Intra and interrater reliability for lower limb flexibility assessment using photogrammetry.

INTRODUCTION: Photogrammetry represents an advancement in the flexibility evaluation, and although it was highly explored for postural assessment, there is a scarcity of studies analyzing lower limb angular measurements using it. The purpose of this study is to verify the reliability of intrarater and interrarater photogrammetry in assessing lower limb flexibility. METHODS: This was a randomized cross-sectional observational study with test-retest design and a two-day interval. Thirty healthy, physically active adults were included. Three novice raters assessed the participants through flexibility tests of iliopsoas, hamstring, quadriceps and gastrocnemius on two occasions, and independently analyzed the captured images to establish reliability. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC) were calculated. RESULTS: Intrarater reliability was excellent for iliopsoas (ICC = 0.96; SEM = 1.4; MDC = 3.8), hamstring (ICC = 0.99; SEM = 1.1; MDC = 3.1), quadriceps (ICC = 0.99; SEM = 0.8; MDC = 2.3) and gastrocnemius (ICC = 0.98; SEM = 0.9; MDC = 2.5). Interrater reliability was excellent for iliopsoas (ICC = 0.94; SEM = 1.7; MDC = 4.6) and gastrocnemius (ICC = 0.91; SEM = 2.1; MDC = 5.8), but good for hamstring (ICC = 0.90; SEM = 2.8; MDC = 7.9) and quadriceps (ICC = 0.85; SEM = 3.0; MDC = 8.3). CONCLUSIONS: The excellent intrarater and good to excellent interrater reliability suggest that photogrammetry assessment of lower limb flexibility by novice raters is reliable. However, clinicians should consider the higher threshold of range of motion change necessary to outweigh measurement error due to interrater variability.

Does static stretching change uniformly the quadriceps elasticity in physically actives subjects?

PURPOSE: Verify the acute responses of static stretching (SS) on the rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) elasticity and knee/hip range of motion (ROM). Additionally, to investigate if there are consistency among quadriceps muscle elasticity after SS. METHODS: Acute effect of SS on pre-post-intervention design. Thirtheen healthy participants (both genders) proposed for a pre-post experimental design. RF, VM, and VL elasticity (strain ratio, SR) was evaluated bilaterally by ultrasound with quasi-static elastography. Higher SR values refer to more rigid tissues. A SS protocol of 3 series of 30 s was applied at right lower limb. The left lower limb was considered as control group. Also, photogrammetry evaluated the knee/hip ROM. RESULTS: For SR muscle comparisons, VM was lower (less stiff) than VL and RF at pre- and post-SS. For time comparisons, no differences were observed for SR and ROM at pre- and post-SS. However, the effect size of the quadriceps SR at SS lower limb was higher than control. CONCLUSION: Acute effects of SS did not change the quadriceps SR or knee/hip ROM in healthy and active subjects. Non-uniform quadriceps SR are observed (VM < VL and RF) independently of SS. Future studies should consider different protocols, muscles, and populations.