Functional tests in women with patellofemoral pain: Which tests make a difference in physical therapy evaluation.

BACKGROUND: Patellofemoral pain (PFP) is characterized by anterior knee, which intensifies during functional activities that require the eccentric action of the quadriceps muscle, specially. In ths way, quantitatively measurable functional tests that simulate these activities should be included in the physical therapy evaluation. OBJECTIVE: To identify which functional tests are most indicated for the evaluation of women with PFD. METHOD: This study evaluated 100 young women (50 with PFP), during the execution of the following functional performance tests: Triple hop, Vertical Jump, Single leg squat, Step Down, YBalance tests, Lunge test and running. Dynamic valgus was also assessed in the tests. The isometric muscle strength of the following muscle groups: hip abductors, extensors and lateral rotators, knee extensors, evertors, and plantar flexors were evaluated. Functional Perception were evaluated by Anterior Knee Pain Scale and Activities of Daily Living Scale. RESULTS: PFP group showed lower performance during the Y-Balance, triple hop, vertical jump tests and running. Was observed an increase in dynamic valgus during Triple Hop, Vertical Jump tests and running in PFP group, besides a poorer perception of function. For all lower limb muscle groups, the PFP group showed a reduction in peak isometric force. CONCLUSION: The YBalance, triple hop, vertical jump tests, and running should be included in the physical therapy evaluation, in addition to aspects of lower limb muscle strength.

Relationship between the strength of the hip and knee stabilizer muscles and the Y balance test performance in adolescent volleyball athletes.

BACKGROUND: Due to the large number of jumping and landing movements, volleyball exerts a high demand on lower limbs, causing a high incidence of injuries. On average, 52% of volleyball injuries occur in lower limbs. Y Balance-test (YBT) is widely used to predict lower limb injury in athletes who jump, so it is important to identify whether the hip and knee stabilizer muscle strength is related to the performance of this test, since muscle strength is important for injury prevention, given the possibility of modifying these factors. The aim of this cross-sectional study was to correlate the strength of the knee and hip stabilizing muscles with YBT in adolescent volleyball athletes. METHODS: A study including 25 young volleyball players (aged 15.3 [0.85] years), was evaluated. The isometric strength of knee extensor muscles, abductors, extensors and lateral hip rotators were assessed by using the manual isometric dynamometer (Lafaytte Instrument Company®, Lafayette, IN, USA). YBT was performed three times on each posterolateral (PL), anterior (ANT) and posteromedial (PM) direction to evaluate the dominant leg. The average of 3 repetitions of isometric strength tests of tested muscles and YBT was analyzed. Pearson's Correlation test was used for the correlation of the variables, considering as strong correlation values (0.5≤r<1), with P≤0.05. RESULTS: A moderate correlation was observed between the knee extensor strength and the ANT direction, and a moderate correlation between the hip extensor strength and the PL direction in YBT. CONCLUSIONS: The strength of knee and hip extensors may be one of the factors that influence the performance of YBT in adolescent volleyball players.

Postural Control During Different Unipodal Positions in Professional Ballet Dancers.

Classical ballet involves the performance of complex movements that require high-level motor skills and good postural control. This study explored postural sway in passé en demi-pointe position in dancers and compared single-leg standing sway (with and without visual restriction) between dancers and non-dancers. Fourteen professional dancers and 14 sex- and age-matched volunteers who were not ballet dancers participated in the study. Participants stood on a force plate on the dominant leg in the following positions: 1. single-leg stance with eyes open (reference task) and with eyes closed and blindfolded for 35 seconds; and 2. passé en demi-pointe position with eyes open for 20 seconds (dancers only). The center of pressure signal was used to calculate the following variables: average velocity; anteroposterior and mediolateral velocity peaks; anteroposterior and mediolateral displacement ranges; average displacement; and ellipse area. Significant interaction effects (p < 0.001, η2 = 0.419) were observed between groups and postural tasks, with higher stabilometric values for the dancer group during the single-leg stance with eyes closed and blindfolded task, as evidenced by the average displacement of 241.0 cm in dancers and 147.1 cm in non-dancers (p = 0.025), and by the ellipse area of 9.5 cm2 for dancers and 4.9 cm2 for non-dancers (p = 0.001). In regard to the positions with eyes open, an increase was noted only in the average sway velocity and mediolateral velocity in passé en demi-pointe position compared with the single-leg stance with eyes open (p < 0.001). Greater postural sway might be interpreted as the result of either inadequate postural stability or exploratory behavior to maintain postural stability in more challenging tasks. It is concluded that professional ballet dancers show greater visual dependency for balance adjustment with reduced influence of the supporting base on postural sway.