Childs, J.D. (2007). Observed changes in lateral abdominal muscle thickness after spinal manipulation: a case series using rehabilitative ultrasound imaging.. Journal of Orthopaedic and Sports Physical Therapy, 37(8), 472-479.