Human standing: does the control strategy preprogram a rigid knee?

Groin pain and hip range of motion is different in Indigenous compared to non-Indigenous young Australian football players

Effects of plantarflexion on pelvis and lower limb kinematics

Comparison of muscle activity of hamstrings as knee flexors and hip extensors and effect of tibial and hip rotation on the contribution of hamstrings

These abstracts are presented here as prepared by the authors. The accuracy and content of each abstract remain the responsibility of the authors. In the identification number above each abstract, SPO designates a Sports Physical Therapy Section poster presentation. J Orthop Sports Phys Ther 2014;44(1):A159–A191. doi:10.2519/jospt.2014.44.1.A159

Activation of the gluteus maximus, gluteus medius and tensor fascia lata muscles during hip internal and external rotation exercises at three hip flexion postures

This cross-sectional study aimed to determine normative values for hip strength and range of motion in professional female football players and to explore associations of age, playing position, leg dominance, hip/groin symptoms and previous hip/groin injuries. By establishing baseline measures, this study aims to provide reference values that can help guide injury prevention strategies in female football players. Cross-sectional. 100 professional female football players from the highest Dutch football league (Eredivisie) were assessed at three participating hospitals. Primary outcome measures included normalized eccentric hip adduction and abduction (Nm/kg), hip adduction/abduction ratio, adduction squeeze (N/kg), internal and external hip rotation (°), total hip rotation (°), hip flexion (°) and bent knee fall out (cm). Normative values for hip strength (mean ± SD) were: adduction 3.0 ± 0.6 Nm/kg, abduction 3.1 ± 0.6 Nm/kg, adduction/abduction ratio 1.0 ± 0.1, and adductor squeeze 4.2 ± 0.7. Age showed a positive association with abduction and adduction strength. Goalkeepers had lower values for all strength measurements compared with field players. Normative values for ROM (mean ± SD) were: internal rotation 36 ± 8°, external rotation 49 ± 7°, total rotation 86 ± 10°, hip flexion 128 ± 6°, and bent knee fall out 14 ± 4 cm. Dominant legs showed lower mean values for internal rotation, total rotation, and hip flexion compared to non-dominant legs. This study established normative values for hip strength and range of motion in professional female football players that can be used as reference profiles and can aid in injury prevention strategies and return-to-play protocols.

Background: Persistent rotatory instability after anterior cruciate ligament (ACL) reconstruction may be a result of unaddressed insufficiency of the anterolateral structures. Recent publications about the anatomy of the anterolateral ligament (ALL) have led to a renewed interest in lateral extra-articular procedures, and several authors have proposed ALL reconstruction to supplement intra-articular ACL reconstruction. However, only limited knowledge about the biomechanical characteristics of the ALL exists. Purpose/Hypothesis: The purpose of this study was to analyze length changes of the ALL during passive knee motion. The study hypothesis was that the ALL lengthens with knee flexion and internal tibial rotation. Study Design: Controlled laboratory study. Methods: The ALL of 6 cadaveric knees was dissected. Specimens were mounted in a specifically designed test rig that allowed unconstrained passive flexion/extension movement between 0° and 90° as well as external/internal tibial rotation of 25° at various flexion angles. Highly elastic, capacitive polydimethylsiloxane strain gauges were attached to the insertion sites of the ALL. Length changes were recorded continuously at flexion angles between 0° and 90° and during internal/external tibial rotation at 0°, 15°, 30°, 45°, 60°, 75°, and 90°. All measurements were calculated as the relative length change (%) of the ALL compared with 0° of flexion and neutral rotation. Results: The mean relative length of the ALL significantly increased with increasing knee flexion (P < .001), with an estimated mean length change of +0.15% per degree. Both internal and external tibial rotation were independent determinants for length change; internal rotation significantly increased the length of the ALL (P < .001), whereas external rotation significantly decreased its length (P < .001). The mean length change with internal rotation increased with knee flexion, with a significantly greater length change at 90° compared with 0° (P = .048), 15° (P = .033), and 30° (P = .015). The maximum mean length change was +33.77% ± 9.62%, which was observed at 25° of internal rotation and 90° of flexion. Conclusion: The ALL is a nonisometric structure that tensions with knee flexion and internal tibial rotation. Length changes with internal rotation were greater at higher flexion angles, with the greatest length change of the ALL observed at 90° of flexion. Clinical Relevance: The ALL can be considered a stabilizer against internal tibial rotation, especially at deep flexion angles. With regard to ALL reconstruction procedures, tensioning and fixation of the graft should be performed near 90° of flexion because graft tensioning near extension may cause excessive ligament strain with increasing knee flexion.

Martín-Miguel, I, Torrontegi-Ronco, E, Martínez-Ortega, JdD, Moreno-Martín, A, and Montalvo-Zenarruzabeitia, Z. Relative values of maximal isometric strength in lower limbs across different sports disciplines in high-performance athletes. J Strength Cond Res 39(8): e982-e990, 2025-This study aimed to establish reference values for relative strength in lower limb dynamometry among high-performance athletes across various sports disciplines and to compare the differences in relative strength between these disciplines. In total, 297 elite athletes (female athletes:155; male athletes:142) from 26 different sports participated, grouped into categories such as team sports, gymnastics, combat sports, racket sports, endurance, power track and field, weightlifting, and other. Relative strength was measured using a dynamometer through maximal isometric contractions. Knee extension and ankle plantar flexion were the tests with the highest strength application in both sexes, while external hip rotation and hip abduction showed the least force application. Analysis of variance revealed differences based on the test and sports discipline ( p < 0.05). Female athletes showed differences in hip abduction, hip extension, hip flexion, knee extension, knee flexion, and ankle plantar flexion, with gymnastic sports demonstrating greater strength, particularly compared with team sports and endurance. In male athletes ( p < 0.05), endurance sports showed lower strength in external hip rotation compared with racket sports, and in hip abduction compared with combat sports. The agonist-antagonist ratio indicated greater strength in internal hip rotation, hip flexion, knee extension, and ankle plantar flexion in both sexes, and hip abduction in female athletes and hip adduction in male athletes, compared with their antagonists. Significant differences were found in the hip adduction-abduction and ankle plantar-dorsal flexion ratio in gymnastics compared with the rest of sports. These findings can be used to assess athletes' physical condition, prevent injuries, and facilitate rehabilitation to optimize performance.

Background:There is a renewed interest in examining the association between hip range of motion and injury in athletes, and the data on baseball players are conflicting. Understanding whether asymmetrical hip rotation is a normal adaptation or a risk factor for injury will help therapists, trainers, and physicians develop rehabilitation programs to improve kinetic energy transfer and prevent injury. As our knowledge of hip pathology among baseball pitchers improves, establishing baselines for hip motion is critical in the further assessment of injury.Hypothesis:Because of the repetitive nature of throwing sports and the adaptive changes documented in the shoulder, elite baseball pitchers would have characteristic patterns of hip internal and external rotations on their dominant throwing side (stance) and their nondominant side (stride) in extension.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Computer software was used to measure passive internal and external rotations on digital photographs of 111 professional baseball pitchers.Results:In right-handed pitchers, there was significantly more internal rotation in the stance hip than the stride hip (32.2° ± 8.2° vs 30.8° ± 8.4°; P = .0349) and significantly more external rotation in the stride hip than the stance hip (36.3° ± 7.7° vs 30.8° ± 9.7°; P < .0001). While the mean difference in external rotation was 4.7°, 32% of the subjects had a >10° increase in external rotation on the stride hip relative to the stance hip. This population was statistically different from the remaining group for older age (P = .0053), lower body mass index (P = .0379), and more years in professional baseball (P = .0328). In the smaller number of left-handed pitchers, side-to-side differences in hip rotation were found but were not statistically significant.Conclusion:Pitchers showed more internal rotation on their stance hip and more external rotation on their stride hip. Although the mean differences are small, there is a subset of pitchers with defined characteristics in whom larger differences exist.

Hip and shoulder internal rotation range of motion deficits in professional tennis players

Purpose of the present cohort study was the determination of lower body function and rotation in patients with symptomatic component mal-rotation after total knee arthroplasty using instrumented 3D gait analysis. A consecutive series of 12 patients (61.3years ± 11.4years) were included suffering under remaining pain or limited range of motion at least six months after total knee arthroplasty. A CT-scan according to the protocol of Berger et al. and instrumented 3D gait analysis were carried out including clinical examination, videotaping, and kinematic analysis using a Plug-in Gait model. Outcome variables were temporospatial parameters as well as kinematics in sagittal and transversal plane. Data for reference group were collected retrospectively and matched by age and gender. Temporospatial parameters of the study group showed decreased velocity, cadence, and step length as well as increased step time. Single limb support was reduced for the affected limb. In sagittal plane, maximum knee flexion during swing phase was reduced for the replaced knee joint. In transverse plane, there was hardly any difference between affected and non-affected limb. Compared to the reference group, both limbs show significant increased internal ankle rotation and external hip rotation. There were significant strong linear correlations between ankle rotation and hip rotation as well as ankle rotation and radiological tibial mal-rotation. Patients with symptomatic component mal-rotation after total knee arthroplasty showed typically functional deficits. The affected and non-affected limb showed significant increased internal ankle rotation and external hip rotation, while only the affected, replaced knee showed reduced internal knee rotation. Identification of rotational abnormalities of hip and ankle joints seems to be mandatory in TKA to identify the patient group with external hip rotation, internal ankle rotation, and an elevated risk for symptomatic rotational TKA component mal-alignment.

Internal hip rotation in cerebral palsy (CP) is typically treated with a femoral derotation osteotomy. This has been shown to be largely a successful procedure but recurrence rates up to 41% have been reported. Reported risk factors include younger age, reduced hip joint impulse and ankle plantar-flexion. We report on two patients with bilateral CP demonstrating recurrent unilateral internal hip rotation despite surgical intervention(s). Both demonstrate a number of the reported risk factors for recurrence. In addition, this case report specifically compared gait kinematic patterns pre and post recurrence. On comparing both patient’s hip rotation and ankle dorsi/plantarflexion kinematics they are seen to be almost identical both pre-operatively and post-operatively. Both patients appear to revert to approximately 30o of internal hip rotation which has been shown to maximise hip abductor function. Therefore, this case report suggests that surgical derotation in isolation is unlikely to be successful in this group and we suggest that this hip and ankle pattern may help predict recurrence in unilateral internal hip rotation.

Associations among hip motions, knee abduction and internal rotation motion during a drop vertical jump (DVJ), which increases the risk of anterior cruciate ligament injury, remain unclear. The purpose of this study was to examine associations among knee abduction, internal rotation and hip joint motions during a DVJ. Fifty-seven young female participants performed a DVJ from a 30-cm height. Hip and knee kinematics and kinetics were analysed using a three-dimensional motion analysis system and force plates. Multiple regression analysis showed that peak knee abduction angle was negatively associated with knee internal rotation and hip internal rotation excursions from initial contact (IC) to peak knee flexion, and positively associated with peak knee abduction moment (R2 = 0.465, P< 0.001). Peak knee internal rotation angle was negatively associated with the hip flexion excursion from IC to peak knee flexion and peak hip adduction moment (R2 = 0.194, P= 0.001). In addition, hip internal rotation excursion was negatively associated with knee abduction and internal rotation excursion from IC to 50 ms after IC. To avoid a large knee abduction and internal rotation motion during jump-landing training, it might be beneficial to provide landing instructions to avoid a large hip external rotation motion.

Trunk, pelvis and lower limb coordination between anticipated and unanticipated sidestep cutting in females

Few studies have explored the relationship between muscle strength, range of motion (ROM), and balance in the horizontal plane of the hip joint using three-dimensional (3D) motion analysis. We investigate the relationships of hip internal rotation (IR) and external rotation (ER) ROM, measured using a 3D motion capture system, with hip internal and external rotator strength and single-leg standing balance. The participants were 40 healthy adults. Kinematic data on hip ROM were collected using an eight-camera motion analysis system. Hip rotational strength measurements were obtained using hand-held isometric dynamometry. A Single-leg standing test and a pendular test were conducted to evaluate static and dynamic balance ability using BioRescue. Significant correlations were found between hip strength and each variable measured during hip ROM assessments (p< 0.05). Significant positive correlations were found between the hip IR/ER strength ratio and the IR/ER ROM ratio (r= 0.72, p< 0.01). The subgroup with a normal IR/ER ratio of hip rotator strength and ROM showed significantly better dynamic balance ability than the subgroup with a hip rotator muscle imbalance (p< 0.05). There is a significant relationship between hip IR/ER strength and IR/ER ROM with a normal hip IR/ER strength and ROM ratio positively affecting dynamic balance ability.