Journal articles on the topic 'Hip abductors .Hip external rotators .Peak torque'

Aim. To explore whether the eccentric muscle strength of both hip abductors and external rotators differ in participants with subacute lateral ankle sprain and healthy population, and to compare the Biodex balance measures as well. Material and methods. Thirty males diagnosed as a second degree ankle sprain enrolled in this study, while twenty-nine healthy volunteers considered as controls. The study measured both the peak eccentric torque for both hip abductors and external rotators using Biodex isokinetic dynamometer. All participants examined for bilateral and unilateral balance ability using Biodex balance system from erect position to determine total stability index (SI), anteroposterior index (API), and mediolateral index (MLI). Results. A detected significant negative correlation was obvious between peak eccentric isokinetic testing for hip external rotators torque; and total SI, API, and MLI of all the Biodex balance system measures for bilateral stance and API in unilateral stance. While, a moderate significant positive correlation found for peak eccentric isokinetic torques between both hip external rotators and abductors. Conclusion. Decreased hip muscle strength can increase the vulnerability of ankle ligaments via minimizing the postural control during weight-bearing activities, which, in turn, stimulates the compensatory neuromuscular mechanisms.

Context:Assessment of hip strength can be performed with either isokinetic or isometric testing procedures, but the degree of association between values derived from the alternative testing methods has not been previously documented.Objective:To investigate the relationship between isometric peak torque and isokinetic peak torque at 60°·s-1 for various hip motions.Participants:Eighteen physically active males (N = 9) and females (N = 9) participated (22 ± 3 years, 173.0 ± 10.5 cm, 73.8 ± 16.7 kg).Intervention(s):Three isokinetic repetitions at 60°·s-1 and three isometric contractions of 5 s each for the hip fexors (HFs), hip extensors (HEs), hip abductors (ABs), hip adductors (ADs), hip external rotators (ERs), and hip internal rotators (IRs).Outcome Measures:Pearson correlation coefficients and coefficients of determination were calculated for both absolute and allometric-scaled peak torque values.Results:Meaningful associations between isometric and isokinetic peak torque values were found for each hip motion. Allometric-scaled strength values demonstrated stronger correlations than absolute strength values.Conclusions:The results suggest that portable fixed isometric testing of hip strength is an alternative to isokinetic testing at 60°·s-1.

Abstract Context: Individuals suffering from patellofemoral pain have previously been reported to have decreased isometric strength of the hip musculature; however, no researchers have investigated concentric and eccentric torque of the hip musculature in individuals with patellofemoral pain. Objective: To compare concentric and eccentric torque of the hip musculature in individuals with and without patellofemoral pain. Design: Case control. Setting: Research laboratory. Patients or Other Participants: Twenty participants with patellofemoral pain (age = 26.8 ± 4.5 years, height = 171.8 ± 8.4 cm, mass = 72.4 ± 16.8 kg) and 20 control participants (age = 25.6 ± 2.8 years, height = 169.5 ± 8.9 cm, mass = 70.0 ± 16.9 kg) were tested. Volunteers with patellofemoral pain met the following criteria: knee pain greater than or equal to 3 cm on a 10-cm visual analog scale, insidious onset of symptoms not related to trauma, pain with palpation of the patellar facets, and knee pain during 2 of the following activities: stair climbing, jumping or running, squatting, kneeling, or prolonged sitting. Control participants were excluded if they had a prior history of patellofemoral pain, knee surgery in the past 2 years, or current lower extremity injury that limited participation in physical activity. Intervention(s): Concentric and eccentric torque of the hip musculature was measured on an isokinetic dynamometer. All volunteers performed 5 repetitions of each strength test. Separate multivariate analyses of variance were performed to compare concentric and eccentric torque of the hip extensors, abductors, and external rotators between groups. Main Outcome Measure(s): Average and peak concentric and eccentric torque of the hip extensors, abductors, and external rotators. Torque measures were normalized to the participant's body weight multiplied by height. Results: The patellofemoral pain group was weaker than the control group for peak eccentric hip abduction torque (F1,38 = 6.630, P = .014), and average concentric (F1,38 = 4.156, P = .048) and eccentric (F1,38 = 4.963, P = .032) hip external rotation torque. Conclusions: The patellofemoral pain group displayed weakness in eccentric hip abduction and hip external rotation, which may allow for increased hip adduction and internal rotation during functional movements.

Background: Patellofemoral pain syndrome (PFPS) is sometimes related to excessive hip adduction and internal rotation, as well as knee valgus during weightbearing activities in females. Research on injury prevention and rehabilitation strategies has shown the positive effects of valgus control instruction (VCI) exercise programs in training. Hypothesis: A VCI program would result in a positive change in pain, eccentric hip muscle torque, and performance in females with PFPS. Study Design: Controlled laboratory study. Level of Evidence: Level 1. Methods: Sixty-four amateur female volleyball players from our university (age, 18-25 years) with PFPS and equal years of exercise experience were randomly divided into VCI (n = 32; age, 22.1 ± 5.88 years) and control (n = 32; age, 23.1 ± 6.49 years) groups. Function (single, triple, and crossover hops), strength (hip abductor and external rotators), pain (visual analog scale), and knee valgus angle (single-leg squat) were assessed at baseline and after intervention. Results: There was a significant difference before and after implementation of the VCI program with regard to pain (49.18% ↓, P = 0.000), single-leg hop test (24.62% ↑, P = 0.000), triple-hop test (23.75% ↑, P = 0.000), crossover hop test (12.88% ↑, P = 0.000), single-leg 6-m timed hop test (7.43% ↓, P = 0.000), knee dynamic valgus angle (59.48% ↓, P = 0.000), peak abductor to adductor eccentric torque ratio (14.60% ↑, P = 0.000), peak external (59.73% ↑, P = 0.023) and internal rotator (15.45% ↑, P = 0.028) eccentric torques, and the ratio of peak external to internal rotator eccentric torque (40.90% ↑, P = 0.000) ( P < 0.05). Conclusion: PFPS rehabilitation and prevention programs should consider VCI exercises to decrease pain, improve strength, and increase athletes’ functional performance. Clinical Relevance: This study investigated the effect of VCI exercises on knee valgus angle, pain, and functionality of individuals with PFPS. The VCI program improves performance, knee dynamic valgus angle, and strength in participants with PFPS. A controlled and optimal knee valgus angle during a functional task is the most important factor for injury prevention specialists. VCI training can be used as a supplemental method to prevent and treat lower extremity injury in patients with PFPS.

Although relationships between lower limb injury and core strength and endurance have been reported, limited research on the risk of knee injury specifically among soccer players exists. This study aimed to compare preseason trunk muscle endurance as well as trunk and hip muscle strength between soccer players who experienced knee in- jury during their season and those who did not. Dependent variables were also used to predict the risk for injury. This prospective cross-sectional study involved thirty-nine male soccer players (age 19.64±2.84 years, weight 73.94±15.66 kg and height 175.67±9.92 cm). By the end of the season, twelve (30.77%) reported knee injuries. Accordingly, two groups were identified and compared: injured and non-injured. Prone-bridge, side-bridge, trunk flexion and hor- izontal back extension hold times were used as trunk endurance measures, while peak isokinetic trunk flexor and extensor torques, as well as hip abductor and external rotator torques, were recorded as strength measures. MANOVA showed that only prone-bridge hold time was significantly higher in the non-injured players (p<0.05). Logistic re- gression showed that prone-bridge hold time and peak isokinetic hip abductor torque were significant predictors of injury (OR=0.97&0.03, respectively). Thus, soccer players with knee injuries have lesser core endurance. Reduced prone-bridge hold time and abductor torque, specifically, are associated with an increased risk of injury.

Objectives: This study aimed to compare three-dimensional kinematic of the trunk, pelvis, hip, and knee during the single-leg squat and hip torque in individuals with and without isolated patellofemoral osteoarthritis (PFOA). Patients and methods: This cross-sectional study evaluated trunk, pelvis, hip, and knee kinematics at 30°, 45°, and 60° knee flexion during the single-leg squat using the Vicon motion capture and analysis system, the Nexus System 2.1.1, and 3D Motion Monitor software. Sixteen individuals (8 males, 8 females; mean age: 49.3±6.2 years; range 40 to 61 years) participated in the study, of which eight were PFOA patients and eight were healthy controls. Isometric hip abductor, extensor, and external rotator torques were evaluated using a handheld dynamometer. Results: The PFOA group exhibited greater hip adduction at 30° (p=0.008), 45° (p=0.005), and 60° (p=0.008) knee flexion in the descending phase of the single-leg squat, as well as at 60° (p=0.009) and 45° (p=0.03) knee flexion in the ascending phase. No significant differences were found between groups for other kinematic variables (p>0.05). The PFOA group exhibited lower isometric hip abductor (p=0.02), extensor (p< 0.001), and external rotator (p=0.007) torques. Conclusion: Individuals with PFOA exhibited excessive hip adduction that could increase stress on the lateral patellofemoral joint at 30°, 45°, and 60° knee flexion during the single-leg squat and exhibited weakness of the hip abductors, extensors, and external rotators in comparison to healthy controls.

Change-of-direction (CoD) ability is an important determinant of athletic performance. Muscle strength is among the most important determinants of CoD ability. However, previous studies investigating the relationship between CoD ability and muscle strength focused mostly on flexor and extensor muscle groups, or used multi-joint exercises, such as jumps, squats or mid-thigh pull. The purpose of the present study was to investigate the relationship between CoD ability and strength of ankle, knee, hip and trunk maximal and explosive strength. The participants (n = 327), consisting of male and female basketball players, tennis players and long-distance runners completed isometric strength assessments and CoD testing (90° and 180° turn tests). The times of both CoD tests were associated with muscle strength (peak torques and the rate of torque development variables), with correlation coefficients being mostly weak to moderate (r = 0.2–0.6). Strength variables explained 33%, 62% and 48% of the variance in the 90° turn task, and 42%, 36% and 59% of the variance in the 180° turn task, in basketball players, long-distance runners and tennis players, respectively. Hip and trunk muscle strength variables were the most prevalent in the regression models, especially hip adduction and abduction strength. Our results suggest that the strength of several lower limb muscles, in particular of the hip abductors and adductors, and trunk muscles, but also hip rotators, extensors and flexors, as well as knee and ankle flexors and extensors should be considered when aiming to improve CoD performance.

Background: Medial tibial stress syndrome also called shin splints; the incidence ranges 4-35% in athletic& military populations present with medial tibial stress syndrome .Pain at posteromedial tibia. The pain is cumulative with activity & persists for a long time. Purpose: this study was conducted to determine the hip muscles? peak torque in medial tibial stress syndrome. Subjects and methods: forty participants were included in this study divided into two groups, group A (20 subjects with MTSS) ,While group B(20 normal subjects) both groups were assessed for hip abductors, adductors, external rotators and internal rotators peak torque through Isokinetic Biodex system. Results: indicated that there was a significant decrease in the hip abductors? peak torque (p = 0.001) and the hip adductors? peak torque (p = 0.008) in the MTSS group compared with normal group, but There was no significant difference in the hip internal rotators? peak torque (p=0.059) and the hip external rotators? peak torque (p = 0.8) between the MTSS and normal. Conclusion : Participants with medial tibial stress syndrome demonstrated significantly decrease in the hip abductors? and adductors? peak torque, with regard to this study results, we concluded that, weakness of hip abductors is one of the causes of medial tibial stress syndrome Accordingly, it is needed to focus in our (rehabilitation and prevention strategies) on strengthening exercises for hip abductors .

Context: Hip muscle strength and hop performance limb symmetries after anterior cruciate ligament reconstruction (ACLR) are not well studied. This study aimed to determine the differences in hip abductors’ (ABD) and external rotators’ (ER) muscle strength measures between limbs, and the relationship between hip ABD and ER muscle strengths and hop performance limb symmetry indices (LSIs) 2 years after ACLR. Design: Cross-sectional study. Methods: Forty (level I/II) men athletes 2 years after unilateral ACLR completed 4 single-legged hop tests and involved hip ABD and ER strength testing (maximum voluntary isometric contraction [MVIC]; isokinetic peak torque [PKTQ] at 60°, 180°, and 300°/s; and isotonic peak velocity at 75% of their MVICs). Muscle strength measures were normalized to body mass, and hop performances were reported as LSIs. Paired t test was used to determine strength differences between limbs, and the Pearson correlation coefficient was used to assess the relationship between involved hip muscle strength measures and hop performance LSIs. Results: Hip ER-MVIC (involved: 60.26 [12.01], uninvolved: 63.68 [13.17] N·m/kg) and ER eccentric PKTQ at 60°/s (involved: 32.59 [9.28]; uninvolved: 35.73 [10.50] N·m/kg) were significantly different between limbs (P ≤ .018). Single-hop LSI correlated with hip ER-PKTQ at 180°/s (r = .354) and 300°/s (r = .324, P ≤ .041), while triple-hop LSI correlated with hip ER-MVIC (r = .320), concentric ER-PKTQ at 180°/s (r = .355), eccentric ER-PKTQ at 60°/s (r = .314), and hip ABD-PKTQ at 60°/s (r = .364) and 300°/s (r = .336, P ≤ .049). Conclusions: Men athletes demonstrated symmetrical hop performance and hip muscle strengths, except for ER hip’s MVIC and isokinetic eccentric peak torque at 60°/s 2 years after ACLR. Hop performance LSIs had a few, yet positive moderate relationships with involved hip ABDs and ER strength measures. This may indicate that hip ABD and ER muscle strength measures contribute to athletes’ hop performances 2 years after ACLR. Post-ACLR rehabilitation programs might incorporate hip muscle strengthening training to improve athletes’ functional performances.

The running performance and strength is important for many runners. This study aimed to examine hip joint isokinetic strength profiles of elite middle-distance runners. Nine elite middle-distance runners volunteered to participate in this study. Hip joint isokinetic muscle strength was measured using by an isokinetic dynameters. Participants performed isokinetic tests on dominant and non-dominant legs at a speed of 60°-s-1 for 10 repetitions. Isokinetic tests were conducted to flexion/extension, abduction/adduction and internal/external rotation movements of hip at concentric/concentric mode. There was no significant difference between dominant and non-dominant legs in peak torque and relative peak torque values. When the hip flexors were evaluated bilaterally, it was determined that the non-dominant side produced higher torque than the dominant side. However, in all other movements, the dominant side had higher torque values than the non-dominant side. As a result; on evaluated all joint movements bilaterally, hip flexor/extensor and adductor muscles were in normal values. However, hip abductor and internal/external rotator muscles values were in a risky range.

The presence of severe dynamic knee valgus in asymptomatic women may be a factor related to future complaints of pain in this joint. The aim of this study is to correlate the strength levels of hip and trunk stabilizer muscles with knee valgus angles, pelvic and trunk tilt in asymptomatic young women. 22 young women with no history of lower limb pain or injury participated in this study. In the first visit to the laboratory, the volunteers performed anamnesis, kinematic evaluation of the dynamic knee valgus angle, pelvic and trunk tilt. Afterwards, familiarization with muscle strength tests was made. On the second day, the evaluation of the maximal isometric muscle strength of the hip stabilizer muscles (lateral rotators, hip abductors and extensors) and trunk extensors was performed. For analysis of muscle strength data, the joint torque peak was used and, in relation to the kinematic data, the knee projection angles in the frontal plane, pelvis and trunk tilt, through the Kinovea software. Pearson's Correlation test showed no relationship between the hip and trunk muscle torque and the kinematic angles during the frontal and lateral step down. The muscle torque of the hip stabilizers and trunk extensors are not related to the movement pattern of the volunteers during the step down.

ABSTRACT Muscle strength is an essential part of the functional assessment of health professionals to select and analyze the effects of clinical interventions. This study aimed to determine the influence of gender and age on isometric strength of hip and knee muscle groups. A total of 127 subjects (50.4% men), aged from 20 to 49 years (stratified into three groups: 20-29 years; 30-39 years; and 40-49 years) participated in this study. A hand-held dynamometer was used to measure isometric normalized torque of the hip abductors, hip external rotators, knee extensors, and knee flexors muscles. Regressions and a two-way analysis of variance were used to identify the influence of age and gender on torque of each muscle group. Age and gender were included in the regression model for all groups. Generally, men aged 20-29 and 30-39 were stronger than age-paired women. For participants aged 40-49, torque was similar for men and women for all muscle groups. There was no difference among age groups for women. Generally, young men were stronger than older men. The association between age and gender in hip and knee strength was proved and liable of subgroup stratification after measurements with a hand-held isometric dynamometer.

ABSTRACT Objective: To correlate vertical (VFO) and horizontal (HFO) femoral offset with hip range of motion (ROM), peak muscle torque (PT), functional, capacity, and lower limb length in patients with total hip arthroplasty (THA). Methods: A cross-sectional case control study, in which 22 individuals (10 men and 12 women) - aged 61 (41-72), and within 23 (10-40) postoperative days - were evaluated for active hip ROM (fleximetry); Isometric PT (portable dynamometer); functional capacity (Timed up and Go test (TUG) and Harris Hip Score questionnaire); lower limb length (measuring tape); and VFO and HFO (radiographs). Results: The operated limb showed a reduction in length (p = 0.006), ROM for abduction (p = 0.001), flexion (p = 0.003), and external rotation (p = 0.003), as well as in all PT (p < 0.05) when compared with the contralateral limb. Moderate correlations were observed between VFO and external rotators (r = 0.487; p = 0.021); HFO and external rotators PT (r = −0.508; p = 0.016); and the difference between the VFO (operated and non-operated limb) and the TUG (r = −0.570; p = 0.006). Conclusion: Changes to the femoral offset seem to influence functional capacity, as well as the movement and external rotators PT of the hips in patients with THA, considering the postoperative period evaluated. Level of Evidence III, Case Control Study.

Objectives: Hip muscle function is affected by surgical intervention and is of particular concern when considering post-operative rehabilitation of the joint1. However, little is known about the dynamic, in vivo function of the hip muscles during activities of daily living. Marker-based motion capture studies have associated dysplastic hip anatomy with shorter abductor moment arm lengths during walking2, but these measurements are complicated by soft tissue artifact3. Biplane radiography is a highly accurate technique for measuring in vivo bone motion of the hip4 and has recently been utilized to estimate dynamic muscle moment arms, which are important factors influencing force and torque capabilities. Previous research studies utilizing biplane radiography have identified shorter muscle lengths and moment arms in the implanted hip compared to the contralateral hip of individuals with total hip arthroplasty during the double support phase of gait2, but normative in vivo moment arms of the hip musculature in asymptomatic individuals have yet to be established. Further, it remains unknown how moment arms change between activities of daily living, particularly during deep flexion activities that challenge hip stability. Developing a normative dataset of dynamic in vivo moment arm lengths would provide a valuable reference for clinicians and physical therapists developing rehabilitation protocols to strengthen the hip musculature and increase stability. The objective of this study was to determine in vivo moment arms of the hip abductors, adductors, and external rotators during gait and squatting in a cohort of asymptomatic adults. We hypothesized that the maximum moment arm length during squatting would be longer than during walking and static standing. Methods: Young adults with no history of hip surgery, chronic hip pathology, or severe lower extremity musculoskeletal injury were recruited to participate in this IRB-approved study. Participants performed bodyweight squats and treadmill walking within a biplane radiography system while ground reaction forces were collected at 1000 Hz from a dual-belt instrumented treadmill. The support phase of gait was defined by vertical ground reaction forces over 50 N. Synchronized biplane radiographs were collected at 50 images per second to image three trials of each hip for each activity. Subject-specific bone models of the pelvis and proximal femur were created from computed tomography (CT) scans (average 0.37x0.3 mm in-plane resolution, 0.625mm slice thickness). Coordinate systems5 and muscle origin and insertion points for the gluteus medius (hip abductor), gluteus minimus (hip abductor), pectineus (hip adductor), and grouped external rotators1 were identified based upon bony landmarks on the 3D bone models (Figure 1). In-vivo bone motion during each activity was determined by matching digitally reconstructed radiographs, created from the CT-based bone models, to the biplane radiographs using a registration process with a validated accuracy4 of 0.3mm. The line of action for each muscle segment was determined for each frame of the biplane radiographs as the vector from the muscle origin to the insertion. Moment arm length (MAL) was calculated for each frame of the dynamic biplane radiographs as the perpendicular distance between the hip joint center (acetabulum center) and the line of action of each muscle1 and interpolated to gait cycle for walking or percent maximum hip flexion during squatting. Differences between the maximum MAL during static standing, walking, and squatting were assessed within each muscle group using ANOVA with post-hoc pairwise comparisons performed as necessary. Results: Data from 186 trials of 43 hips from 22 individuals were included in the analysis (9M, 13F; mean age 22.0±2.2years; BMI 21.3±5.2kg/m2). Average walking velocity was 1.0±0.2m/s and the average maximum hip flexion during squatting was 101.6±16.1°. Average static standing MAL was greatest in the gluteus medius and smallest in the pectineus (Table 1). Maximum MAL was significantly different between all activities for all muscle groups (all p<0.001) (Table 1, Figure 2). Contrary to our hypothesis, moment arms of the abductors were smaller during squatting compared to other motions. Conclusions: This study demonstrates the in vivo torque generating capabilities of muscles surrounding the hip (reflected by their moment arm) change considerably from the standing position to positions encountered during active functional motions. Muscles involved in hip abduction and stabilization have less mechanical advantage at greater hip flexion, highlighting the importance of strengthening these muscle groups during rehabilitation. Specifically, moment arms of the hip abductors and external rotators are shorter during walking and squatting compared to standing, while moment arms of the adductors are shorter during walking and greater during squatting and standing. Knowledge of these postural changes in mechanical advantage can be useful when designing targeted rehabilitation protocols to strengthen the hip musculature and improve stability. Further research into relationships between dynamic in vivo hip muscle moment arms and lengths will yield additional insight into force and torque generating capacity of muscles during activities of daily living. These results are limited to treadmill walking and bodyweight squatting in asymptomatic young adults. References: Hu, et al., J Ortho Surg and Res. 2020. 2) Song, et al., J Biomech. 2020. 3) Fiorentino, et al., Gait Posture. 2017. 4) Martin, et al., J Arthroplasty. 2011. 5) Wu, et al., J Biomech. 2002. [Table: see text]

Change-of-direction (CoD) ability is an important determinant of athletic performance. Muscle strength is among the most important determinants of CoD ability. However, previous studies investigating the relationship between CoD ability and muscle strength focused mostly on flexor and extensor muscle groups, or used multi-joint exercises, such as jumps, squats or mid-thigh pull. The purpose of the present study was to investigate the relationship between CoD ability and strength of ankle, knee, hip and trunk maximal and explosive strength. The participants (n = 327), consisting of male and female basketball players, tennis players and long-distance runners completed isometric strength assessments and CoD testing (90˚ and 180˚ turn tests). The times of both CoD tests were associated with muscle strength (peak torques and the rate of torque development variables), with correlation coefficients being mostly weak to moderate (r = 0.2–0.6). Strength variables explained 33%, 62% and 48% of the variance in the 90˚ turn task, and 42%, 36% and 59% of the variance in the 180˚ turn task, in basketball players, long-distance runners and tennis players, respectively. Hip and trunk muscle strength variables were the most prevalent in the regression models, especially hip adduction and abduction strength. Our results suggest that the strength of several lower limb muscles, in particular of the hip abductors and adductors, and trunk muscles, but also hip rotators, extensors and flexors, as well as knee and ankle flexors and extensors should be considered when aiming to improve CoD performance.