Context: The active-knee-extension test (AKE) and the straight-leg-raise test (SLR) are widely used for flexibility assessment. A number of investigations have tested the reliability of these measures, especially the AKE. However, in most studies, the sample involved subjects with normal flexibility. In addition, few studies have determined the standard error of measurement (SEM) and minimal detectable difference (MDD), which can provide complementary and more clinically relevant information than the intraclass correlation coefficient (ICC) alone. Objectives: This study aimed to determine the AKE and LSR intrarater (test-retest) reliability in subjects with flexibility deficits, as well as the correlation between the 2 tests. Design: Reliability study. Setting: Academic laboratory. Subjects: 102 recreationally active participants (48 male, 54 female) with no injury to the lower limbs and with flexibility deficits in the hamstrings muscle group. Main Outcomes: Intrarater reliability was determined using the ICC, complemented by the SEM and MDD. Measures: All participants performed, in each lower limb, 2 trials of the AKE and the SLR. Results: The ICC values found for AKE and SLR tests were, respectively, .87-.94 and .93-.97. The values for SEM were low for both tests (2.6-2.9° for AKE, 2.2-2.6° for SLR), as well as the calculated MDD (7-8° for AKE, 6-7° for SLR). A moderate to strong, and significant, correlation between AKE and SLR was determined for the dominant limb (r = .71) and the nondominant limb (r = .67). Conclusions: These findings suggest that both AKE and SLR have excellent intrarater reliability. The SEMs and MDDs recorded are also very encouraging for the use of these tests in subjects with flexibility deficits.
Tiago Neto, Lia Jacobsohn, Ana I. Carita and Raul Oliveira
Guilherme Assuncao Ferreira, Raul Osiecki, Adriano Eduardo Lima-Silva, Michel Cardoso de Angelis-Pereira and Fernando Roberto De-Oliveira
The objective of this study was to evaluate the effect of a reduced-carbohydrate (reduced-CHO) diet on the rate of perceived exertion (RPE) curve during an incremental test. Nine physically active men performed a progressive incremental test on a cycle ergometer (25 W·2 min−1) after 72 hr on either a control diet (60% CHO) or a reduced-CHO diet (30% CHO). Lactate and RPE thresholds were identified using the Dmax method (DmaxLa and DmaxRPE, respectively). Power output, heart rate and RPE scores in DmaxLa and DmaxRPE were similar between the diets and were not different from each other, regardless of the diet. Lactate values were consistently higher (p < .05) in the control diet compared with the reduced-CHO diet during power output after the lactate breakpoint; however, they were not accompanied by a proportional increase in RPE scores. These results suggest that DmaxRPE and DmaxLa are not dissociated after a short-period reduced-CHO diet, whereas the lactate values after the lactate threshold are reduced with a reduced-CHO diet, although they are not accompanied by alterations in RPE.