Physical therapy doesn’t help hip osteoarthritis?

Posted on November 9, 2015

(Last Updated On: March 27, 2016)

I’m a fan of the site Doctor Skeptic. The thesis of the site being a lot of the treatments we perform are ineffective when measured against placebo. That we aren’t doing enough research to see how many treatments fit under this umbrella. That the ethical considerations here are hypocritical. “It’s not ethical to do a study and deprive people of a treatment.” But how ethical is it to perform a treatment on people without knowing how efficacious it is?

He or she recently profiled the following study:

Effect of Physical Therapy on Pain and Function in Patients With Hip Osteoarthritis

The Skeptic doesn’t tend to go into much detail on these studies. It’s more to illustrate the continuance of the thesis, and bring more awareness that, in the least, something wrong is going on. I figured I’d delve into this one as it’s in my wheelhouse to some degree. (I’ve done this before here and here.)

What the study found

“Among adults with painful hip osteoarthritis, physical therapy did not result in greater improvement in pain or function compared with sham treatment, raising questions about its value for these patients.”

Right off the bat here, we need to say,

  • This study potentially makes physical therapists *not* look good, at least not the ones used in the study.
  • There is a lot going on here. The conclusion is not as clear cut as made out to be. (By the authors, nor those who’ve written about it.)

Issues with methodology

Even the authors go (bolding is always mine),

The rigorous methodology is a strength of our study. We minimized potential for bias by including a credible sham treatment, concealing treatment allocation, and blinding the participants, outcome assessor, and biostatistician.”

Talk about some confidence! The hallmark of research is a randomized, double blinded study. This study is not double blinded. It ain’t that rigorous. The physical therapists knew what therapy they were giving, as the sham treatment was “inactive ultrasound.” Plus, you know whether you’re exercising someone or rubbing gel on them.

Is this really a sham?

The exercise group received manual therapy, where the sham group did not. It’s not tough to make a case that rubbing a gel on someone’s hip, which is what was done in the “ultrasound,” is a form of manual therapy, as that’s essentially massage therapy.

We need more sham trial research, but a true sham trial, in certain arenas, is hard to pull off. If someone gently rubbed an area that had been bothering you for a while, that constitutes a treatment, and is often what any massage or manual therapy is. While not every therapist, many are rubbing around aimlessly.

Lots of variability

“Eight physical therapists (with ≥5 years of clinical experience and postgraduate qualifications) in 9 private clinics were trained to deliver both treatments.”

That’s a lot of physical therapists carrying out this study. Meaning that’s a lot of potential (guaranteed) variability in how all the treatments were given. The authors even quote their study as “semi standardized.” I see this semistandardized treatment as a flaw in the study. In the supplemental index, for the active treatment, three mobilizations were mandatory, as well as deep tissue massage of the entire hip and thigh. The therapists could pick between 3 and 6 sets, and 2-5 minutes of massage. Some therapists may have had double the volume as others.

Optional, was 16 mobilizations, between 3 and 6 sets. Also optional were various strength exercises, and more. One person could have had 16 extra mobilizations and 6 sets extra per mobilization compared to someone else.

Here was the list of functional balance exercises done-

hip pain balance exercise list

“Mandatory to include at least one.” One person could have done one, while another did 21.

While we may be comparing patients who did physical therapy to a quasi-sham treatment, within that, if we consider each exercise to be a letter in the alphabet, one person may have done the first 13, while another did the last 13. Sure, both might be able to spell something akin to “physical therapy,” but they can’t come near spelling the same words as one another.

An odd exclusion

“Major exclusions were hip or knee joint replacements or both, planned lower limb surgery, physical therapy, chiropractic treatment or prescribed exercises for hip, lumbar spine, or both in past 6 months, walking continuously more than 30 minutes daily, and regular structured exercise more than once weekly.”

I understand excluding those who are already exercising to some degree, but I’m not sure about excluding even walking for 30 minutes a day. Being inactive in itself isn’t great for pain, or practically any health measure. I wonder if the results would have been better (for both groups) if general activity wasn’t excluded and or encouraged.

Furthermore, even though the study went after pretty sedentary people, the average step count per day was about 7500 for all subjects. That’s pretty damn active for people who are doing zero exercise, and don’t walk more than 30 minutes at a time.

Even weirder, after implementing exercise for 13 weeks, both groups had less steps per day than when they started out.

hip pain title for step count hip pain step count

But after the 13 weeks, after the intervention, the active group got more steps again.

Meaning the exercise group appeared to have compensated for a benefit of exercising -more movement- by generating…less movement. From a pure sedentary perspective, the exercise group didn’t get any benefit, which is important because you tend to find more active people are healthier all around, pain and function included.

This may be more strange than anything, but we’ll come back to it.

That said,

The above doesn’t necessarily cancel out some things this study found.

The point of exercise is to…

Improve on some measure. Often, this is strength and endurance. Pain is another common measure.

The subjects were one on one with the therapists on average 10 times in 12 weeks. Less than once per week. This isn’t much feedback. My experience with new clients is most need feedback a minimum of once per week. And that once per week clients very, very rarely do as well as twice or three time per week clients.  This is irrespective of how long I’ve had the client. The study started out with patients twice per week for a week, then tapered that down, averaging out to 10 over 12 weeks. But what I’m saying is it doesn’t matter if I’ve had you for four years, if you move down to once per week, you typically don’t do as well.

  1. Adherence goes down, no matter what the person says. (This study asked people to report their adherence. I’ve talked about issues with asking people about their behavior before.)
  2. Effort goes down. People aren’t as diligent nor do they work as hard when someone is not regularly working with them.

-> I find this happens sometimes even if I’m in the gym with the client! The moment I don’t look at them for a couple minutes, form may fall off.

But let’s get away from the methodology. One way we can tell whether this was enough feedback is to look at the improvements the subjects had. Pain wise, per the conclusion, we know the sham group did just as well. How about strength wise though? Or endurance wise? A fake ultrasound shouldn’t be comparable in these regards, right?

Hip pain exercise improvement 1 Hip pain exercise improvement 2

Looking at quadricep strength-

  • Exercise group went from 1.29 to 1.41, a ~9% improvement.
  • Sham group went from 1.32 to 1.37, a ~4% improvement.

Hamstring strength-

  • Exercise 0.70 to 0.73, a 4% improvement.
  • Sham had 0% improvement.

More specifically at the hip, hip flexion strength-

  • Exercise 0.98 to 0.99, a 1% improvement.
  • Sham 1.01 to 1.03, a 2% improvement.

Sit to stand test (how many times can you sit up and down in 30 seconds)-

  • Exercise 9.4 to 10.7, ~12% improvement.
  • Sham 9.8 to 10.7, ~8% improvement.

Timed stair climb-

  • Exercise 8.6 to 7.9, ~8% improvement.
  • Sham 8.2 to 7.4, ~10% improvement.

This is three months of exercise we’re talking about here. Compared to doing no exercise, the exercise group often only improved by ~4%? Hip flexion strength, something that often should be significantly worked on in hip pain, improved by 1%? In some cases the exercise group did worse than the sham group? On an exercise measure???

We either have,

1) Adherence must not have been very good.

My experience is exactly the above. For in person clients on a once per week session basis, new ones often only exercise once a week, despite what they tell you, and once a week exercise is a recipe for exercise measurements improving marginally, if at all.


2) What in the world were these physical therapists doing?

If you take someone who is sedentary, and have them start doing damn near anything on a regular basis, they’ll get better. It doesn’t matter how terrible the program is, strength and endurance tend to improve, because the baseline is so low.

Putting this another way. Your first day you come in and bench press 100lbs. Three months later you’re able to bench press, maybe, 104lbs. What kind of progress would you consider that??? How would you feel if three months later someone who did zero exercise also improved that amount? Usually you can progress someone, a minimum, of 5 pounds a week the first few months. Meaning by week two someone should be able to bench press 105lbs! (Improve 5%.)

Or here is a random study I found:

Effects of Maximal Isometric and Isokinetic Resistance Training on Strength and Functional Mobility in Older Adults

Three months of training in older people.

Older people strength improvement

Those numbers are all a lot bigger than the ones in this current study. Plus, the above subjects average age was about 72, where the ones in the hip study are about 63. If anything, improvement should be worse with the 70+ crowd.

Which is why I lean towards adherence likely being way worse than the authors believe. They remark adherence reported as 85%. If that’s truly the case, then this is an incredibly poor exercise program. The therapists were instructed to progress exercise difficulty, but this clearly couldn’t have been done. Three months of exercise and you do worse than someone who didn’t exercise, on an exercise test? And these are basic exercise tests. We’re talking getting out of a chair or going up a flight of stairs. It’s not like you could say, “Well, these people were also marathon running, which could negatively impact maximal strength.” We’re nowhere near that type of discussion.

To be fair, maybe it was the people who designed the exercise program, opposed to those who carried it out. There were only two mandatory strengthening exercises. A hip abduction exercise and a quadricep exercise. All others were optional.

Hip pain exercise selection

When only 27% of people are performing gluteal exercise for a hip issue, we have a problem. If anything, the glutes should have been mandatory and the quadriceps optional. Why would strengthening the quads be a primary focus in a hip issue? The quads don’t even connect to the femoral head.

Not many did any of the optional strengthening work. For that, the blame is on the therapists. Thinking 3 sets of 10 of hip abduction and quadricep work is going to do much for hip pain is on them.

By the way, I’m not sure we have any idea how often the optional exercises were done. One time? Ten times? Every session? One week but not the other 13? When the patient wanted?

Pain outcomes

One reason this is important is because exercising only once a week or less is a good way to have exercise cause pain. After you exercise you have about about 48 hours you’re typically weaker. From there, it’s about another 72 hours you’re stronger than that first session. After this, you start getting weaker again.

  • Squat on Monday.
  • Tuesday and Wednesday you’re weaker than you were on Monday (if you tried to squat again).
  • Thursday, Friday, Saturday, maybe Sunday, you’ll be stronger than you were Monday (if you try to squat again).
  • ~Sunday / Monday; you’re just as strong as you were last Monday (if you haven’t squatted since).

This is why the optimal training frequency per body part is about once every five days. Or twice a week for practical purposes. It’s why you see optimal training splits be something like (as one example),

  • Monday / Thursday legs
  • Tuesday / Friday upper body

If you wait and only do things once a week, well, we all know what exercising after not exercising for a while feels like. Painful. This is one reason we shouldn’t be surprised by this,

“19 of 46 (41%) in the active group reported 26 adverse events vs 7 of 49 (14%) in the sham treatment group reported 9 adverse events. All were mild and transient, comprising increased hip pain or stiffness or pain in the back or in other regions.”

The other possibility for this increased pain is the manipulations being done. For instance, one mandatory mobilization required placing the hip in maximal internal rotation range of motion. Placing a pissed off joint in maximal range of motion might tick it off…

The authors mention medication use was similar for both groups. Over the 36 week timeframe of study it was pretty similar. But it wasn’t during the three months the subjects were seeing a therapist.

15% greater analgesic use, and 27% greater NSAID use in exercise group. Greater usage was found at 36 weeks too, although not as much of a discrepancy. (Also, oddly, a lot more glucosamine / chondroitin use in Sham group. This should be taken into consideration!)

15% greater analgesic use, and 27% greater NSAID use in exercise group. Greater usage was found at 36 weeks too, although not as much of a discrepancy. (Also, oddly, a lot more glucosamine / chondroitin use in Sham group. This should be taken into consideration!)

Again, either

1) Adherence was not good

-> That above chart elucidates this some more. For home exercise, week 0-13, the

“Number of home exercise sessions completed as recorded by participants in a log book (out of a maximum of 48 and converted to a percentage).”

That number is 3.4. Either the authors meant “Number of homes exercise sessions completed per week…” as 3.4 / 4 = 85%, what the authors say adherence was, or they made a big mistake here.

Because as written it would mean over the course of 13 weeks, 9.6 + 3.4 = 13 sessions were performed. Or basically once per week. (Fitting with the one time per week theory above.)


2) What were these physical therapists doing? Why were so many people having painful episodes? Nearly half the exercise group had one or more adverse events.

Some pain here and there is common

When people are exercising and they haven’t been, some odd sensations are going to happen. It’s rarely where someone just linearly gets better. They often are getting better, getting better, have a minor pain setback, getting better, small setback, getting better, getting better, etc. This is more true for people who have been sedentary.

Some of the criticism I’ve seen of exercise in this study is those who exercised had more painful events. I’m not sure how fair a criticism this is. Part of getting out of pain is working your way through it. Testing the waters. Sometimes you’re going to push that line too far. So long as it’s “minor and transient,” I’m not sure it’s worth fretting over much.

-> As the practitioner you still do everything possible to avoid pain though. It’s not to be taken lightly. I don’t believe this was as well done as it could have been in the study. That said, there are limitations to what one can predict will cause pain.

However, due to the lack of improvement in all exercise measures, I lean towards

  • adherence being a problem,
  • therapists probably pushing their patients too much mobilization wise,
  • therapists likely not pushing their patients too hard exercise wise (based on exercise improvements, they couldn’t have pushed them that hard!)

People did improve

It’s important to note whether it was exercising or the sham group, people did get better. Quite a bit better. So, it’s not that exercise did not improve things. It’s that it didn’t offer an additional benefit compared to the sham group.

But that’s not typically how exercising goes. Not only did these people exercise for three months with sporadic therapist interaction, they exercised a total of nine months. No extra benefits from nine months of exercise?


Why did they improve?

It’s tough to know. Both groups involved some form of another person rubbing on their body. The sham group had the fake ultrasound; the active group had various manual therapy techniques.

Both groups also had interaction with a presumably understanding therapist. How you interact with people is very importantBut,

A minor hit to pain science?

“Treatment credibility ratings after the first treatment sessions were significantly higher in the active group than in the sham treatment group, indicating greater participant confidence in his/her treatment and its effectiveness but were not different after the last session.”

The pain science lords will gladly glug a gallon of water and piss on everyone with showers of “how much one believes in the treatment matters; relationship with the therapist matters.” That we can’t only look at the “damage” element. Well, you can’t only look at the brain element either. The belief element either. The therapist interaction element either.

Credibility was higher in the exercise group to start, but this eventually waned. Why did it wane? I don’t think it’s tough to imagine because results were not different. That as the treatments progressed, and the results were similar, the minds started to match the results. That the results dictated the thinking. The behavior dictated the attitudes. Because it clearly didn’t happen the other way around!

-> This is a hallmark of cutting edge 21st century behavioral change, by the way. (See BJ Fogg at Stanford.) It’s where the obsession pain science has with education is misguided. Just look at weight-loss as a prime example. Educate people all you want about nutrition, carbs, protein, how many calories are in something by placing calories numbers in all restaurants, how being overweight is bad for heart disease, diabetes, even fertility, and you get a country that’s still getting fatter. Knowledge does not equal behavioral change. It can help as a factor, but as one factor.

How you feel about your pain is one element. Just like biomechanics, just like alignment, just like an abnormal MRI, just like “joint damage,” just like whether you suffer from depression or not.

A minor hit to manual therapy (and subsequently pain science again)?

After 13 weeks, subjects were left on their own. For those exercising, they were instructed to keep up with their routine on their own. For those in the sham group, they continued to rub some gel on themselves, to simulate the ultrasound.

What happened after 13 weeks?

Hip pain 13 week and 36 week

-> You may be wondering, for function, the active group had 12% more people improve, and 11% more people maintain this improvement. That wasn’t statistically significant? I believe what the authors did was calculate improvement rates based on the amount of improvement for the score, not the percentage of subjects who improved. So, how much did function improve? Not how many people improved. I haven’t worn my stats hat in a while, but 12% is a big difference for it to not be statistically significant.

The pain science crowd will be quick to jump here and go, “See! Look what happened once the patient was removed from their therapist interaction! Their scores went down!”

But who is never going to be removed from their therapist interaction? Short of the chiropractic route, where you tell people you need to adjust them at regular intervals, we all come to the point where the patient / client is on their own. For physical therapists in America, you will pass almost every client you have to be on their own at some point. If it’s not completely on their own, then you’ll only be seeing them every so often. Maybe once every week or two. That’s hardly an active intervention. They’ll need to be doing something themselves.

This is where we again come back to adherence. You can exercise on your own. You can’t do manual therapy on your own.

Why did the exercise group improve? We have a hard time saying it was anything from the exercise, as the exercise didn’t seem to change much of anything. We could say it was patient interaction, sure. But what about manual therapy? The exercise group received manual therapy as well as exercised. Maybe the manual therapy helped the improvement? Like it did in the sham group?

And what happened once the therapists touch interaction was removed? Scores went down.

And what is the reality of the real world? You can only touch someone so often, for so long. And getting a person to where they feel they need to see you regularly is not something conducive for the person. (It’s conducive to your business, that’s it.) You want people to not need anything but their own devices. You cannot, cannot, cannot pull this off with manual therapy. Whatever improvement you might give someone will very likely dissipate the moment they stop seeing you.

A definite win for pain science

I was surprised to see the active group had patient education. It consisted of,

Patient education hip pain physical therapy

Pain science is big on properly educating people, and it’s something they’re spot on about, in that proper education is needed. (They’re off in thinking it will be sufficient.) Within that, they’re really trying to get people to move away from terms like arthritis -as it’s become synonymous with pain (it is anything but)- using terms like damage, worn out, those types of things. It seems they’re correct this time in illustrating using this type of approach is still a hallmark of physical therapy. I’d be shocked if an accurate representation of what causes pain was given to these patients. (Remember, this is the active group.) If anything, their education may have made things worse.

The overall conclusion isn’t quite correct

“A multimodal physical therapy program conferred no additional clinical benefit over a realistic sham for people with hip osteoarthritis…”

I’ve used the following rationale two years ago. It bears repeating:

By Joel Pett of USA Today.

By Joel Pett of USA Today.

Let’s say exercise truly doesn’t offer any extra benefit for hip osteoarthritis related pain. You exercise to get rid of your hip pain, but your pain doesn’t dissipate more than fake ultrasound with a therapist. All you get is,

  • Improves your chances of living longer and living healthier
  • Helps protect you from developing heart disease and stroke or its precursors, high blood pressure and undesirable blood lipid patterns
  • Helps protect you from developing certain cancers, including colon and breast cancer, and possibly lung and endometrial (uterine lining) cancer
  • Helps prevent type 2 diabetes (what was once called adult-onset diabetes) and metabolic syndrome (a constellation of risk factors that increases the chances of developing heart disease and diabetes; read more about simple steps to prevent diabetes)
  • Helps prevent the insidious loss of bone known as osteoporosis
  • Reduces the risk of falling and improves cognitive function among older adults
  • Relieves symptoms of depression and anxiety and improves mood
  • Prevents weight gain, promotes weight loss (when combined with a lower-calorie diet), and helps keep weight off after weight loss
  • Improves heart-lung and muscle fitness
  • Improves sleep
  • Helps with dementia
  • Helps with parkinson’s disease
  • Benefits fibromyalgia patients
  • Improves self-esteem
  • Strengthens immune system
  • Reduces inflammation
  • Impacts basic cognitive function, such as learning and memory.
  • Decrease macular degeneration (helps with eyesight)

By the way, you still get a pain reduction. What if you exercise and all you get is [list of endless benefits]?

This is where the “no additional clinical benefit” over fake ultrasound isn’t exactly accurate. I think the authors may have given themselves an out with the “clinical benefit” remark, but you can’t discount what exercise can do in other respects.

hip pain title for step count hip pain step count

We looked at this earlier. While the numbers at 13 weeks are odd, the numbers at 36 weeks may have some significance. In the least, the active group is more active than the beginning of the trial, where the sham group is a thousand less steps active, and seemingly trending downwards.

Is reduced risk of heart disease not a “clinical benefit?” The authors looked at osteoporosis / osteopenia rates between groups, exercise can help that, is that not a clinical benefit? Reduced risk of diabetes? Possible weight loss? Strength? Endurance?

Which is again why the lack of and or marginal improvement in practically every exercise oriented element is disturbing in this study. It means you can’t say much about the exercise program’s benefits other than it offered barely any. (If the exercise did offer some significant benefit, those who exercised may have gotten a greater pain reduction.) In the least, if people are exercising, particularly when compared to people who aren’t, they should clearly be getting more steps per day, getting stronger, getting more endurance, it should be easier to go up and down a flight of stairs, easier to get up and down out of chair. For a sedentary person, after months of exercise, these things should all improve demonstrably. Something didn’t go right with this study’s exercise program.

-Effect of Physical Therapy on Pain and Function in Patients With Hip Osteoarthritis

A better title for the study,

-Effect of Nearly Futile Physical Therapy on Pain and Function in Patients With Hip Osteoarthritis

Giving us the conclusion of,

“A minimally effective multimodal physical therapy program conferred no additional clinical benefit over a realistic sham for people with hip osteoarthritis…”

I’m not sure how many people would even click that link?

“…Interacting with a therapist can give pain reduction in itself, particularly when the therapist is touching you.”

Sooo, people like to be rubbed and have conversations?

“Furthermore, in our first group, interacting with a therapist who touched the subjects offered the same benefit as in our second group, who interacted with a therapist touching them.”

Hot damn, this really is the golden age of understanding the human brain.

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Posted in: Hip Pain, Pain