Maybe scoliosis is in your head. Katharina Schroth, founder of Schroth therapy for scoliosis wrote “with all scoliotic people the cause probably lies partly in the mental realm” (Schroth, 2007). Recent research studies may confirm her belief. These studies showed that neural activity in the motor association, motor cortex, and the frontal lobe areas of the brain in subjects with idiopathic scoliosis was different than in subjects without idiopathic scoliosis. (Boček et al., 2020; Dominech et al., 2010; Dominech et al., 2011; Gieysztor, Sadowska, Choińska, & Paprocka-Borowicz, 2018).
The motor association area (SMA) receives sensory input relayed by receptors in moving and postural parts of the body via the sensory cortex and input from the basal ganglia regarding postural and movement control. The SMA then compares this information to past experiences, processes it, and relays it to the motor cortex (Chu & Black, 2012; Kaas & Stepniewska, 2002; Domenech et al., 2011). The motor cortex feeds forward the processed information to the muscles and joints in order to direct posture and movement (Chu & Black; Kaas & Stepniewska; Domenech et al).
The involvement of the SMA in brains of people with idiopathic scoliosis (IS) was researched by Doménech et al. (2011). Doménech et al. (2011) used functional MRI’s (fMRI) to measure cerebral cortex oxygen uptake (BOLD) while subjects with and without IS clenched either their right or their left fists. Doménech et al. (2011) found more BOLD, demonstrating more neural activity, in the part of the SMA opposite the clenched fists in the IS group than in the control group (the group without scoliosis). There was also a greater disparity in BOLD between fist clenching with dominant and non- dominant hands of the IS group than the control group. (Doménech et al., 2011). Doménech et al. (2011) wrote that this was a similar pattern to patients with dystonia, that 39 percent of adult patients with cervical dystonia also have scoliosis, and that adults and children with idiopathic cervical dystonia have higher incidences of scoliosis than the general population. According to the NIH, National Institute of Neurological Orders and Stroke (2020) “Dystonia is a disorder characterized by involuntary muscle contractions that cause slow repetitive movements or abnormal postures.” Doménech et al. (2011) concluded that this nonsymmetrical SMA activity may facilitate movement asymmetries that then cause scoliosis.
Several studies have demonstrated increased muscle activity on the convex sides and inhibited muscle activity on the concave sides of scoliotic curves (Avikainen, Rezasoltani, & Kauhanen,1999; Cheung et al., 2005; Kwok, Yip, Cheung & Yip, 2015; Shimada, 1989). Avikainen, Rezasoltani, & Kauhanen,1999; Cheung et al., 2005; Kwok, Yip, Cheung & Yip, 2015; Shimada, 1989). Doménech, Tormos, Barrios, and Pascual-Leone (2010) did research that demonstrated that this muscle imbalance may originate in the motor cortex. The motor cortex is the part of the brain primarily reasonable for motor planning and execution (Dingman, 2015). Doménech et al. (2010) measured the electrical activity of bilateral extensor pollicis longus (thumb extensor) muscles following inhibitory electrical stimulations to the corresponding area in the motor cortex.
They discovered that the left hemisphere of the motor cortex was inhibited less than the right hemisphere in IS subjects but not in subjects with congenital scoliosis or no scoliosis (Doménech et al. 2010). Doménech et al. (2010) noted that the left hemispheric motor pathways cross to the right side of the body and that the subjects with IS had large right thoracic curves.
Primitive reflexes are involuntary movements in response to stimuli that help infants to survive. (Gieysztor, Sadowska, Choińska, & Paprocka-Borowicz, 2018; Modrell & Tadi, 2020; Schott & Rossor, 2003). The cerebral frontal lobe usually inhibits these after infants become 4 to 6 months old (Modrell &Tati). The frontal lobe includes the motor cortex and is responsible for complex cognitive activities such as controlling emotions, solving problems, and motor and cognitive planning (Queensland Brain Institute, 2020). Gieysztor et al. (2018) measured spinal rotation (ATR) with scoliometers and tested primitive reflexes in a group of 61 healthy 5 to 9-year-old children. Unilateral spinal rotation often occurs in scoliosis. Gieysztor et al. found a positive correlation to children whose Galant reflex persisted and positive scoliometer readings. A Galant reflex is the side bending of the spine after the paraspinal muscles on the same side of the spine are stroked (Gieysztor, et al.) This study illustrated that the frontal lobe dysfunction of not inhibiting a Galant reflex could have resulted in scoliosis
These studies implicated SMA, motor cortex, and frontal lobes in the development or facilitation of scoliosis. They were not definitive. Doménech et al. (2011) only used 20 subjects including controls. Doménech et al. (2010) only used 22. None of the studies demonstrated a direct link between brain structures and scoliosis. They all, however, demonstrated that dysfunctions in brain activity correlate with scoliosis. Schroth therapy uses manual facilitative techniques to facilitate inhibited muscles and relax overly tense muscles. It employs purposeful exercises and postures designed to regain postural symmetry. These techniques provide sensory input to the SMA and the motor cortex that may result in the restoration of their normal activity. In addition, Schroth students are trained to consciously change their habitual static and active postures that facilitate scoliosis to ones that decrease scoliosis. This revised body image visualization of symmetrical postures engages the frontal cortex and may normalize its control over primitive reflexes and other sensory motor inputs.
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