Assessment of the influence of foot orthoses in the hip loading conditions during walking: a single case study

Despite their large clinical application, the understanding of the effects of foot orthoses on the lower limb kinematics and kinetics is limited. In this context, we propose an advanced musculoskeletal model to assess the influence of foot orthoses in the loading conditions within an osteoarthritic hip joint during gait. Experimental data are collected for a single pathological subject presenting a coxarthrosis (with and without orthoses), and a healthy subject during walking. An inverse dynamic approach coupled with an optimisation method evaluates the forces developed by 14 muscles and the hip contact reaction force. Contact reaction and muscular force magnitudes are closed whether the patient is walking with or without foot orthoses. Nevertheless, contact reaction amplitudes and orientations show differences in relation to those calculated for the healthy subject. The results obtained allow us to formulate some assumptions concerning the causes of coxarthrosis evolution and treatment.     

Orthoses posted in both the forefoot and rearfoot reduce moments and angular impulses on lower extremity joints during walking

The purpose of the present study was to determine the effects of orthoses designed to support the forefoot and rearfoot on the kinematics and kinetics of the lower extremity joints during walking. Fifteen participants volunteered for this study. Kinematic and kinetic variables during overground walking were compared with the participants wearing sandals without orthoses or sandals with orthoses. Orthoses increased knee internal abduction moment during late stance and knee abduction angular impulse, and reduced the medial ground reaction force during late stance, adduction free moment, forefoot eversion angle, ankle inversion moment and angular impulse, hip adduction angle, hip abduction moment, and hip external rotation moment and angular impulse (p<0.05). Orthoses decreased the torsional forces on the lower extremity and reduced the loading at the hip during walking. These findings combined with our previous studies and those of others suggest that forefoot abnormalities are critically important in influencing lower extremity kinematics and kinetics, and may underlie some non-traumatic lower extremity injuries.     

Effects of added trunk load and corresponding trunk position adaptations on lower extremity biomechanics during drop-landings

Although both trunk mass and trunk position have the potential to affect lower extremity biomechanics during landing, these effects are not well understood. Our overall hypothesis stated that both trunk mass and trunk position affect lower extremity biomechanics in landing. Thus, our purpose was to determine the effects of an added trunk load and kinematic trunk adaptation groups on lower extremity joint kinematics, kinetics, and energetics during drop-landings. Twenty-one recreationally active subjects were instrumented for biomechanical analysis. Subjects performed two sets of eight double-limb landings with and without 10% body weight added to the trunk. On lower extremity dependent variables, 2(condition: no load, trunk load)x2(group: trunk extensors vs. trunk flexors) ANOVAs were performed. Condition by group interactions at the hip showed differing responses to the added trunk load between groups where the trunk extensor group decreased hip extensor efforts ( downward decrease 11-18%) while the trunk flexor group increased hip extensor efforts ( upward increase 14-19%). The trunk load increased biomechanical demands at the knee and ankle regardless of trunk adaptation group. However, the percent increases in angular impulses and energy absorption in the trunk extensor group were 14-28% while increases in the trunk flexor group were 4-9%. Given the 10% body weight added to the trunk, the 14-28% increases at the knee and ankle in the trunk extensor group were likely due to the reduced hip extensor efforts during landing. Overall these findings support our overall hypothesis that both trunk mass and trunk position affect lower extremity biomechanics during vertically oriented landing tasks.     

Gender comparisons between unilateral and bilateral landings

The increased number of women participating in sports has led to a higher knee injury rate in women compared with men. Among these injuries, those occurring to the ACL are commonly observed during landing maneuvers. The purpose of this study was to determine gender differences in landing strategies during unilateral and bilateral landings. Sixteen male and 17 female recreational athletes were recruited to perform unilateral and bilateral landings from a raised platform, scaled to match their individual jumping abilities. Three-dimensional kinematics and kinetics of the dominant leg were calculated during the landing phase and reported as initial ground contact angle, ranges of motion (ROM) and peak moments. Lower extremity energy absorption was also calculated for the duration of the landing phase. Results showed that gender differences were only observed in sagittal plane hip and knee ROM, potentially due to the use of a relative drop height versus the commonly used absolute drop height. Unilateral landings were characterized by significant differences in hip and knee kinematics that have been linked to increased injury risk and would best be classified as "stiff" landings. The ankle musculature was used more for impact absorption during unilateral landing, which required increased joint extension at touchdown and may increase injury risk during an unbalanced landing. In addition, there was only an 11% increase in total energy absorption during unilateral landings, suggesting that there was a substantial amount of passive energy transfer during unilateral landings.     

Sex-Specific associations between hip muscle strength and foot progression angle

The foot progression angle (FPA) influences knee loading during gait, but its determinants are unclear. The purpose of this study was to compare FPA between males and females and also examine the association between lower extremity kinematics during gait, hip strength, and the FPA. 25 males and 25 females completed 5 gait trials while FPA and frontal and transverse plane hip and knee angles were calculated from the dominant limb during the foot flat portion of stance. Hip extensor/flexor, abductor/adductor, and internal/external rotator strength were evaluated using maximum voluntary isometric contractions. One-way MANOVAs compared gait and strength outcomes. Stepwise regression assessed the association between FPA, and MVIC and kinematics after accounting for speed in males and females. There was no difference in FPA between sexes (p > 0.05), but females had greater frontal and transverse plane hip angles compared with males (all p < 0.05). Greater hip abduction (p = 0.02) strength was associated with greater FPA, but only in males. In males, greater hip abductor strength may contribute to a more neutral position of the foot during gait, which could help maintain an equal knee loading distribution. Our results suggest that there are sex specific control strategies to achieve a similar FPA during gait.     

The effects of repetitive drop jumps on impact phase joint kinematics and kinetics

The purpose of the study was to investigate the effects of fatigue on lower extremity joint kinematics, and kinetics during repetitive drop jumps. Twelve recreationally active males (n = 6) and females (n = 6) (nine used for analysis) performed repetitive drop jumps until they could no longer reach 80% of their initial drop jump height. Kinematic and kinetic variables were assessed during the impact phase (100 ms) of all jumps. Fatigued landings were performed with increased knee extension, and ankle plantar flexion at initial contact, as well as increased ankle range of motion during the impact phase. Fatigue also resulted in increased peak ankle power absorption and increased energy absorption at the ankle. This was accompanied by an approximately equal reduction in energy absorption at the knee. While the knee extensors were the muscle group primarily responsible for absorbing the impact, individuals compensated for increased knee extension when fatigued by an increased use of the ankle plantar flexors to help absorb the forces during impact. Thus, as fatigue set in and individuals landed with more extended lower extremities, they adopted a landing strategy that shifted a greater burden to the ankle for absorbing the kinetic energy of the impact.     

The effects of single-leg landing technique on ACL loading

Anterior Cruciate Ligament (ACL) injury is one of the most serious and costly injuries of the lower extremity, occurring more frequently in females than males. Injury prevention training programs have reported the ability to reduce non-contact ACL injury occurrence. These programs have also been shown to alter an athletes' lower extremity position at initial contact with the ground and throughout the deceleration phase of landing. The purpose of this study was to determine the influence of single-leg landing technique on ACL loading in recreationally active females. Participants were asked to perform "soft" and "stiff" drop landings. A series of musculoskeletal models were then used to estimate muscle, joint, and ACL forces. Dependent t-tests were conducted to investigate differences between the two landing techniques (p<0.05). Instructing participants to land 'softly' resulted in a significant decrease in peak ACL force (p=0.05), and a significant increase in hip and knee flexion both at initial contact (IC) and the time of peak ACL force (F(PACL)). These findings suggest that altering landing technique using simple verbal instruction may result in lower extremity alignment that decreases the resultant load on the ACL. Along with supporting the findings of reduced ACL force with alterations in sagittal plane landing mechanics in the current literature, the results of this study suggest that simple verbal instruction may reduce the ACL force experienced by athletes when landing.     

Effects of gender and foot-landing techniques on lower extremity kinematics during drop-jump landings

The purpose of this study was to assess kinematic lower extremity motion patterns (hip flexion, knee flexion, knee valgus, and ankle dorsiflexion) during various foot-landing techniques (self-preferred, forefoot, and rear foot) between genders. 3-D kinematics were collected on 50 (25 male and 25 female) college-age recreational athletes selected from a sample of convenience. Separate repeated-measures ANOVAs were used to analyze each variable at three time instants (initial contact, peak vertical ground reaction force, and maximum knee flexion angle). There were no significant differences found between genders at the three instants for each variable. At initial contact, the forefoot technique (35.79 degrees +/- 11.78 degrees ) resulted in significantly (p = .001) less hip flexion than did the self-preferred (41.25 degrees +/- 12.89 degrees ) and rear foot (43.15 degrees +/- 11.77 degrees ) techniques. At peak vertical ground reaction force, the rear foot technique (26.77 degrees +/- 9.49 degrees ) presented significantly lower (p = .001) knee flexion angles as compared with forefoot (58.77 degrees +/- 20.00 degrees ) and self-preferred (54.21 degrees +/- 23.78 degrees ) techniques. A significant difference for knee valgus angles (p = .001) was also found between landing techniques at peak vertical ground reaction force. The self-preferred (4.12 degrees +/- 7.51 degrees ) and forefoot (4.97 degrees +/- 7.90 degrees ) techniques presented greater knee varus angles as compared with the rear foot technique (0.08 degrees +/- 6.52 degrees ). The rear foot technique created more ankle dorsiflexion and less knee flexion than did the other techniques. The lack of gender differences can mean that lower extremity injuries (e.g., ACL tears) may not be related solely to gender but may instead be associated with the landing technique used and, consequently, the way each individual absorbs jump-landing energy.     

Lower extremity coupling parameters during locomotion and landings

During ballistic locomotion and landing activities, the lower extremity joints must function synchronously to dissipate the impact. The coupling of subtalar motion to tibial and knee rotation has been hypothesized to depend on the dynamic requirements of the task. This study was undertaken to look for differences in the coupling of 3-D foot and knee motions during walking, jogging, and landing from a jump. Twenty recreationally active young women with normal foot alignment (as assessed by a licensed physical therapist) were videotaped with high-speed cameras (250 Hz) during walking, jogging, hopping, and jumping trials. Coupling coefficients were compared among the four activities. The ratio of eversion to tibial rotation increased from the locomotion to the landing trials, indicating that with the increased loading demands of the activity, the requirements of foot motion increased. However, this increased motion was not proportionately translated into rotation of the tibia through the subtalar joint. Furthermore, the ratio of knee flexion to knee internal rotation increased significantly from the walking to landing trials. Together these findings suggest that femoral rotation may compensate for the increase in tibial rotation as the force-dissipating demands of the task increase. The relative unbalance among the magnitude of foot, tibial, and knee rotations observed with increasing task demands may have direct implications on clinical treatments aimed at reducing knee motion via controlling motion at the foot during landing tasks.     

Control of dynamic foot-ground interactions in male and female soccer athletes: Females exhibit reduced dexterity and higher limb stiffness during landing

Controlling dynamic interactions between the lower limb and ground is important for skilled locomotion and may influence injury risk in athletes. It is well known that female athletes sustain anterior cruciate ligament (ACL) tears at higher rates than male athletes, and exhibit lower extremity biomechanics thought to increase injury risk during sport maneuvers. The purpose of this study was to examine whether lower extremity dexterity (LED) – the ability to dynamically control endpoint force magnitude and direction as quantified by compressing an unstable spring with the lower limb at submaximal forces – is a potential contributing factor to the “at-risk” movement behavior exhibited by female athletes. We tested this hypothesis by comparing LED-test performance and single-limb drop jump biomechanics between 14 female and 14 male high school soccer players. We found that female athletes exhibited reduced LED-test performance (p=0.001) and higher limb stiffness during landing (p=0.008) calculated on average within 51 ms of foot contact. Females also exhibited higher coactivation at the ankle (p=0.001) and knee (p=0.02) before landing. No sex differences in sagittal plane joint angles and center of mass velocity at foot contact were observed. Collectively, our results raise the possibility that the higher leg stiffness observed in females during landing is an anticipatory behavior due in part to reduced lower extremity dexterity. The reduced lower extremity dexterity and compensatory stiffening strategy may contribute to the heightened risk of ACL injury in this population.     

A comparison between back squat exercise and vertical jump kinematics: implications for determining anterior cruciate ligament injury risk

Women are up to eight times more likely than men to suffer an anterior cruciate ligament (ACL) injury, and knee valgus is perhaps the most at-risk motion. Women have been shown to have more knee valgus than men in squatting movements and while landing. The purposes were to investigate whether a relationship exists between lower-extremity frontal plane motions in squatting and landing, whether gender differences exist, and whether squat or hip abduction strength relates to knee valgus while landing. Eleven collegiate Division III soccer players and 11 recreationally trained men were tested for maximal vertical jump height and for squat and hip abduction strength. On the second day of testing, subjects performed light (50% one repetition maximum) and heavy (85%) squat protocols and three landings from their maximal vertical jump height. Pearson's product-moment correlation coefficients and a 2 x 10 factorial analysis of variance with t-test post hoc comparisons (p 相似文献   

Increased hip adduction during running is associated with patellofemoral pain and differs between males and females: A case-control study

Patellofemoral pain is common amongst recreational runners and associated with altered running kinematics. However, it is currently unclear how sex may influence kinematic differences previously reported in runners with patellofemoral pain. This case-control study aimed to evaluate lower limb kinematics in males and females with and without patellofemoral pain during running. Lower limb 3D kinematics were assessed in 20 runners with patellofemoral pain (11 females, 9 males) and 20 asymptomatic runners (11 females, 9 males) during a 3 km treadmill run. Variables of interest included peak hip adduction, internal rotation and flexion angles; and peak knee flexion angle, given their previously reported association with patellofemoral pain. Age, height, mass, weekly run distance and step rate were not significantly different between groups. Mixed-sex runners with patellofemoral pain were found to run with a significantly greater peak hip adduction angle (mean difference = 4.9°, d = 0.91, 95% CI 1.4–8.2, p = 0.01) when compared to matched controls, but analyses for all other kinematic variables were non-significant. Females with patellofemoral pain ran with a significantly greater peak hip adduction angle compared to female controls (mean difference = 6.6°, p = 0.02, F = 3.41, 95% CI 0.4–12.8). Analyses for all other kinematic variables between groups (males and females with/without PFP) were non-significant. Differences in peak hip adduction between those with and without patellofemoral pain during running appear to be driven by females. This potentially highlights different kinematic treatment targets between males and females. Future research is encouraged to report lower limb kinematic variables in runners with patellofemoral pain separately for males and females.     

Comparison of lower limb kinetics,kinematics and muscle activation during drop jumping under shod and barefoot conditions

This study was to investigate the acute effects of wearing shoes on lower limb kinetics, kinematics and muscle activation during a drop jump. Eighteen healthy men performed a drop jump under barefoot and shod conditions. Vertical ground reaction force (GRF) was measured on a force plate during the contact phase of a drop jump, and GRF valuables were calculated for each condition. The angles of the knee and ankle joints, and the foot strike angle (the angle between the plantar surface of the foot and the ground during ground contact) as well as the electromyography of 7 muscles were measured. The shod condition showed a significant larger first peak GRF, longer time to first peak GRF from the initial ground contact and lower initial loading rate than the barefoot condition. The shod condition showed a significant larger ankle joint angle at initial ground contact, smaller knee joint angle between the second peak GRF and take-off as well as smaller foot strike angle at both initial ground contact and take-off than the barefoot condition. There were significant correlations between relative differences in ankle joint at the initial ground contact and relative differences in the initial loading rate. The muscle activity of all muscles during foot ground contact did not differ between two conditions; however, in the shod condition, muscle activation of 150 ms before foot ground contact was significantly higher in the rectus femoris, whereas it was lower in the biceps femoris and tibialis anterior muscles than the barefoot condition. These results indicate that wearing shoes alternates the GRF variables at initial ground contact, joint kinematics at the ground contact and muscle activation before foot ground contact during a drop jump, suggesting that the effects of wearing shoes on drop jump training differ from being barefoot.     

Effects of vertical loading on arch characteristics and intersegmental foot motions

The medial longitudinal arch plays a major role in determining lower extremity kinematics. Thus, it is necessary to understand the dynamics of the arch structure in response to load. The purpose of this study was to examine arch function in high- and low-arched feet during a vertical loading condition. Ten high- and ten low-arched females performed five trials in a sit-to-stand exercise. Ground reaction force (1200 Hz) and three-dimensional kinematics (240 Hz) were collected simultaneously. The high-and low-arched athletes had no differences in vertical deformation of the arch. High-arched participants were less everted than the low-arched athletes; furthermore, the high-arched athletes had smaller mid-forefoot eversion excursions. Differences between the high-arched and low-arched athletes occur through and motion at the mid-forefoot joint.     

Effect of arm swing direction on forward and backward jump performance

This study quantified and compared how the directional differences in arm swing affected mechanical and physiological parameters during forward and backward jumping. Seven subjects maximally performed three types of forward and backward squat jumps-no arm swing (FJ, BJ), forward arm swing (FJF, BJF), and backward arm swing (FJB, BJB) from a force platform. All performances were captured with a 3-D motion capture system. Electromyograms (EMGs) of the lower extremity muscles were obtained. Variables were calculated by combining kinematic and kinetic data. The jump displacement and center of mass velocity at take-off were significantly larger in FJF than in FJ or FJB and larger in BJB than in BJ or BJF, suggesting that the best performance was obtained by employing the same arm swing direction as a given jump direction. The total work by three lower and two upper extremity joints was significantly larger in FJF than in FJ or FJB and larger in BJB than in BJ or BJF. For the lower extremity joints, hip work was the greatest in FJF and BJB. The integrated EMG of the biceps femoris when the hip power was produced was significantly larger in FJF and BJB than under other conditions. These results suggest that if the arm swing direction is the same as a given jump direction, the activation level of the hip extensor is greater to counter large loads which make the hip joint flex during the push-off phase, which result in increased hip extension torque, power, and work.     

Modification of landing conditions at contact via flight

Weight-bearing tasks performed by humans consist of a series of phases with multiple objectives. Analysis of the relationship between control and dynamics during successive phases of the tasks is essential for improving performance without sustaining injury. Experimental evidence regarding foot landings suggests that the distribution of momentum among segments at contact influences stability during interaction with the landing surface. In this study, we hypothesized that modification of control in one subsystem, in our case shoulder torque, during the flight phase of an aerial task would enable the performer to maintain behavior of other subsystems (e.g.lower extremity kinematics) and initiate contact with momentum conditions consistent with successful task performance. To test this hypothesis, an experimentally validated multilink dynamic model that incorporated modifications in shoulder torque was used to simulate the flight phase dynamics of overrotated landings. The simulation results indicate that modification in shoulder torque during the flight phase enables gymnasts to maintain lower extremity kinematics and initiate contact with trunk angular velocities consistent with those observed during successful landings. These results suggest that modifications in the control logic of one subsystem may be sufficient for achieving both global and local task objectives of landing.     

Sex differences in the kinematics and neuromuscular control of landing: Biological,environmental and sociocultural factors

Potential sex differences in patterns of movement of recreational and competitive athletes were investigated in a systematic review of lower limb kinematics, muscle activation and stiffness during landing and hopping tasks. Little support for sex-specific lower limb kinematic patterns was found in 17 studies retrieved on landing and hopping. Ten studies retrieved on muscle activation during landing provided no support for sex-specific patterns. Four articles retrieved on leg stiffness established that absolute stiffness was lower in females, but differences in stiffness normalized to body mass were less clear. The wider literature indicates that a combination of biological, environmental and sociocultural constraints may shape movement patterns differently in females and males. Sociocultural factors differentially affect accumulated motor experience, practice opportunities and focus of attention in females, leading to differences in motor skill that confound the comparison of female and male movements. The findings of the review support the hypothesis that such sex differences in athletic performance are likely to diminish or disappear with increasing skill. In everyday movement tasks, however, where level of skill is a less meaningful dimension than in sport, differences in movement patterns observed between females and males point instead to the influence of subtle societal expectations on movement patterns.     

The effects of running in an exerted state on lower extremity kinematics and joint timing

Runners rarely run to the point of maximum fatigue or exhaustion. However, no studies have investigated how the level of exertion associated with a typical running session influences running mechanics. The purpose of this study was to investigate the effects that running in an exerted state had on the kinematics and joint timing within the lower extremity of uninjured, recreational runners. Twenty runners performed a prolonged treadmill run at a self-selected pace that best represented each runner’s typical training run. The run ended based on heart rate or perceived exertion levels that represented a typical training run. Kinematics and joint timing between the foot, knee, and hip were analyzed at the beginning and end of the run. Increases were primarily observed at the end of the run for the peak angles, excursions, and peak velocities of eversion, tibial internal rotation, and knee internal rotation. No differences were observed for knee flexion, hip internal rotation, or any joint timing relationship. Based on these results, runners demonstrated subtle changes in kinematics in the exerted state, most notably for eversion. However, runners were able to maintain joint timing throughout the leg, which may have been a function of the knee. Thus, uninjured runners normally experience small alterations in kinematics when running with typical levels of exertion. It remains unknown how higher levels of exertion influence kinematics with joint timing and the association with running injuries, or how populations with running injuries respond to typical levels of exertion.     

Effect of landing height on frontal plane kinematics, kinetics and energy dissipation at lower extremity joints

Lack of the necessary magnitude of energy dissipation by lower extremity joint muscles may be implicated in elevated impact stresses present during landing from greater heights. These increased stresses are experienced by supporting tissues like cartilage, ligaments and bones, thus aggravating injury risk. This study sought to investigate frontal plane kinematics, kinetics and energetics of lower extremity joints during landing from different heights. Eighteen male recreational athletes were instructed to perform drop-landing tasks from 0.3- to 0.6-m heights. Force plates and motion-capture system were used to capture ground reaction force and kinematics data, respectively. Joint moment was calculated using inverse dynamics. Joint power was computed as a product of joint moment and angular velocity. Work was defined as joint power integrated over time. Hip and knee joints delivered significantly greater joint power and eccentric work (p<0.05) than the ankle joint at both landing heights. Substantial increase (p<0.05) in eccentric work was noted at the hip joint in response to increasing landing height. Knee and hip joints acted as key contributors to total energy dissipation in the frontal plane with increase in peak ground reaction force (GRF). The hip joint was the top contributor to energy absorption, which indicated a hip-dominant strategy in the frontal plane in response to peak GRF during landing. Future studies should investigate joint motions that can maximize energy dissipation or reduce the need for energy dissipation in the frontal plane at the various joints, and to evaluate their effects on the attenuation of lower extremity injury risk during landing.     

Effect of foot orthotics on rearfoot and tibia joint coupling patterns and variability

The purpose of this study was to compare joint coupling patterns and variability of the rearfoot and tibia during running in subjects who were treated with two types of orthotic devices to that of controls. Eleven subjects with various lower extremity injuries were treated unsuccessfully with a standard orthotic, and then successfully with an inverted orthotic. Three-dimensional kinematic data were collected while subjects ran without orthoses and then in standard and inverted orthoses. Eleven healthy subjects ran without orthoses for comparison. The rearfoot inversion/eversion and tibial internal/external rotation joint coupling pattern and variability relationship was assessed using a vector coding technique. It was hypothesized that when the treated runners ran without orthotic devices, they would exhibit lower joint coupling angles and lower joint coupling variability compared to the controls. In addition, it was hypothesized that there would be no difference in the coupling angle or coupling variability between the standard and no orthotic conditions of the treated runners. Finally, it was hypothesized that coupling angle would decrease and variability would increase in the inverted versus the standard and non-orthotic conditions. No significant differences in joint coupling pattern or variability were observed between the treated and control subjects. In addition, no significant differences were noted between the orthotic conditions in the treated group. These results suggest that foot orthotic devices do not produce significant changes in rearfoot-tibial coupling. Therefore, the relief experienced with the inverted orthotic is likely due to factors other than alterations in this coupling.