Peak Hip Adduction Moment Research Articles

Comparison of Three-Dimensional Motion During Side-Step Cutting in Pediatric Athletes with Recent ACL Reconstruction and those with No ACL Surgical History

Objectives:This study assessed differences between pediatric athletes’ anterior cruciate ligament (ACL) reconstructed limb and non-reconstructed limb compared to limbs with no lower extremity surgical history during a side-step cut.Methods:28 limbs with an ACL reconstruction within the 12 months prior to testing (operative limbs), 28 contralateral limbs (non-operative limbs) and 56 limbs with no lower extremity surgical history (control limbs; 28 individuals) were included. Lower extremity kinematic and kinetic 3-dimensional data was recorded during the deceleration phase of a side-step cut. Outcomes were evaluated at initial foot contact and between initial foot contact and maximum knee flexion of the cutting limb. Differences between operative and non-operative limbs and control limbs were assessed using analysis of variance with Bonferroni post-hoc tests.Results:Operative limbs had higher peak hip adduction (-0.14° ± 7.3 vs. -6.1° ± 5.0, =0.01) and higher average external knee valgus moments (0.16 Nm/kg ± 0.50 vs. -0.21Nm/kg ± 0.58, p=0.02) compared to control limbs. In terms of shock absorption, operative limbs had lower peak ground reaction forces (23.2 N/kg ± 4.7 vs. 28.3 N/kg ± 5.8, p<0.0001) and peak ankle dorsiflexion (14.5° ± 7.5 vs. 20.0° ± 6.4, p=0.002) compared to control limbs with lower peak external knee flexor moments (1.4 Nm/kg ± 0.61 vs. 2.0 Nm/kg ± 0.63, p<0.0001) and less power absorption at the knee (0.38 Ws/kg ± 0.31 vs. 0.55Ws/kg ± 0.34, p=0.05) and ankle (0.43 Ws/kg ± 0.21 vs. 0.65 Ws/kg ± 0.41, p=0.01). Though non-operative limbs had less knee valgus (-1.0° ± 3.5 vs. 1.1° ± 3.3, p=0.04) at initial contact, they had higher peak knee valgus (3.6° ± 5.7 vs. 0.58° ± 4.1, p=0.04) and higher average external knee valgus moments (0.09 Nm/kg ±0.59 vs. -0.21Nm/kg ±0.58, p=0.06) compared to control limbs. Non-operative limbs also had less pelvic obliquity compared to control limbs (10.4° ± 5.8 vs. 14.6° ± 7.7, p=0.04). Lower peak ground reaction forces (24.5 N/kg ± 4.5 vs. 28.3 N/kg ± 5.8, p=0.005), increased power absorption at the hip (0.43 Ws/kg ± 0.48 vs. 0.15 Ws/kg ± 0.23, p=0.005), and decreased power absorption at the ankle (0.49 Ws/kg ± 0.23 vs. 0.65 Ws/kg ± 0.41, p=0.09) were seen in non-operative compared to control limbs.Conclusion:Limbs with ACL reconstruction exhibited poorer hip stability compared to control limbs. ACL reconstructed limbs also had less energy absorption at the knee and lower peak vertical ground reaction forces, likely reflecting an avoidance strategy when performing a cut using an ACL reconstructed limb. The uninjured, contralateral limbs of ACL reconstructed patients also demonstrated reduced ground reaction forces and altered neuromuscular control. These changes may reflect overall tentativeness in performing a cut but also suggest baseline suboptimal neuromuscular control that possibly lends insight into the increased risk of contralateral ACL tear seen in patients who have sustained an index ACL tear. It is also possible that the biomechanical strategies present on the operative side could be putting the non-operative limb at risk for injury. These findings support the need for ongoing research into rehabilitation protocols and return to sport timing and also support to existing injury prevention programs.

Side-step Cutting In Pediatric Athletes With Recent Acl Reconstruction Compared To Those With No Acl Surgical History

PURPOSE: This study assessed differences between pediatric athletes’ anterior cruciate ligament (ACL) reconstructed limb and non-reconstructed limb compared to limbs with no lower extremity surgical history during a side-step cut. METHODS: 28 limbs with an ACL reconstruction within the 12 months prior to testing (operative limbs), 28 contralateral limbs (non-operative limbs) and 56 limbs with no lower extremity surgical history (control limbs; 28 individuals) were evaluated. Kinematic and kinetic data was recorded during the deceleration phase of a cut. Outcomes were evaluated at initial foot contact and between initial foot contact and maximum knee flexion of the cutting limb. Differences were assessed using analysis of variance. RESULTS: Operative limbs had higher peak hip adduction (p=0.01) and average external knee valgus moments (p=0.02) compared to control limbs. In terms of shock absorption, operative limbs had lower peak ground reaction forces (p<0.0001) and peak ankle dorsiflexion (p=0.002) compared to control limbs with lower peak external knee flexor moments (p<0.0001) and less power absorption at the knee (p=0.05) and ankle (p=0.01). Though non-operative limbs had lower knee valgus (p=0.04) at initial contact, they had higher peak knee valgus (p=0.04) and average external knee valgus moments compared to control limbs. Non-operative limbs also had less pelvic obliquity compared to control limbs (p=0.04). Lower peak ground reaction forces (p=0.005), increased power absorption at the hip (p=0.005), and decreased power absorption at the ankle (p=0.09) were seen in non-operative compared to control limbs. CONCLUSIONS: Limbs with ACL reconstruction exhibited poorer hip stability compared to control limbs. ACL reconstructed limbs also had less energy absorption at the knee and lower peak vertical ground reaction forces, likely reflecting an avoidance strategy when performing a cut. The uninjured, contralateral limbs of ACL reconstructed patients also demonstrated reduced ground reaction forces and altered neuromuscular control. These changes may reflect overall tentativeness in performing a cut but also suggest suboptimal neuromuscular control that possibly lends insight into the increased risk of contralateral ACL tear in patients who have sustained an index ACL tear. These findings support the need for ongoing research into rehabilitation protocols and return to sport timing.

Evidence for joint moment asymmetry in healthy populations during gait

The purpose of this study was to determine the presence and prevalence of asymmetry in lower extremity joint moments within and across healthy populations during overground walking. Bilateral gait data from several studies performed at two institutions were pooled from 182 healthy, pain-free subjects. Four distinct populations were identified based on age, activity level and body mass index. Mean peak external joint moments were calculated from three to six trials of level overground walking at self-selected speed for each subject. Right and left limb moments were reclassified as “greater” or “lesser” moment for each subject to prevent obscuring absolute asymmetry due to averaging over positive and negative asymmetries across subjects. A clinically relevant asymmetry measure was calculated from the peak joint moments with an initial chosen cutoff value of 10%. Confidence intervals for the proportion of subjects with greater than 10% asymmetry between limbs were estimated based on the binomial distribution. We found a high amount of asymmetry between the limbs in healthy populations. More than half of our overall population exceeded 10% asymmetry in peak hip and knee flexion and adduction moments. Group medians exceeded 10% asymmetry for all variables in all populations. This may have important implications on gait evaluations, particularly clinical evaluations or research studies where asymmetry is used as an outcome. Additional research is necessary to determine acceptable levels of joint moment asymmetry during gait and to determine whether asymmetrical joint moments influence the development of symptomatic pathology or success of lower extremity rehabilitation.

Does Surgical Approach During Total Hip Arthroplasty Alter Gait Recovery During the First Year Following Surgery?

Multiple surgical approaches exist for total hip arthroplasty (THA). Each approach has risks and benefits in regard to complications and changes in postoperative gait. This study examined the effect of three surgical approaches on postoperative gait mechanics. Thirty patients completed a self-selected speed level walking gait assessment preoperatively, 6 weeks, and 1 year after surgery. We found no difference between approaches 1 year following surgery for any study variable. Several differences existed between time points independent of surgical approach. Significant improvement was found in sagittal and frontal plane hip ROM, peak hip extension and adduction angle and moment, the functional measures, walking speed, and the Harris Hip Score. This study suggests that postoperative gait changes are similar for the three analyzed surgical approaches.

The Effects of Floor Incline on Lower Extremity Biomechanics During Unilateral Landing From a Jump in Dancers

Retrospective studies have suggested that dancers performing on inclined ("raked") stages have increased injury risk. One study suggests that biomechanical differences exist between flat and inclined surfaces during bilateral landings; however, no studies have examined whether such differences exist during unilateral landings. In addition, little is known regarding potential gender differences in landing mechanics of dancers. Professional dancers (N = 41; 14 male, 27 female) performed unilateral drop jumps from a 30 cm platform onto flat and inclined surfaces while extremity joint angles and moments were identified and analyzed. There were significant joint angle and moment effects due to the inclined flooring. Women had significantly decreased peak ankle dorsiflexion and hip adduction moment compared with men. Findings of the current study suggest that unilateral landings on inclined stages create measurable changes in lower extremity biomechanical variables. These findings provide a preliminary biomechanical rationale for differences in injury rates found in observational studies of raked stages.

Does Increased Weight Alter Frontal Plane Mechanics In Healthy Controls?

Knee osteoarthritis (OA), which contributes to adult disability is strongly correlated with age, weight, and frontal plane biomechanical knee loading. While these factors are important, it is difficult to assess the independent effects of each due to their inherent interrelationships. In addition, there is an elevated incidence of knee OA in females which is associated with increased knee joint loading (knee adduction moment) compared to males. PURPOSE: To examine, during level walking, the relationship between increased weight and gender on frontal plane lower extremity gait mechanics that are related to knee OA progression. METHODS: Fifty-eight (30 male, 28 female) subjects were recruited for the study. All subjects underwent a standard level walking gait analysis in four different weight conditions: normal weight, 10% increased weight, 15% increased weight, and 20% increased weight. The weight conditions were randomized. Weight was distributed evenly in a vest with pockets for that purpose. Walking speed was controlled across conditions. A mixed factor ANOVA (gender x weight) was used to determine statistical significance (p < 0.05). RESULTS: No statistical interactions between gender and weight were observed. The increased weight conditions brought about incremental and statistically significant increases in peak rearfoot inversion moment (p=0.03), peak knee adduction moment during propulsion (p=0.001), plus peak hip adduction moment during weight acceptance (p=0.05) and propulsion (p<0.001). Males exhibited an elevated peak knee adduction moment during weight acceptance (p<0.001) and propulsion (p<0.001), peak knee adduction (p<0.001), peak hip adduction moment during propulsion (p<0.001), peak hip adduction (p<0.001), and hip adduction excursion (p=0.02) in comparison with the females. CONCLUSIONS: Increasing body weight increased lower extremity loading, however, the effect does not differ between males and females. Adding 15% and 20% more mass accounted for the majority of the differences when compared with no weight. Different findings might be observed in patients who have a mass distribution and weight that is more typical of chronic OA development.

Effects of Step Rate Manipulation on Joint Mechanics during Running

the objective of this study was to characterize the biomechanical effects of step rate modification during running on the hip, knee, and ankle joints so as to evaluate a potential strategy to reduce lower extremity loading and risk for injury. three-dimensional kinematics and kinetics were recorded from 45 healthy recreational runners during treadmill running at constant speed under various step rate conditions (preferred, ± 5%, and ± 10%). We tested our primary hypothesis that a reduction in energy absorption by the lower extremity joints during the loading response would occur, primarily at the knee, when step rate was increased. less mechanical energy was absorbed at the knee (P < 0.01) during the +5% and +10% step rate conditions, whereas the hip (P < 0.01) absorbed less energy during the +10% condition only. All joints displayed substantially (P < 0.01) more energy absorption when preferred step rate was reduced by 10%. Step length (P < 0.01), center of mass vertical excursion (P < 0.01), braking impulse (P < 0.01), and peak knee flexion angle (P < 0.01) were observed to decrease with increasing step rate. When step rate was increased 10% above preferred, peak hip adduction angle (P < 0.01) and peak hip adduction (P < 0.01) and internal rotation (P < 0.01) moments were found to decrease. we conclude that subtle increases in step rate can substantially reduce the loading to the hip and knee joints during running and may prove beneficial in the prevention and treatment of common running-related injuries.

Hip-Abductor Fatigue and Single-Leg Landing Mechanics in Women Athletes

Reduced hip-abductor strength and muscle activation may be associated with altered lower extremity mechanics, which are thought to increase the risk for anterior cruciate ligament injury. However, experimental evidence supporting this relationship is limited. To examine the changes in single-leg landing mechanics and gluteus medius recruitment that occur after a hip-abductor fatigue protocol. Descriptive laboratory study. Twenty physically active women (age = 21.0 ± 1.3 years). Participants were tested before (prefatigue) and after (postfatigue) a hip-abductor fatigue protocol consisting of repetitive side-lying hip abduction. Outcome measures included sagittal-plane and frontal-plane hip and knee kinematics at initial contact and at 60 milliseconds after initial contact during 5 single-leg landings from a height of 40 cm. Peak hip and knee sagittal-plane and frontal-plane joint moments during this time interval were also analyzed. Measures of gluteus medius activation, including latency, peak amplitude, and integrated signal, were recorded. A small (<1°) increase in hip-abduction angle at initial contact and a small (<1°) decrease in knee-abduction (valgus) angle at 60 milliseconds after contact were observed in the postfatigue landing condition. No other kinematic changes were noted for the knee or hip at initial contact or at 60 milliseconds after initial contact. Peak external knee-adduction moment decreased 27% and peak hip adduction moment decreased 24% during the postfatigue landing condition. Gluteus medius activation was delayed after the protocol, but no difference in peak or integrated signal was seen during the landing trials. Changes observed during single-leg landings after hip-abductor fatigue were not generally considered unfavorable to the integrity of the anterior cruciate ligament. Further work may be justified to study the role of hip-abductor activation in protecting the knee during landing.

Lower limb muscle strengthening does not change frontal plane moments in women with knee osteoarthritis: A randomized controlled trial

Background Osteoarthritis is a common musculo-skeletal problem accompanied with muscle weakness. Muscle weakness may be readily improved by resistance training. Greater muscle strength has been associated with a lower knee joint loading rate. Methods We conducted a single-blind randomized controlled trial of 54 female patients with osteoarthritis in at least one knee, according to the American College of Rheumatology clinical criteria. Patients were randomized into a 6-month high intensity progressive resistance training or a sham-exercise program. The primary outcomes were first peak knee and hip adduction moment measured using three-dimensional gait analysis at self-selected habitual and maximal speeds. Secondary outcomes were sagittal plane knee and hip moments, peak muscle strength, gait speed, and self-reported knee osteoarthritis symptoms measured by the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Findings Six months of high intensity resistance training did not change the first peak knee or hip adduction moment at either habitual or maximum walking speeds ( P > 0.413) compared to the sham-exercise. However, the second peak hip adduction moment ( P = 0.025) and WOMAC pain score ( P < 0.001) were reduced significantly in both groups over time, but there was no group effect. The changes in the second peak hip adduction moment were inversely related to the changes in the WOMAC pain score ( r = − 0.394, P = 0.009). Interpretations Muscle strength training in women with osteoarthritis, while effective for reducing osteoarthritis symptoms, appeared to operate through mechanisms other than improved knee or hip joint loading, as paradoxically, improved symptoms were related to decreases of hip adduction moment in late stance.

Frontal and Sagittal Plane Biomechanics During Drop Jump Landing in Boys Who Are Obese

To investigate the frontal and sagittal plane lower extremity biomechanics during drop jump landings in boys who were obese and boys who were of healthy weight. Twelve boys participated, 6 were considered as healthy weight (body mass index for age <85%, age 11.0 +/- 0.8 years), and 6 were considered as obese (body mass index for age >95%, age 12.1 +/- 0.7 years). Three-dimensional data were collected during landing from a drop jump. Group means were compared using Student t tests (alpha = 0.05). Significant differences were found in peak hip adduction moment, timing of peak dorsiflexion and knee flexion angles, and timing of peak knee extension and abduction moments. Boys who were obese exhibited significant differences in frontal and sagittal plane biomechanics when landing from a jump compared with healthy weight peers. These differences could place boys who are obese at greater risk for lower extremity injuries when they engage in jump-landing activities.

Biomechanical changes at the hip, knee, and ankle joints during gait are associated with knee osteoarthritis severity

Mechanical factors have been implicated in the progression of knee osteoarthritis (OA). Understanding how these factors change as the condition progresses would elucidate their role and help in developing interventions that could delay the progress of knee OA. In this cross-sectional study, we identified kinematic and kinetic variables at the hip, knee, and ankle joints that change between three clinically distinct levels of knee OA disease severity: asymptomatic, moderate OA, and severe OA. The severity level was based on a combined radiographic/symptomatic clinical decision for treatment with (severe) or without (moderate) total knee replacement surgery. Gait variables that changed between groups were categorized as: those that differed between the asymptomatic group and both OA groups, those that differed between the asymptomatic group and the severe OA group only, or those that changed progressively, that is, the asymptomatic differed from the moderate OA, and the moderate OA differed from the severe OA group. Changes seen in both OA subject groups compared to asymptomatic included increased mid-stance knee adduction moments, decreased peak knee flexion moments, decreased peak hip adduction moments, and decreased peak hip extension moments. Changes found only in the severe knee OA group included multiple kinematic and kinetic differences at the hip, knee, and ankle joints. Gait differences that progressed with OA severity included decreased stance phase knee flexion angles, decreased early stance knee extension moments, decreased peak stance phase hip internal rotation moments, and decreased peak ankle dorsiflexion moments.

The Evaluation of Patellofemoral Pain in the Clinic

Static measures taken in the clinic are commonly used to infer the cause and treatment of patients with patellofemoral pain (PFP). Functional joint loading parameters taken from a three-dimensional gait analysis also provide useful data to investigate potential mechanisms of lower limb injury, although this takes time, expertise, and expensive equipment. It would be useful for a clinician to assess dynamic joint loading from some simple measures taken in the clinic. Particular focus is given to the hip muscles due to their ability to control femoral rotation and valgus posture at the knee. PURPOSE: To determine if routine clinical measures predict dynamic joint loading response during gait in patients with PFP. METHODS: Gait analysis data and clinical measurements were obtained from 24 subjects with PFP (10 males, 14 females). Subjects walked at a self-selected pace and data were averaged across five trials. Three dimensional kinematics and kinetics were determined using an 8-camera motion analysis system, Bertec force plate, and a standard lower limb marker set. The following parameters were obtained; peak hip adduction moment, hip adduction angle, knee adduction moment, and knee flexion moment. An experienced clinician then took the following clinical measures for each subject; Q-angle, absolute hip abduction strength, hip internal rotation range of motion, iliotibial band tightness, and thigh circumference. A Pearson correlation coefficient was used to compare individual gait variables with clinical measures. A multiple linear regression was also used to determine the ability of the clinical measures to predict the gait variables. RESULTS: Decreased hip abductor strength was associated with decreased hip adductor moments. (R2 = 0.196, p = 0.03). Increased Q-angle was associated with increased peak hip adduction angle (R2 = 0.309, p = 0.005). Agreater ratio of hip internal/ external rotation (IE ratio) was associated with increased hip adduction moments during gait (R2 = 0.179, p = 0.04). Multiple regression using factors hip abductor strength, hip IE ratio, and Q-angle improved the predictions of peak hip adduction moment to 37%. The Q angle and absolute hip abductor strength combined to predict 30% of the knee peak adduction moment. CONCLUSION: In the evaluation of PFP, Q-angle, hip strength, and hip IE ratio were simple clinical measures that were predictive of relevant lower extremity moments and angles during active gait. Supported by Veterans Affairs Rehabilitation R&D (#A2592R), NIH (EB005790-01), and Stanford Regenerative Medicine (1R-90DK071508).

The effects of walking speed on obstacle crossing in healthy young and healthy older adults

The effects of walking speed and age on the peak external moments generated about the joints of the trailing limb during stance just prior to stepping over an obstacle and on the kinematics of the trailing limb when crossing the obstacle were investigated in 10 healthy young adults (YA) and 10 healthy older adults (OA). The peak hip and knee adduction moments in OA were 21–43% greater than those in YA ( p⩽0.046). The angular velocity of hip flexion from toe-off to when the toe was over the obstacle in OA was 20% less than that in YA ( p=0.048). Eight external peak moments about the hip, knee, or ankle increased significantly with speed in both groups ( p⩽0.01); the largest in the sagittal plane was 62% for knee flexion ( p⩽0.0001). Toe–obstacle clearance was not affected. Trailing foot placement was affected by speed, but not by age. Speed produced a small change (∼1°) in knee abduction–adduction, the only joint angle affected ( p=0.022). The greater magnitudes of hip and ankle adduction moments occurring in the trailing limb of OA place larger demands on the hip and ankle abductors of the trailing limb to maintain dynamic balance when stepping over the obstacle with the leading limb.