Pedro Olavo de Paula Lima

Concurrent validity of the pressure biofeedback unit and surface electromyography in measuring transversus abdominis muscle activity in patients with chronic nonspecific low back pain

BACKGROUND The Pressure biofeedback unit (PBU) is an assessment tool used in clinical practice and research aimed to indirectly analyze the transversus abdominis (TrA) muscle activity. The concurrent validity of the PBU in a clinically relevant sample is still unclear. OBJECTIVE The purpose of this study was to evaluate the concurrent validity and diagnostic accuracy of the PBU in measuring TrA muscle activity in patients with chronic nonspecific low back pain. METHOD This study was performed using a validation, cross-sectional design. Fifty patients with chronic nonspecific low back pain were recruited for this study. To test the concurrent validity both PBU measures (index test) and superficial electromyographic measures (reference-standard test) were compared and collected by a physical therapist in a series of voluntary contraction maneuvers of TrA muscle. RESULTS Participants were on average 22 years old, weighed 63.7 kilos, 1.70 meters height and mean low back pain duration was 1.9 years. It was observed a weak and non-significant Phi coefficient (r=0.2, p<0.20). With regards to diagnostic accuracy tests, our results suggest a low sensitivity (60%) and specificity (60%) of the PBU. The positive predictive value was high (0.8) and negative predictive value was low (0.2). CONCLUSIONS Concurrent validity of the PBU in measuring TrA muscle activity in patients with chronic nonspecific low back pain is poor given the low correlation and diagnostic accuracy with superficial EMG.

The association of ankle dorsiflexion and dynamic knee valgus: A systematic review and meta-analysis

OBJECTIVE The objective of this systematic review was to evaluate the association between ankle dorsiflexion (ADF) and dynamic knee valgus (DKV). METHODS Electronic searches were conducted in MEDLINE, EMBASE, CINAHL and SPORTDiscus. A modified Downs and Black checklist was used for quality assessment and meta-analysis was performed to compare standardised mean differences (SMD) of ADF. RESULTS Seventeen studies met the inclusion criteria. Meta-analysis showed that reduced ADF is associated with participants presenting with DKV compared to controls (SMD -0.65, 95% CI -0.88 to -0.41). Subgroup analysis showed consistent results regarding different forms of ADF measurement; restriction in ADF measured in weight-bearing position (SMD -1.25, 95% CI -2.24 to -0.25), non-weight-bearing with knee flexed (SMD -0.56, 95% CI -0.97 to -0.16) or non-weight-bearing with knee extended (SMD -0.54, 95% CI -0.80 to -0.28) was significantly associated with DKV. CONCLUSION The meta-analysis results provide evidence that reduced ADF is correlated with DKV. The assessment of ADF in the clinical setting is important, as it may be related to harmful movement patterns of the lower limbs.

Translation, cross-adaptation and measurement properties of the Brazilian version of the ACL-RSI Scale and ACL-QoL Questionnaire in patients with anterior cruciate ligament reconstruction

Highlights • The Brazilian versions of ACL-RSI and ACL-QoL were translated and culturally adapted.• The Brazilian ACL-RSI and ACL-QoL demonstrated adequate measurement properties.• The Brazilian ACL-RSI and ACLQoL are useful outcomes for clinical and research.

Y balance test has no correlation with the Stability Index of the Biodex Balance System

STUDY DESIGN A cross-sectional study design. BACKGROUND The Stability Index of the Biodex Balance System (SI-BBS) and Y Balance Test (YBT) has been used in studies assessing postural stability but no studies have verified the association of the YBT with the SI-BBS. OBJECTIVE To analyze the association of the Y Balance Test (YBT) with the Stability Index of the Biodex Balance System (SI-BBS) to evaluate postural stability. METHODS Forty participants who engaged in recreational physical activities, 12 of whom had a history of injury to the lower limbs. Was used the SI-BBS and the anterior, posterolateral, posteromedial, and composite measures of the YBT. The order of execution of the tests and of the lower limbs evaluated was randomized and blind tested by two evaluators. RESULTS Pearsons correlation coefficient was used to check the strength of the relationship between the distances achieved on the YBT and the SI-BBS. The YBT showed excellent reliability in the anterior, posteromedial, and posterolateral directions. However, the YBT showed no statistically significant correlation with any variables in the SI-BBS, indicating poor validity between YBT and SI-BBS assessments of postural stability in people with and without history of lower limb injuries. CONCLUSIONS The results of this study showed the YBT is not correlated with the SI-BBS as an assessment of postural stability. This finding has implications for researchers and clinicians using YBT results as the only measure of postural stability.

Effects of holographic bracelet on balance and muscle performance in soccer players: A quintuple-blind, placebo-controlled, crossover randomized clinical trial

This study aimed to analyze the influence of holographic bracelets on body balance and peak torque in soccer athletes through a quintuple-blind, placebo-controlled, crossover randomized trial. Twenty-eight male athletes were evaluated in a sta- bilometric baropodometer (DIASU ) and performed a protocol involving concentric contractions of the knee at 60 ◦ /s. Athletes were evaluated in three situations: no bracelet (baseline), with a placebo bracelet (PB) and holographic bracelet (HB). Comparing the mean torque peak at 60 ◦ /s during knee extension, there was no statistical difference for the dominant limb (p = 0.713) and non-dominant (p = 0.996) between the baseline, PB and HB groups. No statistical difference was found comparing the mean oscillation ellipses from the right foot with eyes open (p = 0.359) and with eyes closed (p = 0.173), as well as from the left foot with eyes open (p = 0.891) and with eyes closed (p = 0.778). In conclusion, holographic bracelet has no influence on either body balance or knee muscle performance in athletes.

Reliability and Validity of the Hip Stability Isometric Test (HipSIT): A New Method to Assess Hip Posterolateral Muscle Strength

STUDY DESIGN: Cross‐sectional study. BACKGROUND: The Hip Stability Isometric Test (HipSIT) evaluates the strength of the hip posterolateral stabilizers in a position that favors greater activation of the gluteus maximus and gluteus medius and lower activation of the tensor fascia lata. OBJECTIVES: To check the validity and reliability of the HipSIT and to evaluate the HipSIT in women with patellofemoral pain (PFP). METHODS: The HipSIT was evaluated with a handheld dynamometer. During testing, the participants were sidelying, with their legs positioned at 45° of hip flexion and 90° of knee flexion. Participants were instructed to raise the knee of the upper leg while keeping the upper and lower heels in contact. To establish reliability and validity, 49 women were tested with the HipSIT by 2 different evaluators on day 1, and then again 7 days later. The strength of the hip extensors, abductors, and external rotators was also evaluated. Twenty women with unilateral PFP were also evaluated. RESULTS: The HipSIT has excellent intrarater and interrater reliability. The standard error of measurement was 0.01 kgf/kg, and the minimal detectable change was 0.036 kgf/kg. The HipSIT showed good validity in isolated hip abduction, external rotation, and extension (P<.01). Women with PFP showed a 10% deficit in the HipSIT results for the symptomatic limb (P = .01). CONCLUSION: The HipSIT showed excellent interrater and intrarater reliability, moderate to good validity in women, and was able to identify strength deficits in women with PFP.

Index of fatigue quadriceps in soccer athletes after anterior cruciate ligament reconstruction

Objective The present study aimed to evaluate the muscle fatigue of the quadriceps muscle in high-performance soccer players undergoing (anterior cruciate ligament) ACL reconstruction. Methods We evaluated 17 high-performance soccer players from three professional soccer teams of a state in Brazil from August 2011 to July 2012. All subjects were evaluated between 5.5 and 7 months after ACL reconstruction with a Biodex® isokinetic dynamometer (System 4 Pro) with test protocol CON/CON at 60°/s and 300°/s with 5 and 15 repetitions, respectively. In the calculation of local muscle fatigue, the fatigue index was used, which is calculated by dividing the labor done in the first one-third of the repetitions by that done at the final one-third of the repetitions, and multiplying by 100 to express a unit in percentage (i.e., as a discrete quantitative variable). Results All subjects were male, with a mean age of 21.3 ± 4.4 years and mean BMI 23.4 ± 1.53 cm; left dominance was observed in 47% (n = 8) of athletes, and right dominance, in 53% (n = 9) of athletes; and the limb involved in the lesion was the dominant in 29% (n = 5) and the non-dominant in 71% (n = 12). Fatigue rates were 19.6% in the involved limb and 29.0% in the non-involved limb. Conclusion The results allow us to conclude that there was no significant difference between the limbs involved and not in ACL injuries regarding local muscle fatigue. No association was observed between the dominant side and the limb involved in the ACL injury.