Rodrigo de Marche Baldon

The effect of additional strengthening of hip abductor and lateral rotator muscles in patellofemoral pain syndrome: a randomized controlled pilot study

Objectives: To study the effect of additional strengthening of hip abductor and lateral rotator muscles in a strengthening quadriceps exercise rehabilitation programme for patients with the patellofemoral pain syndrome. Design: Randomized controlled pilot trial. Setting: Clinical setting with home programme. Participants: Fourteen patients with patellofemoral pain syndrome. Intervention: The subjects were randomly assigned to the intervention group (strengthening of quadriceps plus strengthening of hip abductor and lateral rotator muscles) or to the control group (strengthening of quadriceps). Both groups participated in a six-week home exercise protocol. Main outcome measures: The perceived pain symptoms, isokinetic eccentric knee extensor, hip abductor and lateral rotator torques and the gluteus medius electromyographic activity were assessed before and after treatment. Parametric and non-parametric tests were used to compare the groups before and after treatment with α=0.05. Results: Only the intervention group improved perceived pain symptoms during functional activities (P=0.02—0.04) and also increased their gluteus medius electromyographic activity during isometric voluntary contraction (P=0.03). Eccentric knee extensors torque increased in both groups (P=0.04 and P=0.02). There was no statistically significant difference in the hip muscles torque in either group. Conclusion: Supplementation of strengthening of hip abductor and lateral rotator muscles in a strengthening quadriceps exercise programme provided additional benefits with respect to the perceived pain symptoms during functional activities in patients with patellofemoral pain syndrome after six weeks of treatment.

Eccentric Hip Muscle Function in Females With and Without Patellofemoral Pain Syndrome

CONTEXT Patellofemoral pain syndrome (PFPS) is a common knee condition in athletes. Recently, researchers have indicated that factors proximal to the knee, including hip muscle weakness and motor control impairment, contribute to the development of PFPS. However, no investigators have evaluated eccentric hip muscle function in people with PFPS. OBJECTIVE To compare the eccentric hip muscle function between females with PFPS and a female control group. DESIGN Cross-sectional study. SETTING Musculoskeletal laboratory. PATIENTS OR OTHER PARTICIPANTS two groups of females were studied: a group with PFPS (n = 10) and a group with no history of lower extremity injury or surgery (n = 10). INTERVENTION(S) Eccentric torque of the hip musculature was evaluated on an isokinetic dynamometer. MAIN OUTCOME MEASURE(S) Eccentric hip abduction, adduction, and external and internal rotation peak torque were measured and expressed as a percentage of body mass (Nm/kg x 100). We also evaluated eccentric hip adduction to abduction and internal to external rotation torque ratios. The peak torque value of 5 maximal eccentric contractions was used for calculation. Two-tailed, independent-samples t tests were used to compare torque results between groups. RESULTS Participants with PFPS exhibited much lower eccentric hip abduction (t(18) = -2.917, P = .008) and adduction (t(18) = -2.764, P = .009) peak torque values than did their healthy counterparts. No differences in eccentric hip external (t(18) = 0.45, P = .96) or internal (t(18) = -0.742, P = .47) rotation peak torque values were detected between the groups. The eccentric hip adduction to abduction torque ratio was much higher in the PFPS group than in the control group (t(18) = 2.113, P = .04), but we found no difference in the eccentric hip internal to external rotation torque ratios between the 2 groups (t(18) = -0.932, P = .36). CONCLUSIONS Participants with PFPS demonstrated lower eccentric hip abduction and adduction peak torque and higher eccentric adduction to abduction torque ratios when compared with control participants. Thus, clinicians should consider eccentric hip abduction strengthening exercises when developing rehabilitation programs for females with PFPS.

Effects of Functional Stabilization Training on Pain, Function, and Lower Extremity Biomechanics in Women With Patellofemoral Pain: A Randomized Clinical Trial

STUDY DESIGN Randomized clinical trial. OBJECTIVES To compare the effects of functional stabilization training (FST) versus standard training on knee pain and function, lower-limb and trunk kinematics, trunk muscle endurance, and eccentric hip and knee muscle strength in women with patellofemoral pain. BACKGROUND A combination of hip- and knee-strengthening exercise may be more beneficial than quadriceps strengthening alone to improve pain and function in individuals with patellofemoral pain. However, there is limited evidence of the effectiveness of these exercise programs on the biomechanics of the lower extremity. METHODS Thirty-one women were randomized to either the FST group or standard-training group. Patients attended a baseline assessment session, followed by an 8-week intervention, and were reassessed at the end of the intervention and at 3 months after the intervention. Assessment measures were a 10-cm visual analog scale for pain, the Lower Extremity Functional Scale, and the single-leg triple-hop test. A global rating of change scale was used to measure perceived improvement. Kinematics were assessed during the single-leg squat. Outcome measures also included trunk endurance and eccentric hip and knee muscle strength assessment. RESULTS The patients in the FST group had less pain at the 3-month follow-up and greater global improvement and physical function at the end of the intervention compared to those in the standard-training group. Lesser ipsilateral trunk inclination, pelvis contralateral depression, hip adduction, and knee abduction, along with greater pelvis anteversion and hip flexion movement excursions during the single-leg squat, were only observed in the FST group after the intervention. Only those in the FST group had greater eccentric hip abductor and knee flexor strength, as well as greater endurance of the anterior, posterior, and lateral trunk muscles, after training. CONCLUSION An intervention program consisting of hip muscle strengthening and lower-limb and trunk movement control exercises was more beneficial in improving pain, physical function, kinematics, and muscle strength compared to a program of quadriceps-strengthening exercises alone.

Effect of functional stabilization training on lower limb biomechanics in women.

PURPOSE This study aimed to verify the effects of functional stabilization training on lower limb kinematics, functional performance, and eccentric hip and knee torques. METHODS Twenty-eight women were divided into a training group (TG; n = 14), which carried out the functional stabilization training during 8 wk, and a control group (CG; n = 14), which carried out no physical training. The kinematic assessment of the lower limb was performed during a single-leg squat, and the functional performance was evaluated by way of the single-leg triple hop and the timed 6-m single-leg hop tests. The eccentric hip abductor, adductor, lateral rotator, medial rotator, and the knee flexor and extensor torques were measured using an isokinetic dynamometer. RESULTS After 8 wk, the TG significantly reduced the values for knee abduction (from -6.86° to 1.49°), pelvis depression (from -10.21° to -7.86°) and femur adduction (from 7.08° to 5.19°) as well as increasing the excursion of femur lateral rotation (from -0.55° to -3.67°). Similarly, the TG significantly increased the values of single-leg triple hop (from 3.52 to 3.92 m) and significantly decreased the values of timed 6-m single-leg hop tests (from 2.43 to 2.14 s). Finally, the TG significantly increased the eccentric hip abductor (from 1.31 to 1.45 N · m · kg(-1)), hip lateral rotator (from 0.75 to 0.91 N · m · kg(-1)), hip medial rotator (from 1.45 to 1.66 N · m · kg(-1)), knee flexor (from 1.43 to 1.55 N · m · kg(-1)), and knee extensor (from 3.46 to 4.40 N · m · kg(-1)) torques. CONCLUSIONS Strengthening of the hip abductor and lateral rotator muscles associated with functional training improves dynamic lower limb alignment and increases the strength and functional performance.

Electromyographic preactivation pattern of the gluteus medius during weight-bearing functional tasks in women with and without anterior knee pain

BACKGROUND Proximal factors have been proposed to influence the biomechanics of the patellofemoral joint. A delayed or diminished gluteus medius (GM) activation, before the foot contact on the ground during functional activities could lead to excessive femur adduction and internal rotation and be associated with anterior knee pain (AKP). There are few studies on this topic and the results were inconclusive, therefore, it is necessary to investigate the GM preactivation pattern during functional activities. OBJECTIVE To compare the GM electromyographic (EMG) preactivation pattern during walking, descending stairs and in single leg jump task in women with and without AKP. METHODS Nine women clinically diagnosed with AKP and ten control subjects with no history of knee injury participated in this study. We evaluated GM EMG linear envelope before the foot contact on the ground during walking and GM onset time and EMG linear envelope during descending stairs as well as in a single leg vertical jump. Mann-Whitney U tests were used to determine the between-group differences in GM EMG preactivation pattern. RESULTS No between-group differences were observed in GM linear envelope during walking (P=0.41), GM onset time and linear envelope during descending stairs (P=0.17 and P=0.15) and single leg jump (P=0.81 and P=0.33). CONCLUSIONS Women with AKP did not demonstrated altered GM preactivation pattern during functional weight bearing activities. Our results did not support the hypothesis that poor GM preactivation pattern could be associated with AKP.

Evaluating Eccentric Hip Torque and Trunk Endurance as Mediators of Changes in Lower Limb and Trunk Kinematics in Response to Functional Stabilization Training in Women With Patellofemoral Pain

Background: Altered movement patterns of the trunk and lower limbs have been associated with patellofemoral pain (PFP). It has been assumed that increasing the strength of the hip and trunk muscles would improve lower limb and trunk kinematics in these patients. However, evidence in support of that assumption is limited. Purpose: To determine whether increases in the strength of hip muscles and endurance of trunk muscles in response to functional stabilization training will mediate changes in frontal plane lower limb kinematics in patients with PFP. Study Design: Controlled laboratory study. Methods: Thirty-one female athletes were randomized to either a functional stabilization training group that emphasized strengthening of the trunk and hip muscles or a standard training group that emphasized stretching and quadriceps strengthening. Patients attended a baseline assessment session, followed by 8 weeks of intervention, and were then reassessed at the end of the intervention period. The potential mediators that were evaluated included eccentric torque of hip muscles and endurance of the trunk muscles. The outcome variables were the lower limb and trunk kinematics in the frontal plane assessed during a single-legged squat task. Results: The eccentric strength of the gluteus muscles showed a mediation effect ranging from 18% to 32% on changes to frontal plane kinematics (decreased ipsilateral trunk inclination, pelvis contralateral depression, and hip adduction excursions) observed in the functional stabilization training group after intervention. Conclusion: Although the mediation effects were small, the results suggest that improvements in the strength of the gluteus muscles can influence the frontal plane movement patterns of the lower limb and trunk in women with PFP. Clinical Relevance: Patients with PFP might benefit from strengthening of the hip muscles to improve frontal plane lower limb and trunk kinematics during functional tasks.

Differences between genders in eccentric hip adduction to abduction, hip medial to lateral rotation and knee flexion to extension peak torques ratios

Muscle imbalances appear to contribute to lower limb injuries and the incidence rate of some knee injuries has been reported to be greater in females than in males. The purposes of this study were to compare the differences between genders in eccentric hip and knee peak torques normalized according to body mass as well as in eccentric hip adduction to abduction (HAD/HAB), hip medial to lateral rotation (HMR/HLR) and knee flexion to extension (KF/KE) peak torques ratios. Seventee n males and twenty-two females participated in this study. Eccentric hip and knee peak torque for each movement were measured using an isokinetic dynamometer (Biodex Multi-Joint System 2). The Student t test for independent samples and the Mann- Whitney U test were used for all comparisons between genders (� = 0.05). The results showed that females had significantly lower eccentric hip adduction, abduction, medial rotation and lateral rotation as well as lower knee flexion and extensi on peak torques. Females also showed greater eccentric HAD/HAB and HMR/HLR as well as lower KF/KE peak torques ratios when compared to males. The differences verified between genders help to explain the greater rate of knee disorders observed i n females.

Diferenças biomecânicas entre os gêneros e sua importância nas lesões do joelho

INTRODUCTION: Several studies have been carried out to determine the biomechanical factors responsible by the greater incidence of patellofemoral pain syndrome and anterior cruciate ligament injury in women, when compared to men. OBJECTIVE: The aim of this study was to perform a non-systematic review of the literature of the biomechanical differences between genders, especially those concerning to the hip joint, related to the higher incidence of knee injuries in women, and verify its implications for developing preventive strategies. METHODOLOGY: Articles published between 1985 and 2008 were selected by two independent reviewers of the follow data bases: LILACS, MEDLINE, Cocharane and PubMed. It was selected theoretical, transversal, and correlational studies as well as controlled clinical trial with experimental designs well defined. RESULTS AND DISCUSSION: The studies selected showed that women perform functional activities with lower angles of knee and hip flexion, as well as greater knee valgus, hip adduction and medial rotation. Furthermore, it is believed that the differences shown in the coronal and transverse planes of the hip are more significant for the development of injuries in women than those occurred only in the sagittal plane. Finally, the studies show that neuromuscular training carried out preventively improves the dynamic alignment of the lower limb in women, reducing the incidence of knee injuries on them. CONCLUSION: There are evidences that women have biomechanics differences of the lower limb movement pattern when compared to men that may contribute for the greater incidence of knee injuries observed in women.