Scapulothoracic muscle strength in individuals with neck pain

Abstract

BACKGROUND: People with neck pain often present with weakness in the scapulothoracic muscles. Few studies have examined lower trapezius (LT), middle trapezius (MT) and serratus anterior (SA) muscle strength in individuals with neck pain, nor compared strength to asymptomatic individuals. OBJECTIVES: The aim of this study was to examine LT, MT and SA muscle strength in individuals with chronic neck pain. METHODS: Descriptive cross sectional design. Twenty two individuals with chronic neck pain and 17 asymptomatic individuals were included. Participants were asked to complete a screening questionnaire, Neck Disability Index, and underwent manual muscle testing for the LT, MT, and SA muscles bilaterally. Data analyses included paired and comparative independent t-tests. RESULTS: For individuals with neck pain, significant within subject differences in strength between sides for the LT (P< 0.01) and MT (P< 0.01) were present. In contrast, no within subject difference between sides for the asymptomatic group was found for any muscle. Individuals with neck pain were significantly weaker than asymptomatic individuals for the LT (p= 0.02), MT (p= 0.03), and SA (p= 0.01) on their side of neck pain, but not on their non-painful side. CONCLUSIONS: Significant within subject differences were found between sides for the LT and MT while significant between group differences were identified for all three muscles tested.