Isometric Hip Research Articles

Isometric and isokinetic hip strength and agonist/antagonist ratios in symptomatic femoroacetabular impingement.

This study investigated isometric and isokinetic hip strength in individuals with and without symptomatic femoroacetabular impingement (FAI). The specific aims were to: (i) determine whether differences exist in isometric and isokinetic hip strength measures between groups; (ii) compare hip strength agonist/antagonist ratios between groups; and (iii) examine relationships between hip strength and self-reported measures of either hip pain or function in those with FAI. Cross-sectional. Fifteen individuals (11 males; 25±5 years) with symptomatic FAI (clinical examination and imaging (alpha angle >55° (cam FAI), and lateral centre edge angle >39° and/or positive crossover sign (combined FAI))) and 14 age- and sex-matched disease-free controls (no morphological FAI on magnetic resonance imaging) underwent strength testing. Maximal voluntary isometric contraction strength of hip muscle groups and isokinetic hip internal (IR) and external rotation (ER) strength (20°/s) were measured. Groups were compared with independent t-tests and Mann-Whitney U tests. Participants with FAI had 20% lower isometric abduction strength than controls (p=0.04). There were no significant differences in isometric strength for other muscle groups or peak isokinetic ER or IR strength. The ratio of isometric, but not isokinetic, ER/IR strength was significantly higher in the FAI group (p=0.01). There were no differences in ratios for other muscle groups. Angle of peak IR torque was the only feature correlated with symptoms. Individuals with symptomatic FAI demonstrate isometric hip abductor muscle weakness and strength imbalance in the hip rotators. Strength measurement, including agonist/antagonist ratios, may be relevant for clinical management of FAI.

Neuromuscular Activation of the Vastus Intermedius Muscle during Isometric Hip Flexion.

Although activity of the rectus femoris (RF) differs from that of the other synergists in quadriceps femoris muscle group during physical activities in humans, it has been suggested that the activation pattern of the vastus intermedius (VI) is similar to that of the RF. The purpose of present study was to examine activation of the VI during isometric hip flexion. Ten healthy men performed isometric hip flexion contractions at 25%, 50%, 75%, and 100% of maximal voluntary contraction at hip joint angles of 90°, 110° and 130°. Surface electromyography (EMG) was used to record activity of the four quadriceps femoris muscles and EMG signals were root mean square processed and normalized to EMG amplitude during an isometric knee extension with maximal voluntary contraction. The normalized EMG was significantly higher for the VI than for the vastus medialis during hip flexion at 100% of maximal voluntary contraction at hip joint angles of 110° and 130° (P < 0.05). The onset of VI activation was 230–240 ms later than the onset of RF activation during hip flexion at each hip joint angle, which was significantly later than during knee extension at 100% of maximal voluntary contraction (P < 0.05). These results suggest that the VI is activated later than the RF during hip flexion. Activity of the VI during hip flexion might contribute to stabilize the knee joint as an antagonist and might help to smooth knee joint motion, such as in the transition from hip flexion to knee extension during walking, running and pedaling.

Neuromuscular performance in the hip joint of elderly fallers and non-fallers

Low strength and neuromuscular activation of the lower limbs have been associated with falls making it an important predictor of functional status in the elderly. To compare the rate of neuromuscular activation, rate of torque development, peak torque and reaction time between young and elderly fallers and non-fallers for hip flexion and extension. We evaluated 44 elderly people who were divided into two groups: elderly fallers (n=20) and elderly non-fallers (n=24); and 18 young people. The subjects performed three isometric hip flexion and extension contractions. Electromyography data were collected for the rectus femoris, gluteus maximus and biceps femoris muscles. The elderly had 49% lower peak torque and 68% lower rate of torque development for hip extension, 28% lower rate of neuromuscular activation for gluteus maximus and 38% lower rate of neuromuscular activation for biceps femoris than the young (p<0.05). Furthermore, the elderly had 42% lower peak torque and 62% lower rate of torque development for hip flexion and 48% lower rate of neuromuscular for rectus femoris than the young (p<0.05). The elderly fallers showed consistent trend toward a lower rate of torque development than elderly non-fallers for hip extension at 50ms (29%, p=0.298, d=0.76) and 100ms (26%, p=0.452, d=0.68).The motor time was 30% slower for gluteus maximus, 42% slower for rectus femoris and 50% slower for biceps femoris in the elderly than in the young. Impaired capacity of the elderly, especially fallers, may be explained by neural and morphological aspects of the muscles. The process of senescence affects the muscle function of the hip flexion and extension, and falls may be related to lower rate of torque development and slower motor time of biceps femoris.

Effects of Different Types of Isometric Hip Contraction on Gluteus Medius and Tensor Fasciae Latae Activity During Squat Exercises

Hip muscle activation and strengthening exercise programs are often used to prevent and treat various lower extremity injuries. Common exercise programs include squat exercises. The purposes of this study were to investigate gluteus medius (GMED) and tensor fasciae latae (TFL) muscle activity, and to assess the GMED/TFL ratio during squat exercises involving different isometric hip contraction conditions. Different types of isometric hip contraction were standard squat without hip contraction, squats with isometric hip adduction, and squats with isometric hip abduction. Twenty (10 males and 10 females) healthy subjects (23.7±2.8 years old) were recruited. Subjects performed the squat exercises with the back supported by a wall and knees flexed to 60°. Surface electromyography (EMG) was used to measure GMED and TFL activity. One-way repeated analysis of variance was used to compare GMED and TFL muscle activity and the GMED/TFL ratio. GMED and TFL EMG activity was significantly higher during squats with isometric hip adduction and abduction compared with the standard squat without hip contraction (p<.05). Between the isometric hip adduction and abduction contraction conditions, only the TFL EMG activity was significantly higher during squats with isometric hip adduction than isometric hip abduction (p<.05). The GMED/TFL ratio was significantly higher during squats with isometric hip adduction than isometric hip abduction (p<.05). Squats with isometric hip adduction and abduction improved GMED and TFL muscle activity. Furthermore, the GMED/TFL ratio was higher during isometric hip adduction than isometric hip abduction. Our data indicate that squat exercises involving isometric hip adduction enhance GMED muscle activity.

Frontal plane kinematics of the hip during running: Are they related to hip anatomy and strength?

Excessive hip adduction has been associated with a number of lower extremity overuse running injuries. The excessive motion has been suggested to be the result of reduced strength of the hip abductor musculature. Hip anatomical alignment has been postulated to influence hip abduction (HABD) strength and thus may impact hip adduction during running. The purpose of this study was to investigate the relationship between hip anatomy, HABD strength, and frontal plane kinematics during running. Peak isometric HABD strength, 3D lower extremity kinematics during running, femoral neck-shaft angle (NSA), and pelvis width–femur length (PW–FL) ratio were recorded for 25 female subjects. Pearson correlations (p<0.05) were performed between variables. A fair relationship was observed between femoral NSA and HABD strength (r=−0.47, p=0.02) where an increased NSA was associated with reduced HABD strength. No relationship was observed between HABD strength and hip adduction during running. None of the anatomical measurements, NSA or PW–FL, were associated with hip adduction during running. Deviations in the femoral NSA have a limited ability to influence peak isometric hip abduction strength or frontal plane hip kinematics during running. Hip abduction strength does also not appear to be linked with changes in hip kinematics. These findings in healthy individuals question whether excessive hip adduction typically seen in female runners with overuse injuries is caused by deviations in hip abduction strength or anatomical structure.

Proximal muscle rehabilitation is effective for patellofemoral pain: a systematic review with meta-analysis

BackgroundProximal muscle rehabilitation is commonly prescribed to address muscle strength and function deficits in individuals with patellofemoral pain (PFP). This review (1) evaluates the efficacy of proximal musculature rehabilitation for...

Hip Strength Deficits in Patients With Symptomatic Femoroacetabular Impingement and Labral Tears

To determine the prevalence of hip strength deficits in a consecutive cohort of patients with unilateral femoroacetabular impingement (FAI) compared with the asymptomatic contralateral hip. Fifty consecutive patients undergoing hip arthroscopy for symptomatic FAI underwent preoperative hip strength dynamometer measurements and were included in the study. Manual isometric hip strength measurements were performed with a handheld dynamometer and included measurements of various hip strengths (flexion, extension, adduction, abduction, internal rotation, and external rotation). Weakness greater than or equal to 10% for any given measurement was defined as a strength deficit in this study. Clinical data including age, gender, size of labral tear, and preoperative outcome scores were recorded. Outcome scores included the modified Harris Hip Score and Short Form 12Physical Component. The mean age of patients in the study was 32.0 years (range, 18.1 to 49.8 years). There were 32 male and 18 female patients. Hip abduction strength deficits were seen in 46% of patients and flexion strength deficits in 42% of patients. An 8% decrease in strength of the involved hip was seen in flexion, and an 8.7% decrease was seen in abduction. Patients with hip flexion strength deficits had a loss of function (mean modified Harris Hip Score, 57.8 v 66.1; P= .021) and larger labral tears (mean, 39 mm v 28 mm; P= .003). Hip flexion strength deficits correlated with loss of hip flexion (r= 0.373, P= .008). Hip strength deficits were common in patients presenting with unilateral symptomatic FAI and occurred most commonly in hip abduction and flexion. Strength deficits in hip flexion were associated with decreased function, loss of motion, and larger labral tears in patients with FAI and labral tears. Level IV, prognostic case series.

A randomised trial into the effect of an isolated hip abductor strengthening programme and a functional motor control programme on knee kinematics and hip muscle strength.

BackgroundDynamic knee valgus and internal femoral rotation are proposed to be contributory risk factors for patellofemoral pain and anterior cruciate ligament injuries. Multimodal interventions including hip abductor strengthening or functional motor control programmes have a positive impact of pain, however their effect on knee kinematics and muscle strength is less clear. The aim of this study was to examine the effect of isolated hip abductor strengthening and a functional motor control exercise on knee kinematics and hip abductor strength.MethodsThis prospective, randomised, repeated measures design included 29 asymptomatic volunteers presenting with increase knee valgus and femoral internal rotation. Participants completed either isolated hip abductor strengthening or a functional motor control exercise for 5 weeks. Knee kinematics were measured using inertial sensors during 2 functional activities and hip abductor strength measured using a load cell during isometric hip abduction.ResultsThere were no significant differences in dynamic knee valgus and internal rotation following the isolated hip abductor or functional motor control intervention, and no significant differences between the groups for knee angles. Despite this, the actual magnitude of reduction in valgus was 10° and 5° for the functional motor control group and strengthening group respectively. The actual magnitude of reduction in internal rotation was 9° and 18° for the functional motor control group and strengthening group respectively. Therefore there was a tendency towards clinically significant improvements in knee kinematics in both exercise groups. A statistically significant improvement in hip abductor strength was evident for the functional motor control group (27% increase; p = 0.008) and strengthening group (35% increase; p = 0.009) with no significant difference between the groups being identified (p = 0.475).ConclusionsIsolated hip strengthening and functional motor control exercises resulted in non-statistically significant changes in knee kinematics, however there was a clear trend towards clinically meaningful reductions in valgus and internal rotation. Both groups demonstrated similar significant gains in hip abductor strength suggesting either approach could be used to strengthen the hip abductors.

Relationship between functional performance and falls in female patients with end stage hip osteoarthritis

s / Osteoarthritis and Cartilage 23 (2015) A82eA416 A349 568 RELATIONSHIP BETWEEN FUNCTIONAL PERFORMANCE AND FALLS IN FEMALE PATIENTS WITH END STAGE HIP OSTEOARTHRITIS F. Pozzi y, S. Abujaber z, S. Fenstermacher y, J. Zeni, Jr. y. yUniv. of Delaware, Newark, DE, USA; z The Univ. of Jordan, Amman, Jordan Purpose: To compare functional performance between women with end stage hip osteoarthritis (OA) who sustained a fall within the previous 6 months and women who did not. In addition, the relationship between functional performance and fall status (yes/no) will be explored. Methods: Thirty-one female individuals (age 65±8 years of age, 30.8±7.8Kg/m2 BMI) who were scheduled to undergo total hip arthroplasty were enrolled in this study. Patients underwent a functional evaluation with a physical therapist approximately 2 weeks before the surgery. Self-reported function was assessed using the Hip Harris Score (HHS) and the Hip Outcome Score (HOS). Total hip range of motion (ROM) was calculated as part of the HHS. Pain in the lower extremity joints and low back was measured using an analog scale (0, no pain; 10, worst pain imaginable). Isometric hip abductor strength was measured using a hand held dynamometer and knee extensor strength was measured using an electromechanical dynamometer. Both strength measures were normalized according to body weight. Functional performance was assessed with the Timed Up-and-Go (TUG), Stair climbing (SCT), and Six Minute Walk (6MW) tests. Fall status was assessed by asking patients whether they sustained a fall in the previous 6 months. The group was then divided into fall and no-fall groups based on the response to the fall question. An independent sample ttest was used to compare data between groups. Point-biserial correlation coefficient was then calculated to explore the relationship between functional variables and fall status. The quartile distribution of the performance on the functional tests (TUG, SCT, and 6MW) was built with the data from all subjects. The percentile value of the performance of the subjects in the fall group was then calculated. Results: Seven out of 31 patients (22.5%) reported sustaining at least one fall within 6 months from the evaluation session. Patients that fell were significantly older (þ8 years, p 1⁄4 0.01) and had significantly less total hip ROM (-21 , p 1⁄4 0.03) and quadriceps strength on both surgical and non-surgical side (-0.82 and -0.97 Nm/Kg, respectively, p 1⁄4 0.04). Additionally, patients in the fall group took longer time to complete the TUG (þ6.73s, p < 0.01) and SCT (þ18.76s, p < 0.01), and walk shorter distance in the 6MW test (-134.8m, p < 0.01, table 1). The correlation analysis revealed that older age and worse performance during functional tests were strongly related falls (Table 1). The percentile distribution of the performance during functional tests for subjects in the fall group revealed that most of the patients performed below the 25th percentile for each functional measures, although two subjects in the fall group were in the top quartile for TUG and SCT (Figure 1). Table 1 Demographic characteristics, range of motion, pain, strenght, performance tests, and sel

Isometric hip abduction strength is not related to single-limb mini squat performance in participants with knee and hip pain

Isometric hip abduction strength is not related to single-limb mini squat performance in participants with knee and hip pain

Gait and lower limb muscle strength in women after triple innominate osteotomy

BackgroundIn adult patients with developmental hip dysplasia, a surgical procedure (triple innominate osteotomy) of the pelvic bone can be performed to rotate the acetabulum in the frontal plane, establishing better acetabular coverage. Although common clinical hip scores demonstrate significant improvements after surgery, they provide only overall information about function. The purpose of this study was to quantify the long-term outcome of triple innominate osteotomy in more detail using gait analyses and muscle strength measurements.MethodsWe performed gait analyses at self-selected walking speed as well as isometric hip and knee muscle strength tests in twelve women who had undergone a unilateral triple innominate osteotomy (age: 34 ± 12 y, time post surgery: 80 ± 18 m). We compared the results to reference values obtained from eight healthy peers (age: 33 ± 10 y).ResultsThe patients exhibited slight asymmetries in step length (smaller steps) and stance time (longer stance) as well as lower hip abduction moments in the operated limb in early stance compared to the non-operated limb. However, there were no differences in gait compared to healthy controls, even though the patients showed reduced bilateral hip abduction strength compared to controls.ConclusionsOur results indicate that the patients’ gait pattern had generally recovered very well, despite slight asymmetries in spatiotemporal parameters. Subtle deviations in hip abduction moments were observed during gait, whereas hip abduction strength was substantially reduced. Hence, the patients walked at a higher percentage of their maximal capacity. They may, therefore, be prone to fatigue and adopt compensatory gait strategies more quickly than healthy peers when walking long distances.

Stroke-related effects on maximal dynamic hip flexor fatigability and functional implications.

Stroke-related changes in maximal dynamic hip flexor muscle fatigability may be more relevant functionally than isometric hip flexor fatigability. Ten chronic stroke survivors performed 5 sets of 30 hip flexion maximal dynamic voluntary contractions (MDVC). A maximal isometric voluntary contraction (MIVC) was performed before and after completion of the dynamic contractions. Both the paretic and nonparetic legs were tested. Reduction in hip flexion MDVC torque in the paretic leg (44.7%) was larger than the nonparetic leg (31.7%). The paretic leg had a larger reduction in rectus femoris EMG (28.9%) between the first and last set of MDVCs than the nonparetic leg (7.4%). Reduction in paretic leg MDVC torque was correlated with self-selected walking speed (r2=0.43), while reduction in MIVC torque was not (r2=0.11). Reductions in maximal dynamic torque of paretic hip flexors may be a better predictor of walking function than reductions in maximal isometric contractions.

Relationship between hip abductor strength and external hip and knee adduction moments in medial knee osteoarthritis

BackgroundAlterations in hip abductor strength and hip and knee adduction moments during gait are associated with knee osteoarthritis. This study examines the relationship between hip abductor strength and hip and knee adduction moments during gait in individuals with symptomatic medial knee osteoarthritis. MethodsNinety-nine participants underwent maximal isometric hip abductor strength testing and 3D gait analysis. Pearson correlations examined relationships between non-normalized maximal hip abductor strength (Nm), peak external hip and knee adduction moments (Nm) and knee adduction moment impulse (Nm∙s). Linear regressions examined these relationships while controlling for body size (height and mass) and walking speed. FindingsPositive relationships existed between non-normalized hip abductor strength and hip and knee adduction moments (r=0.28 and 0.37, respectively, p<0.01) as well as the knee adduction moment impulse (r=0.47, p<0.01). However, after controlling for body size and walking speed, hip abductor strength was not a significant predictor of hip or knee adduction moments (B=−0.08, and 0.04, respectively, p>0.05) but was a significant predictor of knee adduction moment impulse (B=0.05, p=0.005), explaining 6% of the variance. InterpretationWhile a significant relationship between hip abductor strength and knee adduction moment impulse was noted, hip abductor strength only explained a small amount of variance in the impulse. Our findings support previous research of healthy individuals and those with mild to moderate knee osteoarthritis and suggests hip abductor strength has little influence on hip and knee adduction moments during gait.

Associations between iliotibial band injury status and running biomechanics in women

Iliotibial band syndrome (ITBS) is a common overuse knee injury that is twice as likely to afflict women compared to men. Lower extremity and trunk biomechanics during running, as well as hip abductor strength and iliotibial band flexibility, are factors believed to be associated with ITBS. The purpose of this cross-sectional study was to determine if differences in lower extremity and trunk biomechanics during running exist among runners with current ITBS, previous ITBS, and controls. Additionally, we sought to determine if isometric hip abductor strength and iliotibial band flexibility were different among groups. Twenty-seven female runners participated in the study. Participants were divided into three equal groups: current ITBS, previous ITBS, and controls. Overground running trials, isometric hip abductor strength, and iliotibial band flexibility were recorded for all participants. Discrete joint and segment biomechanics, as well as hip strength and flexibility measures were analyzed using a one-way analysis of variance. Runners with current ITBS exhibited 1.8 (1.5)° greater trunk ipsilateral flexion and 7 (6)° less iliotibial band flexibility compared to runners with previous ITBS and controls. Runners with previous ITBS exhibited 2.2 (2.9) ° less hip adduction compared to runners with current ITBS and controls. Hip abductor strength 3.3 (2.6) %BM×h was less in runners with previous ITBS but not current ITBS compared to controls. Runners with current ITBS may lean their trunk more towards the stance limb which may be associated with decreased iliotibial band flexibility.

M-mode ultrasound used to detect the onset of deep muscle activity

M-mode ultrasound imaging (US) reflects motion of connective tissue within muscles. As muscle contraction is accompanied by motion of muscle tissue, M-mode US may be used to measure non-invasively the onset of deep muscle activity. Isometric hip abduction was measured on nine healthy subjects in the deep region of the gluteus medius muscle and in gluteus minimus by fine-wire electromyography (EMG) and M-mode US. Following signal transformation with the Teager–Kaiser Energy Operator, EMG and M-mode US onsets of muscle activity were computer-processed. Correlation between log-transformed EMG and M-mode high-energy onsets was higher in gluteus medius (r 0.93) than in gluteus minimus (r 0.86). M-mode high-energy onsets followed EMG onset by median 33 (IQR 53) ms in gluteus medius, and by 17 (IQR 63) ms in gluteus minimus. 4% of gluteus medius and 23% of gluteus minimus M-mode onsets were detected before EMG onset. Using a higher onset threshold reduced the rate of onsets detected before EMG but also prediction accuracy. In voluntary activation, M-mode US high-energy onsets were closely related to EMG-measured onsets, but the time interval between both measures varied. The relationship of electrical and mechanical activation onsets appears to be influenced by modifying factors which may differ between muscles.

Preferential vastus medialis oblique activation and its effectiveness in patellofemoral pain syndrome: A review of literature-an update

To review recent literature regarding evidences for best possible exercises and methods that are proposed for preferential vastus medialis oblique (VMO) activation and effectiveness of preferential VMO activation in patellofemoral pain syndrome (PFPS) patients. The review of recent literature supports preferential VMO activation as one of the efficient management protocols in PFPS patients. Although there is quite heterogeneity in the available research, a majority of research suggests close kinetic chain (CKC) exercises to be more beneficial also the CKC squatting exercise with full maximum voluntary isometric contraction hip adduction has been an exercise quite supported by the recent researches for preferential VMO activation. It can be augmented via other methods like taping, biofeedback, motor imagery, unstable surface to enhance the VMO activation. In accordance with the review of recent literature, preferential VMO activation also has been very well correlated with a reduction in pain, enhancement in function in PFPS patients.

背臥位におけるハンドヘルドダイナモメーターを使用した等尺性股関節伸展筋力の測定

背臥位におけるハンドヘルドダイナモメーターを使用した等尺性股関節伸展筋力の測定

等尺性股関節伸展運動における膝関節角度の影響

等尺性股関節伸展運動における膝関節角度の影響

Effects of hip joint center location and femoral offset on abductor muscle strength after total hip arthroplasty

Objectives. The purposes of this study were 1) to examine the changes in the hip joint center (HJC) position and the femoral offset (FO) after total hip arthroplasty (THA) and 2) to investigate the effects of the HJC and FO on isometric abductor muscle strength.Methods. We evaluated 51 patients who underwent unilateral primary THA. The FO, and horizontal and vertical distances from the HJC to the tip of the teardrop were measured and isometric hip abductor muscle strength was measured.Results. The HJC of the affected side moved medially postoperatively compared with that of the unaffected side (p < 0.05), and the FO was reconstructed similarly to the unaffected side. There were significant negative correlations between the changes in the horizontal distance from the HJC and FO to the tip of the teardrop. An increase in the FO and infero-medial cup position optimized hip abductor muscle strength.Conclusion. The HJC was reconstructed medially and superiorly, and the change in the FO after THA was influenced by the change in the horizontal distance of the HJC. Multiple regression analysis revealed that the medial and inferior HJC and increase in the FO constitute an effective procedure for restoring abductor strength.

Relationship between physical impairments and movement patterns during gait in patients with end-stage hip osteoarthritis.

Patients with hip osteoarthritis demonstrate limited range of motion, muscle weakness, and altered biomechanics; however, few studies have evaluated the relationships between physical impairments and movement asymmetries. The purpose of this study was to identify the physical impairments related to movement abnormalities in patients awaiting total hip arthroplasty. We hypothesized that muscle weakness and pain would be related to greater movement asymmetries. Fifty-six subjects who were awaiting total hip arthroplasty were enrolled. Pain was assessed using a 0-10 scale, range of motion was assessed with the Harris Hip Score and isometric hip abductor strength was tested using a hand-held dynamometer. Trunk, pelvis and hip angles and moments in the frontal and sagittal planes were measured during walking using three dimensional motion analysis. During gait, subjects had 3.49 degrees less peak hip flexion and 8.82 degrees less extension angles (p < 0.001) and had 0.03 Nm/k*m less hip adduction moment on the affected side (p = 0.043). Weaker hip muscles were related to greater pelvis (r = -0.291) and trunk (r = -0.332) rotations in the frontal plane. These findings suggest that hip weakness drives abnormal movement patterns at the pelvis and trunk in patients with hip osteoarthritis to a greater degree than hip pain.