Correlations between Cervical Lordosis, Forward Head Posture, Cervical ROM and the Strength and Endurance of the Deep Neck Flexor Muscles in College Students

[Purpose] This study was conducted in order to examine the correlations between cervical lordosis angles (Absolute Rotation Angle, ARA, forward head posture, FHP, Anterior Weight Bearing, AWB), the range of flexion and extension (RFEM), the strength and endurance of the deep neck flexor (DNF) and cervical pain. [Subjects] The study enrolled 24 university students (female: 12, male:12) aged in their 20s. [Methods] ARA, AWB and RFEM were analyzed using radiographs of lateral views. Strength and endurance were assessed using a Pressure Biofeedback Unit (PBU) and cervical pain and physical functions were assessed using the Neck Disability Index (NDI).[Results]As ARA increased, extension and RFEM also increased, and as AWB decreased, extension and endurance increased. As extension increased, RFEM and endurance increased and NDI decreased. As flexion became larger, RFEM and NDI increased, and as RFEM increased, endurance increased. [Conclusion] The study results indicate that the posture of the cervical spine affects the endurance rather than the strength of the DNF. Therefore, as therapeutic interventions to enhance the endurance of the DNF, posture control to reduce AWB and approaches to increase extension and RFEM should be considered.