What's in your toolbox as a fallback when your go to assessments and treatments aren't having an effect? Some things I start to examine are lifestyle, nutrition, sleep, and stress. Sometimes it's as simple as an activity they haven't told you about or a position they adopt frequently that are negating the treatment effects.
However, after taking those into account, or if they have conditions like chronic fatigue, POTS, chronic pain, or MSK complaints that aren't improving, I assess for overbreathing.
I made a handy guide that explains the basics. I'm developing a course on it as overbreathing assessment and treatments should be in every PT's toolbox.
An Guide for Physical Therapists
A muscle contraction where the muscle generates force without changing its length (i.e., no joint movement).
Mechanism: Isometric contractions, especially high-intensity ones (70% MVC or greater), activate brain regions involved in pain processing (e.g., periaqueductal gray, rostral ventromedial medulla).
Effect: This leads to the release of endogenous opioids (e.g., endorphins, enkephalins) and other neurotransmitters that inhibit pain signals from reaching the brain. This is often referred to as Conditioned Pain Modulation (CPM).
Why it helps: Provides immediate, short-term analgesia, creating a "window of opportunity" for movement or further therapeutic exercise.
Mechanism: Non-noxious input (like the strong sensory feedback from a sustained isometric contraction) travels via large-diameter Aβ fibers.
Effect: This input can "close the gate" in the spinal cord, blocking or reducing the transmission of noxious pain signals (carried by smaller C and Aδ fibers) to the brain.
Why it helps: Reduces the perception of pain at the spinal cord level.
Mechanism: Pain often leads to protective muscle guarding or spasm. Isometric contractions can help to gently engage and then relax these muscles.
Effect: By activating muscles without movement, it can help to break the pain-spasm-pain cycle, improve local circulation, and reduce sensitivity.
Why it helps: Addresses a common contributor to musculoskeletal pain, allowing for better tissue healing and movement.
Mechanism: Sustained isometric holds provide rich proprioceptive feedback to the CNS about joint position and muscle tension.
Effect: Enhances the body's internal map and awareness of the affected area, which can be disrupted in chronic pain states.
Why it helps: Better body awareness can reduce fear of movement and improve motor control, contributing to pain reduction.
Mechanism: Successfully performing an isometric contraction, even in the presence of pain, can increase self-efficacy and reduce kinesiophobia (fear of movement).
Effect: Patients gain confidence that they can move and load the affected area without exacerbating pain.
Why it helps: Addresses the emotional and cognitive components of pain, empowering patients in their recovery.
Isometric contractions offer a versatile, low-risk, and effective strategy for pain modulation across various musculoskeletal conditions. By leveraging both central and peripheral mechanisms, alongside psychological benefits, they provide physical therapists with an immediate and empowering intervention for their patients.