Frontal plane kinematics predict three-dimensional hip adduction during running

ObjectivesTo investigate if frontal plane kinematics are predictive of three dimensional (3D) hip adduction and hip internal rotation during running.Study designCross-sectional.SettingBiomechanics laboratory.ParticipantsThirty healthy male runners aged 18–45 years.Main outcome measuresTwo dimensional (2D) angles in the frontal plane (peak pelvic obliquity, peak hip adduction, peak femoral valgus, peak knee valgus and peak tibial valgus) and 3D hip adduction and hip internal rotation during stance phase of running were obtained.ResultsLinear regression modelling revealed that peak 2D pelvic obliquity (a drop towards the contralateral leg) and peak femoral valgus significantly predicted 88% of the variance in peak 3D hip adduction (p < 0.001). Frontal plane kinematics however, were not predictive of peak hip internal rotation in 3D (p > 0.05).ConclusionsFrontal plane kinematics, specifically contralateral pelvic drop and femoral valgus, predicted the vast majority of the variance in 3D hip adduction during the stance phase of running. This indicates that 2D video may have potential as a clinically feasible proxy for measurement of peak 3D hip adduction – a risk factor for patellofemoral pain.     

The effect of pain on hip and knee kinematics during running in females with chronic patellofemoral pain

PurposeDespite the growing recognition of the role of abnormal hip and knee mechanics in patellofemoral pain (PFP), few studies have assessed if or how these mechanics change when the person experiences pain while running. Therefore, the purpose of this study was to determine if the development of pain while running resulted in altered hip and knee kinematics in female runners with PFP as compared to healthy female runners.MethodsThirty female runners (15 PFP, 15 controls) participated in an instrumented gait analysis while running for 30 min at a self-selected pace. Pain and fatigue were recorded every minute while participants ran. Variables of interest included peak hip adduction, hip internal rotation, knee abduction, knee external rotation, pain, and fatigue.ResultsThere were significant group by pain interactions for hip adduction (p < 0.01) and hip internal rotation (p < 0.01). The healthy group, who did not develop pain had significant increases in both motions compared to the PFP group, who did develop pain. There was also a trend toward less knee external rotation in the PFP group in presence of pain (p = 0.059). No differences were found for knee abduction (p = 0.32). A group main effect was found for hip internal rotation (p = 0.008) in which the PFP group had significantly larger values.ConclusionRunners with PFP did not alter their hip mechanics over the course of the run. This may have resulted in repetitive stress to the same aspect of the patellofemoral joint and contributed to the initial development of pain. However, the PFP group did attempt to make a compensation once in pain by reducing knee external rotation.     

Relationship among maximum hip isometric strength,hip kinematics,and peak gluteal muscle force during running

ObjectiveTo determine if there is a relationship among isometric hip strength, hip kinematics, and peak gluteal muscle forces in cross-country runners during running.DesignCross Sectional.SettingUniversity Biomechanics Laboratory.ParticipantsForty-six NCAA Division III collegiate cross-country runners (18 males, 28 females).Main outcome measuresPearson correlation coefficients were used to describe relationships among isometric hip strength, hip kinematics, and peak gluteal muscle forces during the stance phase of running. Strength of correlations were interpreted as little to no relationship (r < 0.25), fair relationship (0.25 ≤ r < 0.5), moderate relationship (0.5 ≤ r < 0.75), and strong relationship (r ≥ 0.75). Correlations were considered significant if p < 0.05.ResultsLittle to no relationships were found among isometric hip strength and gluteal muscle forces during running (r < 0.25). A fair relationship was present between prone external rotation isometric hip strength and peak hip adduction (0.25 < r < 0.5). Little to no relationship was shown between gluteus medius force and hip internal rotation. Moderate relationships were present among peak gluteus medius and minimus muscle forces and peak hip adduction (0.5 < r < 0.75).ConclusionIsometric hip strength does not appear to be related to gluteal muscle forces and hip kinematics during the stance phase of running while gluteal muscle force was moderately related to hip adduction. Factors other than strength may be related to muscle force production and hip kinematics during running.     

Do hip strength,flexibility and running biomechanics predict dynamic valgus in female recreational runners?

BackgoundDynamic valgus has been the focus of many studies to identify its association to an increased risk of running-related injuries. However, it is not known which physical and biomechanical variables are associated with this movement dysfunction. Research question: This study aimed to test the correlation between strength, flexibility and biomechanical variables and dynamic valgus in female runners.MethodsTwenty-nine healthy females ran on a treadmill at 2.92 m/s and performed strength, range of motion and endurance tests. Pelvic, hip and ankle kinematics were measured with a 3D motion analysis system. Six multiple linear regression models were used to identify the ability of physical and biomechanical variables to predict excursion and peak of contralateral pelvic drop, hip adduction and internal rotation.ResultsContralateral pelvic drop and hip adduction were positively correlated to ankle eversion and step cadence. Hip internal rotation had a negative correlation with ankle eversion. Despite significance, predictor variables explained less than 30% of dynamic valgus variance during running. No interest variable had significant correlation with the hip strength and hip and ankle passive range of motion.SignificanceThe results showed that distal joint kinematics and spatiotemporal variables should be considered during biomechanical running analysis to identify their possible relationship with joint overload caused by dynamic valgus. Caution should be taken when linking hip disorders during running to posterolateral hip strength and stiffness, core endurance, and ankle dorsiflexion range of motion since no correlation occurred amongstthese variables in this sample of female runners.     

Influence of hamstring flexibility on running kinematics in adolescent long-distance runners

BackgroundStudies have found no or minimal differences in running kinematics between flexible and inflexible adult runners. The interaction between hamstring flexibility and running kinematics has not been reported in adolescent long-distance runners.Research questionDoes hamstring flexibility influence running kinematics in adolescent long-distance runners?MethodsAdolescent long-distance runners (n = 140, ages 9–19) were enrolled in our cross-sectional study. Hamstring flexibility was assessed with the forward bending Beighton task. Runners were categorized if they tested positive or negative on the forward bending task. Participants ran at a comfortable self-selected speed on a treadmill. Runners who tested positive on the forward bending task (n = 17) were matched with runners who tested negative on the task (n = 17) according to sex, physical maturation, and running speed. Statistical parametric mapping compared trunk, pelvis, hip, and knee kinematic waveforms throughout the gait cycle and independent sample t tests compared temporal-spatial parameters between the groups.ResultsRunners who tested positive on the forward bending task demonstrated significantly greater anterior pelvic tilt during stance (average difference = 4.8° ± 0.4°, p < .001) and swing (average difference = 4.3° ± 0.2°, p < .01) compared to runners who tested negative on the forward bending task. No significant differences were found between groups for the remaining kinematic waveforms or for any temporal-spatial parameters (p > .05).SignificanceThis is the first study to report the interaction between hamstring flexibility and running kinematics in adolescent long-distance runners. The greater anterior pelvic tilt demonstrated by runners with greater hamstring flexibility may place more eccentric demands on the hamstring musculature. However, as there were no other differences in joint kinematics or temporal-spatial parameters between groups, greater hamstring flexibility does not appear to have a significant interaction with running kinematics when running at sub-maximal speeds. Our results suggest hamstring flexibility does not predispose adolescent long-distance runners to sub-optimal segment positions associated with running-related injuries.     

The effect of changing mediolateral center of pressure on rearfoot eversion during treadmill running

IntroductionAtypical rearfoot eversion is an important kinematic risk factor in running-related injuries. Prominent interventions for atypical rearfoot eversion include foot orthoses, footwear, and taping, yet a running gait retraining is lacking. Therefore, the aim was to investigate the effects of changing mediolateral center of pressure (COP) on rearfoot eversion, subtalar pronation, medial longitudinal arch angle (MLAA), hip kinematics and vertical ground reaction force (vGRF).MethodsFifteen healthy female runners underwent gait retraining under three conditions. Participants were instructed to run normally, on the lateral (COP lateral) and medial (COP medial) side of the foot. Foot progression angle (FPA) was controlled using real-time visual feedback. 3D measurements of rearfoot eversion, subtalar pronation, MLAA, FPA, hip kinematics, vGRF and COP were analyzed. A repeated-measures ANOVA followed by pairwise comparisons was used to analyze changes in outcome between three conditions. Data were also analyzed using statistic parameter mapping.ResultsRunning on the lateral side of the foot compared to normal running and running on the medial side of the foot reduced peak rearfoot eversion (mean difference (MD) with normal 3.3°, p < 0.001, MD with COP medial 6°, p < 0.001), peak pronation (MD with normal 5°, p < 0.001, MD with COP medial 9.6°, p=<0.001), peak MLAA (MD with normal 2.3°, p < 0.001, MD with COP medial 4.1°, p < 0.001), peak hip internal rotation (MD with normal 1.8°, p < 0.001), and peak hip adduction (MD with normal running 1°, p = 0.011). Running on the medial side of the foot significantly increased peak rearfoot eversion, pronation and MLAA compared to normal running.SignificanceThis study demonstrated that COP translation along the mediolateral foot axis significantly influences rearfoot eversion, MLAA, and subtalar pronation during running. Running with either more lateral or medial COP reduced or increased peak rearfoot eversion, peak subtalar pronation, and peak MLAA, respectively, compared to normal running. These results might use as a basis to help clinicians and researchers prescribe running gait retraining by changing mediolateral COP for runners with atypical rearfoot eversion or MLAA.     

Effects of medially wedged insoles on the biomechanics of the lower limbs of runners with excessive foot pronation and foot varus alignment

BackgroundExcessive foot pronation during running in individuals with foot varus alignment may be reduced by medially wedged insoles.Research questionThis study investigated the effects of a medially wedged insole at the forefoot and at the rearfoot on the lower limbs angles and internal moments of runners with excessive foot pronation and foot varus alignment.MethodsKinematic and kinetic data of 19 runners (11 females and 8 males) were collected while they ran wearing flat (control condition) and medially wedged insoles (insole condition). Both insoles had arch support. We used principal component analysis for data reduction and dependent t-test to compare differences between conditions.ResultsThe insole condition reduced ankle eversion (p = 0.003; effect size = 0.63); reduced knee range of motion in the transverse plane (p = 0.012; effect size = 0.55); increased knee range of motion in the frontal plane in early stance and had earlier knee adduction peak (p = 0.018; effect size = 0.52); reduced hip range of motion in the transverse plane (p = 0.031; effect size = 0.48); reduced hip adduction (p = 0.024; effect size = 0.50); reduced ankle inversion moment (p = 0.012; effect size = 0.55); and increased the difference between the knee internal rotation moment in early stance and midstance (p = 0.012; effect size = 0.55).SignificanceInsoles with 7˚ medial wedges at the forefoot and rearfoot are able to modify motion and moments patterns that are related to lower limb injuries in runners with increased foot pronation and foot varus alignment with some non-desired effects on the knee motion in the frontal plane.     

Are hip and knee kinematics and training load characteristics relate to pain intensity and physical function level in runners with Patellofemoral Pain?

BackgroundPatellofemoral pain (PFP) is the most common running-related injury. Altered hip and knee kinematics and increases in weekly distance and running pace are often associated with PFP development and exacerbation.Research questionAre altered movements and training load characteristics (weekly distance and running pace) relate to pain intensity or physical function level in runners with PFP?MethodsForty recreational runners with PFP (20 males and 20 females) participated in this cross-sectional observational study. Three-dimensional hip and knee kinematics were quantified during the stance phase of running. Weekly distance was defined as the average weekly kilometers of running and running pace as the average pace of the activity measured as minutes per kilometer. A visual analogue scale was used to evaluate worst knee pain during the last week. The anterior knee pain scale (AKPS) was used to evaluate knee functional score. A Pearson correlation matrix was used to investigate the association between each dependent variable (worst pain in the last week and AKPS score) and the independent variables (knee and hip kinematics, weekly distance and running pace).ResultsThere was no significantly correlation between kinematic variables, pain and functional score for both males and females separately and combined. Weekly distance (km/week) was found to positively correlate to pain intensity (r = 0.452; p < 0.05) in females with PFP. A simple linear regression revealed that weekly distance was significant predictor emerged of pain in females with PFP. Females exhibited significantly greater peak hip adduction and hip adduction ROM than the males and males had significantly greater running pace compared to females.SignificanceWeekly distance should be considered in the clinical context during rehabilitation of PFP in females runners aiming at pain reduction.     

Sex and limb differences during a single-leg cut with body borne load

BackgroundMilitary personnel don body borne loads that produce maladaptive lower limb biomechanics, increasing risk of musculoskeletal injury during common training tasks. Female personnel have over twice the injury risk as males, but it is unknown if a sex dimorphism in lower limb biomechanics exists during common training-related tasks.Research QuestionTo determine whether lower limb biomechanics exhibited during a single-leg cut with military body borne loads differ between sexes.MethodsSixteen females and 20 males had lower limb biomechanics quantified during five single-leg cuts off each limb with four loads (20, 25, 30 and 35 kg). Each cut required participants run 4 m/s, before planting their foot on a force platform and cut 45° towards the opposite limb. Lower limb biomechanics related to musculoskeletal injury were submitted to a repeated measures ANOVA to test for main and interaction effects of load, sex, and limb.ResultsDuring the cut, load increased peak proximal anterior tibial shear force (p < 0.001) and peak hip flexion (p = 0.010) and knee abduction (p = 0.045) moments, but decreased peak knee flexion angle (p = 0.032). Females exhibited greater peak proximal anterior tibial shear (p = 0.014), and peak hip adduction (p < 0.001) and knee external rotation (p = 0.001) moment than males. Dominant limb exhibited larger peak hip adduction (p = 0.002); whereas, the non-dominant limb exhibited greater peak hip internal (p = 0.002) and knee external (p = 0.007) rotation moments. Only the non-dominant limb increased peak knee abduction moment (p = 0.001) with additional load.SignificanceDuring the cut, adding body borne load produced maladaptive biomechanics that may increase knee musculoskeletal injury risk. Load increased peak proximal tibial shear and potential strain of knee’s soft-tissues. Females exhibited a sex dimorphism in lower limb biomechanics that may further elevate their injury risk. Both limbs exhibited biomechanics that may increase injury risk, but only the non-dominant limb further increased injury risk with load.     

Do novice runners have weak hips and bad running form?

First, we sought to better understand the predisposition of novice female runners to injury by identifying potential differences in running mechanics and strength between experienced female runners and active novice runners. Secondly, we aimed to assess the relationship between hip and trunk strength with non-sagittal hip kinematics during running. Two female populations were recruited: 19 healthy experienced runners and 19 healthy active novice runners. Strength measurements of the hip abductors and external rotators were measured using a hand held dynamometer while trunk endurance was assessed via a side-plank. Next, an instrumented gait analysis was performed while each participant ran at 3.3 m/s. Group comparisons were made using an independent t-test to identify differences in the impact peak, loading rate, peak non-sagittal hip joint angles, trunk endurance, and hip strength. Pearson's correlation coefficients were calculated between hip kinematics and strength measurements. There were no statistically significant differences in impact peak, loading rate, peak non-sagittal hip kinematics, or strength. However, the novice runners did show a clinically meaningful trend toward increased peak hip internal rotation by 3.8° (effect size 0.520). A decrease in trunk side-plank endurance was associated with an increased peak hip internal rotation angle (r = −0.357, p = 0.03), whereas isometric strength was not related to kinematics. Programs aiming to prevent injuries in novice runners should target trunk performance and possibly hip neuromuscular control, rather than hip strength.     

Effects of load carriage on biomechanical variables associated with tibial stress fractures in running

BackgroundMilitary personnel are required to run while carrying heavy body-borne loads, which is suggested to increase their risk of tibial stress fracture. Research has retrospectively identified biomechanical variables associated with a history of tibial stress fracture in runners, however, the effect that load carriage has on these variables remains unknown.Research questionWhat are the effects of load carriage on running biomechanical variables associated with a history of tibial stress fracture?MethodsTwenty-one women ran at 3.0 m/s on an instrumented treadmill in four load carriage conditions: 0, 4.5, 11.3, and 22.7 kg. Motion capture and ground reaction force data were collected. Dependent variables included average loading rate, peak absolute free moment, peak hip adduction, peak rearfoot eversion, and stride frequency. Linear mixed models were used to asses the effect of load carriage and body mass on dependent variables.ResultsA load x body mass interaction was observed for stride frequency only (p = 0.017). Stride frequency increased with load carriage of 22.7-kg, but lighter participants illustrated a greater change than heavier participants. Average loading rate (p < 0.001) and peak free moment (p = 0.015) were greater in the 22.7-kg condition, while peak rearfoot eversion (p ≤ 0.023) was greater in the 11.3- and 22.7-kg conditions, compared to the unloaded condition. Load carriage did not affect peak hip adduction (p = 0.67).SignificanceParticipants adapted to heavy load carriage by increasing stride frequency. This was especially evident in lighter participants who increased stride frequency to a greater extent than heavier participants. Despite this adaptation, running with load carriage of ≥11.3-kg increased variables associated with a history of tibial stress fracture, which may be indicative of elevated stress fracture risk. However, the lack of concomitant change amongst variables as a function of load carriage may highlight the difficulty in assessing injury risk from a single measure of running biomechanics.     

Maintaining motivation and health among recreational runners: Panel study of factors associated with self-rated performance outcomes at competitions

ObjectivesTo investigate health-related factors associated with self-rated race performance outcomes among recreational long-distance runners.DesignPanel study.MethodsData were collected from runners one month before and after a community-level race event including distances from 8 to 42.2 km. The primary outcome measure was self-rated race performance outcome. The explanatory variables represented health complaints suffered during the build-up year, the pre-race month, and the race and among full marathon runners predicted objective performance outcome (mean pace equal to training pace or faster). Multiple logistic regression was used to determine factors associated with the self-rated performance outcome.ResultsTwo-hundred forty-five runners (29%) provided complete data sets. Seventy-four percent of the runners reached their desired race performance outcome. Achievement of the performance outcome was more likely when having avoided illness during the build-up and pre-race periods (OR = 3.8; 95% CI:1.8–8.0, p < 0.001), having avoided per-race injury (OR=3.0; 95% CI:1.2–7.4, p = 0.02) and avoided per-race illness (OR = 4.1; 95% CI:1.3–15, p = 0.020). Having obtained the self-rated performance outcome was also associated with running a shorter distance (OR=3.6; 95% CI: 1.7–8.0, p = 0.001) and being younger than 50 years of age (OR = 2.4; 95% CI:1.1–5.3–8.3, p = 0.03). Having met the predicted objective performance outcome predisposed marathon runners to also obtain the self-rated performance outcome (OR = 4.7, 95% CI: 1.5–16, p < 0.01).ConclusionsHaving avoided illness during build-up and pre-race was positively associated with self-rated race performance outcome among recreational runners. Adjusting the desired performance outcomes with regard to recent illness and age may help recreational runners to more often achieve their goals and thereby prevent them from leaving the sport.     

The effects of increased forward trunk lean during stair ascent on hip adduction and internal rotation in asymptomatic females

BackgroundIncreased hip adduction and internal rotation can lead to excessive patellofemoral joint stress and contribute to patellofemoral pain development. The gluteus maximus acts as a hip extensor, abductor, and external rotator. Improving hip extensor use by increasing one’s forward trunk lean in the sagittal plane may improve frontal and transverse plane hip kinematics during stair ascent.Research questionDoes increasing forward trunk lean during stair ascent affect peak hip adduction and internal rotation?MethodsTwenty asymptomatic females performed five stair ascent trials (96 steps/min) on an instrumented stair using their self-selected and forward trunk lean postures. Three-dimensional kinematics (200 Hz) and kinetics (2000 Hz) were recorded during the stance phase of stair ascent. Biomechanical dependent variables were calculated during the stance phase of stair ascent and included peak forward trunk lean, hip flexion, hip adduction, hip internal rotation angles, and the average hip extensor moment.ResultsDuring the forward trunk lean condition, decreases were observed for peak hip adduction (MD = 2.8˚; 95% CI = 1.9, 3.8; p < 0.001) and peak hip internal rotation (MD = 1.1˚; 95% CI = 0.1, 2.2; p = 0.04). In contrast, increases were observed during the forward trunk lean condition for the peak forward trunk lean angle (MD = −34.7˚; 95% CI = −39.1, −30.3; p < 0.001), average hip extensor moment (MD = −0.5 N·m/kg; 95% CI = −0.5, −0.4; p < 0.001), and stance time duration (MD = −0.02 s; 95% CI = −0.04, 0.00; p = 0.017).SignificanceIncreasing forward trunk lean and hip extensor use during stair ascent decreased peak hip adduction and internal rotation in asymptomatic females. Future studies should examine the effects of increasing forward trunk lean on hip kinematics, self-reported pain, and function in individuals with patellofemoral pain.     

Effect of pelvic,hip, and knee position on ankle joint range of motion

ObjectiveTo determine if pelvic posture, hip, and knee positions influence range of motion about the ankle joint.Study designQuasi-experimental repeated measures.SettingBiomechanics laboratory in a university setting.ParticipantsEleven men and six women free of ankle joint trauma.Main outcome measuresRange of motion about the ankle joint.ResultsANOVA revealed a significant difference for position main effect on ankle joint range of motion (p=0.01). Post-hoc tests revealed that ankle joint range of motion significantly decreased as participants moved from flexion (i.e., 90° hip and 90° knee), to supine, and to long sitting (47.3°, 38.8°, and 16.4°; p<0.05). No significant differences were revealed for pelvic posture (p=0.64).ConclusionsThese findings indicate that pelvic posture may not influence ankle joint range of motion regardless of hip and knee joint positions. However, the combination of hip flexion and knee extension (i.e., long sitting) produces the greatest deficits in ankle joint range of motion.     

Test-retest reliability of two-dimensional video analysis during running

ObjectivesTo examine test-retest reliability of two-dimensional measured frontal and sagittal plane kinematics during running, and to determine how many steps to include to reach and maintain a stable mean.DesignReliability study.SettingResearch laboratory.ParticipantsTwenty-one recreational runners.Main outcome measuresLateral trunk position, contralateral pelvic drop, femoral adduction, hip adduction, knee flexion and ankle dorsiflexion during midstance, and foot and tibia inclination at initial contact were measured with two-dimensional video analysis during running for 10 consecutive steps for both legs. All participants were tested twice one week apart. A sequential estimation method was used to determine the number of steps needed to reach a stable mean. Intraclass correlation coefficients (ICC) and smallest detectable differences (SDD) were calculated.ResultsThe minimal number of steps was 6.3 ± 0.3. Lateral trunk position, femoral adduction and foot inclination showed excellent reliability (ICC 0.90–0.99; SDD 1.3°–2.3°). Tibia inclination and ankle dorsiflexion showed good to excellent reliability (ICC 0.73–0.92; SDD 2.2°–4.8°). Hip adduction and knee flexion showed good reliability (ICC 0.82–0.89; SDD 2.3°–3.8°). Contralateral pelvic drop showed moderate to good reliability (ICC 0.59–0.77; SDD 2.7°–2.8°).ConclusionTwo-dimensional video analysis is reliable to assess running kinematics on different days. The mean of at least 7 steps should be included.     

Runners with patellofemoral pain have altered biomechanics which targeted interventions can modify: A systematic review and meta-analysis

Patellofemoral pain (PFP) is the most prevalent running pathology and associated with multi-level biomechanical factors. This systematic review aims to guide treatment and prevention of PFP by synthesising prospective, observational and intervention studies that measure clinical and biomechanical outcomes in symptomatic running populations. Medline, Web of Science and CINAHL were searched from inception to April 2015 for prospective, case-control or intervention studies in running-related PFP cohorts. Study methodological quality was scored by two independent raters using the modified Downs and Black or PEDro scales, with meta-analysis performed where appropriate. 28 studies were included. Very limited evidence indicates that increased peak hip adduction is a risk factor for PFP in female runners, supported by moderate evidence of a relationship between PFP and increased peak hip adduction, internal rotation and contralateral pelvic drop, as well as reduced peak hip flexion. Limited evidence was also identified that altered peak force and time to peak at foot level is a risk factor for PFP development. Limited evidence from intervention studies indicates that both running retraining and proximal strengthening exercise lead to favourable outcomes in both pain and function, but only running retraining significantly reduces peak hip adduction, suggesting a possible kinematic mechanism. Put together, these findings highlight limited but coherent evidence of altered biomechanics which interventions can alter with resultant symptom change in females with PFP. There is a clear need for high quality prospective studies of intervention efficacy with measurement of explanatory mechanisms.     

Prediction of mild anatomical leg length discrepancy based on gait kinematics and linear regression model

BackgoundLeg length discrepancy (LLD) can be related to different pathologies, due to an inadequate distribution of mechanical loads, as well as gait kinematics asymmetries resulted from LLD.Research questionTo validate a model to predict anatomical LLD (ALLD) based on gait kinematics.MethodsGait of 39 participants with different lower limb pathologies and mild discrepancy were collected. Pelvic, hip, knee and ankle kinematics were measured with a 3D motion analysis system and ALLD, femur discrepancy (FD) and tibia discrepancy (TD) were measured by a computerized digital radiograph. Three multiple linear regression models were used to identify the ability of kinematic variables to predict ALLD (model 1), FD (model 2) and TD (model 3).ResultsDifference between peak knee and hip flexion of the long and short lower limb was selected by models 1 (p < 0.001) and 2 (p < 0.001). Hip adduction was selected as a predictor only by model 1 (p = 0.05). Peak pelvic obliquity and ankle dorsiflexion were not selected by any model and model 3 did not retain any dependent variable (p > 0.05). Regression models predicted mild ALLD with moderate accuracy based on hip and knee kinematics during gait, but not ankle strategies. Excessive hip flexion of the longer limb possibly occurs to reduce the limb to equalize the LLD, and discrepancies of the femur and tibia affects gait cycle in a different way.SignificanceThis study showed that kinematic variables during gait could be used as a screening tool to identify patients with ALLD, reducing unnecessary x-ray exposure and assisting rehabilitation programs.     

The effects of foot orthosis and low-dye tape on lower limb joint angles and moments during running in individuals with pes planus

BackgroundPes Planus or Flat feet is one of the most common lower limb abnormalities. When runners with this abnormality participate in recreational running, interventional therapies could help in pain alleviation and enhance performance. To determine the most effective treatment, however, a biomechanical examination of the effects of each treatment modality is required.Research questionThe aim of the present study was to investigate the effects of Foot Orthoses (FOs) and Low-Dye Tape (LDT) on lower limb joint angles and moments during running in individuals with pes planus.Methodskinematic and kinetic data of 20 young people with pes planus were measured during running in three conditions: (1) SHOD (2) with shoes and FOs (3) with shoes and LDT. One-way repeated measure ANOVA was used to investigate the impacts of the FOs and LDT on the lower limb joint angles and moments throughout the stance phase of the running cycle.ResultsThe results showed that FOs reduced ankle eversion compared to SHOD and LDT (P < 0.001) and decreased the dorsiflexion angle (P = 0.005) and the plantarflexor moment compared to the SHOD (P < 0.001). FOs increased knee adduction angle (P = 0.021) and knee external rotator moment (P < 0.001) compared to both conditions and increased knee extensor and abductor moments compared to SHOD (P < 0.001). At the hip joint, FOs only increased hip external rotation compared with the LDT condition (P = 0.031); and LDT increased hip extensor moment compared to SHOD and FOs (P = 0.037) and also increased hip adduction angle compared to SHOD (P = 0.037).SignificanceFOs with a medial wedge appears to increase the external knee adduction moment and knee adduction angles, which are risk factors for the development and progression of knee osteoarthritis. Further, usage of FOs seems to reduce the ankle joint role in propulsion as it impacts the ankle sagittal angles and moments.     

Fatigue matters: An intense 10 km run alters frontal and transverse plane joint kinematics in competitive and recreational adult runners

BackgroundFatigue is an essential component of distance running. Still, little is known about the effects of running induced fatigue on three-dimensional lower extremity joint movement, in particular in the frontal and transverse planes of motion.Research questionHow are non-sagittal plane lower extremity joint kinematics of runners altered during a 10 km treadmill run with near-maximum effort?MethodsIn a cross-sectional study design, we captured three-dimensional kinematics and kinetics at regular intervals throughout a 10 km treadmill run in 24 male participants (subdivided into a competitive and recreational runner group) at a speed corresponding to 105 % of their season-best time. We calculated average and peak joint angles at the hip, knee and ankle during the stance phase.ResultsWe observed peak deviations of 3.5°, 3° and 5° for the hip (more adduction), knee (more abduction) and ankle (more eversion) in the frontal plane when comparing the final (10 km) with the first (0 km) measurement. At the end of the run peak knee internal rotation angles increased significantly (up to 3° difference). Running with a more abducted knee joint and with a higher demand for hip abductor muscles in the unfatigued state was related to greater fatigue-induced changes of joint kinematics at the knee and hip.SignificanceThe fatigue related change of non-sagittal joint kinematics needs to be considered when addressing risk factors for running-related injuries, when designing shoe interventions as well as strengthening and gait retraining protocols for runners. We speculate that strengthening ankle invertors and hip abductors and monitoring the dynamic leg axis during running appear to be promising in preventing fatigue induced alterations of non-sagittal joint kinematics.     

Impact of subject-specific step width modification on the knee and hip adduction moments during gait

BackgroundPatients with hip osteoarthritis (OA) exhibit an increased step width (SW) during walking before and up to 2 years after total hip arthroplasty. Wider SW is associated with a reduction in the external knee adduction moment (KAM), but there is a lack of research regarding the effect of SW on the hip adduction moment (HAM).Research questionIs a wider SW an effective compensatory mechanism to reduce the hip joint loading? We hypothesized that (1) an increased SW reduces, (2) a decreased SW increases the KAM/HAM, and (3) secondary kinematic gait changes have an effect on the KAM/HAM.MethodsTwenty healthy individuals (24.0 ± 2.5 years of age) underwent instrumented gait analyses with 4 different subject-specific SW modifications (habitual, halved, double, and triple SW). The resulting external KAMs and HAMs were compared using statistical parametric mapping (SPM).ResultsPost hoc testing demonstrated significantly lower HAM for both the double (p < 0.001, 15–31 % and 61–98 % of the stance phase) and the triple SW (p < 0.001, 1–36 % and 58–98 %) compared to the habitual SW. The extent of the reduction at the first and second peak was comparable for HAM (15–25 % reduction) and less pronounced at the first peak of KAM (9–11 % reduction) compared to the second peak of KAM (19–28 % reduction). In contrast, halving the SW did not lead to a significant change in KAM or HAM compared to the habitual SW (p > 0.009).SignificanceAn increase in SW is an effective and simple gait mechanism to reduce the frontal plane knee and hip joint moments. However, hypothesis 2 could not be confirmed, as halving the SW did not cause a significant change in KAM or HAM. Given the results of the present study, gait retraining with regard to an increased SW may be an adequate, noninvasive option for the treatment of patients with hip OA.