On 13-14th of december 2019 EUSSER held a congress in the Netherlands, focussing on the importance of the brain in pain mechanisms.
The congress kicked off with a lecture of Ghent University colleague Iris Coppieters on “Understanding pain”. Her take home messages were:
- Pain is always a subjective experience that is influenced to varying degrees by biological, psychological and social factors
- Chronic pain is not simply a continuum of acute pain
- There is structural and functional reorganization of the brain in people with chronic pain
- Brain circuits involved in acute and chronic pain differ with a shift from nociceptive to emotional circuits in chronic pain
- Learning about pain is the first important step for patients, health care providers and society
Jo Gibson built further on this stating that patients pain beliefs impact the way they move and that these pain beliefs are modifiable. First, being a confident therapist is crucial in this modification. The patient should believe in therapy to have a successfull outome. Second, therapist can work with reducing symptoms to reduce the threat. To do so, she suggests to use improvement tests. For example by using feedforward activation. By engaging the hand, the shoulder is ready for action. Another example is to shorten lever arm during shoulder movement, to activate the cuff to increase compression (using theraband) or to facilitate the scapula during shoulder movement. These improvement tests inform our exercise selection.
Furthermore she discussed the impact of daily stress triggers on pain perception and reminded us that patients experience less pain when they have something more important to do, so therapists should play with processing, distraction and cognitive bias. Using mirror therapy, using a task to override the protective strategy, using music during therapy or using lef-right judgement were some of the examples.
As a psychologist, Johan Vlaeyen informed the audience about psychological aspects of pain. Explaining the fear avoidance model, he explained how pain urges action. Pain is valued as a high or low threat by the brain and choices are made for action. The brain learns from pain and is becomes conditioned to anticipate potential averse effects. Extinction of threat is achieved by graded exposure.
In shoulder patients, the only real predictors for outcome are baseline pain and self efficacy according to the longitudinal study of Rachel Chester. She explained how a therapist can increase that personal mastery. She gives splendid suggestions on how to implement that in your practice. Some examples:
- Use video recordings of exercises for your patients, this remembers them that they can do it, they can control pain
- Use truthfull verbal persuasion and encouragement
- Reframe anxiety
- Have patients observe themselves or others successfully performing a task
- Break the cycle of fear: use mindfullness, breathing exercises, relaxation training, graded activities, touch for symptom modification,…
Kevin Kuppens held a lecture on “Shoulder pain orchestrated by the brain”. He discussed measures for central sensitisation. Pain pressure thresholds are an indirect way to measure central sensitisation and a low pain pressure treshold indicates hyperalgesia. However, the variation in PPT measures is huge and there is no clear evidence that PPT in patients with shoulder pain is lower. Clinicians must take into account that this measure is only an indication of hyperalgesia but no diagnostic tool. Good physiotherapy should entail 2 main components being 1) Active rehabilitation and 2) Good communication. Individual needs of the patient are key.
Some specific pathologies were discussed in the view of “brain and pain”: instability (By Gregory Cunningham) and frozen shoulder (by Liesbeth De Baets:
Gregory Cunningham dealt the question why there is prolonged apprehension after stabilisation surgery. He first discussed peripheral explanations like the presence of subclinical neurological injury after shoulder luxation besides the clinical injuries which are present in 14% of patients. Subscapularis splitting might also be a peripheral cause for maintaining apprehension. Besides peripheral explanation there might be an important role for central adaptations. Changes have been demonstrated in the ipsilateral sensorimotor cortex and the brain network for fear of patients after shoulder luxation. This brings us to the implications for treatment: treat the whole and incorportate brain-reafferention in treatment for example using biofeedback and cognitive behavioural training.
The impact of pain on the brain in frozen shoulder patients was explained by Liesbeth De Baets. She investigated the association of pain related beliefs and perceived arm function. She concluded from this study that range of motion is not related to catastrofizing, depression and pain beliefs. External rotation range of motion is only associated to the perimeter of the inferior recessus of the shoulder capsule and not to patient reported outcome measures. The other way around, patient reported outcome measures are not related to structural changes.
Abstracts were presented by Ghent University colleagues Dorien Borms and Kelly Berckmans and by Stef Feijen.
Some key points:
- Dorien Borms (@DorienBorms1) presented her RCT study comparing a more analytical strength training program with a more functional strength training program (kinetic chain exercises) in patients with subacromial pain syndrome. Equal clinical outcome was demonstrated so functional training does not have disadvantages for pain and function and is possibly preferred by a selection of patients to increase the “fun aspect”!
- Kelly Berckmans (@KellyBerckmans) presented her study investigating the “Kibler exercises” combining EMG and 3D kinematic analysis. This shows very nicely that changes in kinematics are related to changes in muscle activity. For example the inferior glide exercise elicits more anterior tilt in the scapula combined with higher activity of the pectoralis minor. To be continued as this paper was recently accepted in AJSM!
- Stef Feijen presented his systematic literature review and concluded that a large increase of training volume is associated with an increased risk for injury. Based on these findings it is recommended to educate the swimmer that shoulder pain is not inevitable and that they should learn how to self-regulate stress and training load. Physiotherapist should prescribe individual exercise programs for prevention.
In the free paper sessions Ghent University colleague Valentien Spanhove (@ValentienSp) was awarded by the public for best presentation! She talked about her research in patients with Hypermobility spectrum disorders and Hypermobility type Ehler Danloss Syndrome. She investigated 3D kinematics and found that patients with instability show less upward rotation and posterior tilting of the scapula compared to healthy subjects without instability. This finding directs us to selecte exercises that elicit more upward rotation and posterior tilting as biomechanically this might benefit shoulder stability during movement.
During the motor learning workshop a lot of interesting ideas were shared by Peter Glashouwer en Norman D’Hondt.
- “Reaching optimal movements needs a surprise party” was quoted to illustrate that we should implement a lot of variation in exercises to achieve motor relearning
- Do not learn your patient to “stabilize” the scapula. This will lead to decreasing degrees of freedom and increased stiffness. Exercise in higher elevation to reinforce scapular upward rotation in shoulder movement.
- Enhance self-reorganisation of the body not by explaining how movement should be performed but by providing new real time sensory input. The “error pattern” should have consequences which make this pattern less attractive for the brain. Another strategy is to organize the body in a way that the new pattern is the only option for the shoulder.
- Reduce the threat by providing a safe environment
- Increase pleasure by providing fun, games and competition
From Ann Cools (@AnnCools4) we were updated on exercise therapy from a clinical laboratory perspective, looking at muscle recruitment and biomechanical variations in exercise prescription. Based upon recent research, the following guidelines may help the clinician in his or her choice for the most appropriate exercises:
The question of the value of kinetic chain training remains unsolved: although it is known that kinetic chain variables change muscle recruitment patterns around the shoulder, especially when implementing diagonal movements, a first study by Dorien Borms (@Dorienborms1) showed that treatment outcome did not differ whether the kinetic chain was involved or not.