Core muscles thickness is not associated with knee frontal plane projection angle during single-leg squat in healthy people.
BACKGROUND
Core muscles play an important role in lower limb stability and alignment, with their weakness being associated with poor alignment and, consequently, with injuries. Despite muscle structure being critical to muscle strength production, we did not find studies associating the morphology of the core muscles and lower limb alignment during functional tasks.


RESEARCH QUESTION
Is there association between thickness of core muscles (external oblique - EO, internal oblique - IO, transversus abdominis - TrA and gluteus medius - GMed) and lower limb alignment during the single-leg squat in healthy subjects?


METHODS
Forty-six healthy participants (27 male and 19 female) performed the following evaluations: (i) measurements of muscle thickness of the EO, IO, TrA and GMed using ultrasound and (ii) measurements of lower limb alignment using the knee frontal plane projection angle (FPPA) during the single-leg squat. A Spearman rank correlation coefficient (rs) was performed between the thickness of selected core muscles (OE, OI, TrA and GMed) and the knee FPPA. In addition, a partial correlation (r) was performed, using sex, physical activity level and body mass index as control variables.


RESULTS
We did not observe significant correlations between the knee FPPA and the thickness of the EO (rs = 0.194; p = 0.197), IO (rs = 0.182; p = 0.225), TrA (rs = 0.073; p = 0.627) and GMed (rs = -0.092; p = 0.542). When controlling for sex, physical activity level and body mass index, similar results were observed [EO (r = 0.157; p = 0.316), IO (r = 0.261; p = 0.092), TrA (r = 0.030; p = 0.850) and GMed (r = -0.144; p = 0.356)] SIGNIFICANCE: Our results demonstrated that core muscles' thickness is not associated with lower limb alignment during the single-leg squat in healthy people.
['Fitarelli|Luan|L|', 'Ramos|Giovana|G|', 'Scudiero|Felipe|F|', 'Rabello|Rodrigo|R|', 'Rodrigues|Rodrigo|R|']
D000009:Abdominal Muscles D000328:Adult D002081:Buttocks D003430:Cross-Sectional Studies D015444:Exercise D005260:Female D006801:Humans D007717:Knee D007719:Knee Joint D008297:Male D053580:Muscle Strength D018482:Muscle, Skeletal D000077708:Sitting Position D013848:Thigh D014463:Ultrasonography D055815:Young Adult
Core Muscle thickness Lower limb alignment Kinematics