Investigation of the effects of cervical stabilization exercises applied in addition to manual therapy on sensorimotor function and ultrasonographic features of cervical muscles compared to manual therapy alone in individuals with chronic neck pain

The study was aimed to compare the effects of cervical stabilization exercises (CSE) applied in addition to manual therapy (MT) on sensorimotor function, ultrasonographic features of the cervical muscles, and neck pain severity compared to manual therapy alone in individuals with chronic neck pain (CNP). Participants were randomly allocated into MT and MT+Ex (Exercise) groups. MT group was applied MT, whereas the MT+Ex group was applied MT plus CSE. Postural stability test (PST), limits of stability test, and modify sensory organization test (MSOT)) with posturography, head reposition (HR) and target angle (TA) tests with an inclinometer, cross-sectional areas (CSA) of longus colli (LC) and multifidus (MtF) muscles and stiffness of sternocleidomastoid (SCM), levator scapulae (LS), and upper part of trapezius (TRP) muscles with ultrasonography method, and pain severity with Visual Analog Scale (VAS) were assessed. After treatment, a decrease in double leg [p=0.006; r (effect size)=0.674] and non-dominant single leg (p=0.034; r=0.576) PST sway index, HR error (p<0.001; r=0.906) and LS (p<0.001; r=0.933) and TRP (p=0.025; r=0.598) muscle stiffness and an increase in the CSA of LC (p=0.002; r=0.725) and Mtf (p<0.001; r=0.897) were found only in the MT+Ex group. Eyes open-soft surface MSOT sway index, 300 flexion TA error, SCM muscle stiffness and VAS score were decreased both MT (p=0.008; r=0.661, p<0.001; r= 0.796, p<0.001; r=0.775, p<0.001; r=0.918) and in the MT+Ex groups (p=0.037; r=0.570, p=0.027; r=0.592, p=0.001; r=0.738, p<0.001; r=0.884). The decrease in HR error and LS muscle stiffness and increase in CSA of Mtf were greater in the MT+Ex group compared to the MT group (p=0.002, p<0.001, p<0.001). CSE in addition to MT may be more effective than MT alone in improving sensorimotor function, decreasing superficial cervical muscle stiffness, and increasing the CSA of deep cervical muscles. Keywords: Neck pain, neck muscles, exercise, musculoskeletal manipulations, postural balance, proprioception