Differential Strength and Endurance Parameters of the Craniocervical and Cervicothoracic Extensors and Flexors in Healthy Individuals.
This study examined isometric strength (maximal voluntary contraction [MVC]) and endurance of cervical flexor and extensor muscles in healthy individuals at the craniocervical (CC) and cervicothoracic (CT) axes. MVC and endurance measures (time to task failure in seconds [s]) at 50% MVC were recorded in 4 directions (CC flexion, CC extension, CT flexion, and CT extension) in 20 males and 20 females, and 6 strength and endurance ratios were calculated. The findings showed that the cervical extensor muscles are not only much stronger than the flexors (1.3-2 times greater MVC), but also have greater capacity for endurance (2-2.4 times greater). While males produced significantly greater MVC recordings than females (P < .003), strength ratios (P > .06) and endurance measures (P > .11) were similar. Endurance ratios were also similar except the CT extension to CC flexion ratio, which was significantly larger in females compared with males (P = .03). These findings demonstrate that substantial but normal variation exists in strength and endurance parameters between cervical flexor and extensor muscles. This is informative to clinicians when evaluating the performance of these neck muscles or when deciding on exercise parameters (eg, load, duration) when training their performance.
1 University of Queensland.|2 Royal Brisbane and Womens Hospital.
Shaun
S
O'Leary
1 University of Queensland.|3 Røa Physiotherapy and Rehabilitation.
Charlotte Loraas
CL
Fagermoen
1 University of Queensland.|4 Hope Island Physiotherapy.
Hiroyuki
H
Hasegawa
1 University of Queensland.|5 Centrum Physiotherapy.
Ann-Sofi Slettevold
AS
Thorsen
1 University of Queensland.
Luke
L
Van Wyk
D000328:Adult; D064131:Back Muscles / Q000502:physiology*; D002574:Cervical Vertebrae / Q000502:physiology; D005260:Female; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D009334:Neck Muscles / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013904:Thoracic Vertebrae / Q000502:physiology
cervical spine; dynamometry; muscle performance; ratios