The effect of craniocervical flexors endurance training on suprahyoid muscle activation in healthy adults: A randomised controlled trial

Background Cervical posture affects swallowing function through contractile and non-contractile structures. Craniocervical flexor endurance training (CCFET), which focuses on the activation of deep cervical muscles, is used to ensure cervical posture stability. Objective The aim of this study was to investigate the effect of CCFET on the suprahyoid muscles (SH), which play an important role in swallowing function. Methods Eighty healthy individuals (52 female and 28 male, mean age 21.77 +/- 1.81 years) were recruited and randomly assigned to groups that underwent either deep cervical flexor (DCF) training with a pressure biofeedback unit (CCFET group, n = 41) or no intervention (control group, n = 39). The intervention was applied for 4 weeks (five sessions per week). Static endurance and activation of DCF muscles (Craniocervical Flexion Test, CCFT), tragus-wall distance (TWD) for forward head posture and surface electromyographic (sEMG) activation of suprahyoid muscles were evaluated. Results The endurance and activation of the DCF muscles were significantly increased in the CCFET group (p = <.001). In the CCFET group, TWD significantly lower than the control group (p = <.001) Peak SH amplitude and mean SH amplitude were lower in the CCFET group compared to the control group (p = .013, p = .003). Conclusion The study shows that 4 weeks of CCFET reduced SH muscle activation, allowing the same work to be done with fewer motor units. CCFET can be included in rehabilitation programs as an additional method that has an effect on the muscles involved in swallowing by providing cervical motor control.