Laurie's Blogs.

I came across an interesting abstract.  It was a meta-analysis of papers on the subject of stretching and knee osteoarthritis (KOA), and it also took into account other forms of therapies into their analysis.  The findings were interesting, and of course, I like to take such things to the dogs and wonder how we can use this information to inform how we formulate our treatment plans.  

Let’s dive in!

The Paper:

Luan L, El-Ansary D, Adams R, Wu S, Han J. Knee osteoarthritis pain and stretching exercises: a systematic review and meta-analysis. Physiotherapy. 2022 Mar;114:16-29.

Objective: To evaluate the effectiveness of stretching exercises for pain relief in individuals with knee osteoarthritis (KOA).

Data sources: Nine databases (PubMed, Embase, Cochrane Library, Web of Science, EBSCO, PEDro, CNKI, WanFang and CQVIP)

Study selection: Randomised controlled trials (RCTs) involving stretching exercises conducted on individuals with KOA were included.

Results: In total, 373 studies were screened, with a final selection of 19 RCTs involving 1250 participants; of these, 18 RCTs were included in the final meta-analysis.

Conclusions: Stretching exercises can be useful in pain management in individuals with KOA, especially when used alone. Programmes involving both stretching exercises and other exercises may improve function but may not achieve a clinically effective reduction in pain.

The conclusion was interesting to me… so I sourced the whole article to find out more.  Why did the inclusion of exercise not have the same clinically effective impact on the reduction of pain?

Here’s a bit more to that story from the Discussion section of the paper:

1.  Proposed theories on why stretching resulted in reduced pain.

• Stretching exercises may alleviate musculoskeletal pain by decreasing muscle tension and improving metabolism within the articular capsule.
• Patients may respond to pain with muscle tension, and tend to avoid physical activity in an attempt to prevent pain, so the peri-articular connective tissue becomes fibrotic due to immobilization or inactivity.
• Adaptive shortening of muscles and capsular adherence can also be implicated in pain, stretching exercises could be effective because they can cause relaxation of the muscle fibres, thereby increasing muscle length and obtaining more adequate muscle tone.
• Articular cartilage loading during stretching exercises promotes exchange of nutrients in the cartilage and increases blood circulation in surrounding tissues, which may decrease inflammation and relieve pain.

2.  Why was combining exercise to the regimen of stretching statistically significant but clinically questionable for pain relief?

• One possibility is that the addition of other exercise modes of varying intensity and frequency may exacerbate the symptoms of KOA.
• During a strengthening programme that targets the lower limb, contraction of the quadriceps may increase the compression load on the patellofemoral joint and its associated cartilage.
• An imbalance in muscle activation timing between the vastus medialis oblique and vastus lateralis of the quadriceps femoris muscle group can also lead to abnormal loading of the patella and produce pain.
• Prolonged exercises at high intensity for participants with painful KOA may also overload the knee joint and further aggravate pain.

3.  There were two studies that looked at combining therapeutic modalities (pulsed laser, acupuncture, transelectrical nerve stimulation, ultrasound and infra-red)  and stretching.  The meta-analysis outcomes of pain scores showed that pain was relieved slightly when stretching exercises were added to treatment with physiotherapeutic modalities.

My Thoughts:

These are very interesting findings and hypotheses.  When it comes to using this information clinically in our canine rehabilitation practices, my take-aways are these.

1.  Stretching alone can help with pain.  This is great news especially for the severely affected dogs with OA.

2.  Adding exercise needs to be well-thought-out, specific to the patient, and targeted to address the specific needs (i.e. areas of weakness) of the target tissue.  

3.  Generic exercise might not be as beneficial as we think, and we need to be mindful in our exercise-prescription of ‘how much’ (or how fast,  how hard, or how long) exercise is administered or prescribed.

4.  Perhaps we need to structure our therapies (i.e. within a session or within a program) so as to firstly address pain (i.e. stretching or physiotherapeutic modalities), then move on to addressing function (i.e. specific targeted exercise), and finally move towards the goal of overall increase in exercise tolerance and capacity (i.e. longer walks on land or more time in the underwater treadmill).

What do you think?  I’d love to hear your thoughts!

Cheers,  Laurie