Effects of two different knee tape procedures on lower‐limb kinematics and kinetics in recreational runners

The purpose of this study was to compare the effects of Mulligan's tape (MT) and kinesio tape (KT) with no tape (NT) on hip and knee kinematics and kinetics during running. Twenty‐nine female recreational runners performed a series of ‘run‐throughs’ along a 10‐m runway under the three taping conditions. Two force plates and a 14‐camera Vicon motion analysis system (Oxford Metrics, Inc., Oxford, UK) captured kinematic and kinetic data for each dependent variable from ground contact to toe off. Comparisons of each dependent variable under three taping conditions were assessed through Statistical Package for the Social Sciences (SPSS; SPSS, Inc., Chicago, Illinois, USA; P‐value < 0.01) using repeated measure analyses of variance. For each dependent variable with a P‐value < 0.01, repeated measures with pairwise comparisons and Bonferroni adjustment were conducted to compare the three taping conditions. MT induced a significant reduction in anterior and posterior hip forces, knee flexion angular velocity, knee extensor moments, and hip flexion and extension moments compared with NT and KT (P = 0.001). There was no difference in hip or knee, kinematics or kinetics, between KT and NT (P = 1.000). MT appears to influence hip and knee biomechanics during running in an asymptomatic sample, whereas KT appeared to be biomechanically not different from NT.     

A comparison of the kinematics and kinetics of barefoot and shod running in children with cerebral palsy

BackgroundThe biomechanics of barefoot and shod running are different for typically developing children but unknown for children with cerebral palsy (CP). Such differences may have implications for injury and performance.AimsThe primary aims of this study were to compare the lower limb biomechanics of barefoot and shod running in children with CP, and to determine whether any differences were the same in GMFCS levels I and II.MethodsThis cross-sectional study examined 38 children with CP (n = 24 (GMFCS) level I; n = 14 GMFCS II), running overground at 3 speeds (jog, run, sprint) in barefoot and shod conditions. Marker trajectories and force plate data were recorded, and lower limb kinematics, kinetics and spatiotemporal variables were derived. Differences between barefoot and shod running were analysed using linear mixed models.ResultsFor both GMFCS levels, barefoot running resulted in higher loading rates, but smaller impact peaks at all speeds. Barefoot running was associated with greater hip and knee power; less ankle dorsiflexion and hip flexion at initial contact, and less ankle and knee range of motion during stance, compared to shod running, at all speeds. Barefoot stride length was shortened, and cadence increased compared to shod during jogging and running but not sprinting. For GMFCS level I only, barefoot running involved a higher incidence of forefoot strike, greater ankle power generation and less hip range of motion during stance.SignificanceRunning barefoot may facilitate running performance by increasing power generation at the ankle in children with CP, GMFCS level I. Higher barefoot loading rates may have implications for performance and injury.     

Effect of Mulligan's and Kinesio knee taping on adolescent ballet dancers knee and hip biomechanics during landing

Taping is often used to manage the high rate of knee injuries in ballet dancers; however, little is known about the effect of taping on lower‐limb biomechanics during ballet landings in the turnout position. This study investigated the effects of Kinesiotape (KT), Mulligan's tape (MT) and no tape (NT) on knee and hip kinetics during landing in three turnout positions. The effect of taping on the esthetic execution of ballet jumps was also assessed. Eighteen pain‐free 12–15‐year‐old female ballet dancers performed ballet jumps in three turnout positions, under the three knee taping conditions. A Vicon Motion Analysis system (Vicon Oxford, Oxford, UK) and Advanced Mechanical Technology, Inc. (Watertown, Massa chusetts, USA) force plate collected lower‐limb mechanics. The results demonstrated that MT significantly reduced peak posterior knee shear forces (P = 0.025) and peak posterior (P = 0.005), medial (P = 0.022) and lateral (P = 0.014) hip shear forces compared with NT when landing in first position. KT had no effect on knee or hip forces. No significant differences existed between taping conditions in all landing positions for the esthetic measures. MT was able to reduce knee and the hip forces without affecting the esthetic performance of ballet jumps, which may have implications for preventing and managing knee injuries in ballet dancers.     

Isokinetic knee function in healthy subjects with and without Kinesio taping

ObjectiveThis study examined the difference in the isokinetic knee performance in healthy subjects with and without the Kinesio tape application onto the skin surface overlying the vastus medialis.DesignA cross-sectional experimental study.SettingClinical setting.Participants30 healthy participants.Main outcome measuresMaximal concentric knee extension and flexion at three angular velocities (60, 120 and 180°/s) were measured with an isokinetic dynamometer. Normalized peak torque, normalized total work done and time to peak torque of knee extension and flexion were compared by repeated measures ANOVA.ResultsThere was no significant main effect in ANOVA in normalized peak torque and normalized total work done between taping conditions and angular velocities. Conversely, participants demonstrated significant shorter time to peak extension torque with the tape condition (p = 0.03). Pair-wise comparisons indicated that such time reduction (36–101 ms) occurred at all three angular velocities (p < 0.01).ConclusionThis investigation demonstrated the application of Kinesio tape did not alter the muscle peak torque generation and total work done but shortened the time to generate peak torque. This finding may contribute to the rationale in injury prevention and rehabilitation in athletes with Kinesio taping.     

Comparison of instantaneous knee kinematics during walking and running

BackgroundAccurate measurements of in-vivo knee joint kinematics are essential to elucidate healthy knee motion and the changes that accompany injury and repair. Although numerous experimental measurements have been reported, the accurate non-invasive analysis of in-vivo knee kinematics remains a challenge in biomechanics.Research questionThe study objective was to investigate in-vivo knee kinematics before, at, and after contact during walking and running using a combined high-speed dual fluoroscopic imaging system (DFIS) and magnetic resonance (MR) imaging technique.MethodsThree-dimensional (3D) knee models of ten participants were created using MR images. Knee kinematics during walking and running were determined using high-speed DFIS. The 3D knee models were then related to fluoroscopic images to obtain in-vivo six-degrees-of-freedom knee kinematics.ResultsBefore contact knee flexion, external femoral rotation, and proximal-distal distance were 11.9°, 3.4°, and 1.0 mm greater during running compared to walking, respectively. Similar differences were observed at initial contact (9.9°, 7.9°, and 0.9 mm, respectively) and after contact (6.4°, 2.2°, and 0.8 mm, respectively). Posterior femoral translation at initial contact was also increased during running compared to walking.SignificanceThis study demonstrated accurate instantaneous in-vivo knee kinematic characteristics that may further the understanding of the intrinsic biomechanics of the knee during gait.     

The effect of fatigue on running mechanics in older and younger runners

BackgroundThe presence of fatigue has been shown to modify running biomechanics. Throughout a run individuals become more fatigued, and the effectiveness of the musculoskeletal protective mechanism can diminish. Older adults are at an elevated risk for sustaining an overuse running related injury. This can be partially explained by changes in the musculoskeletal system and load attenuation.Research questionThe purpose was to compare post-fatigue running mechanics between older and younger runners.MethodsThirty runners (15 young, 15 older) between the ages of 18–65 participated in this study. All participants ran at least 15 miles/week. Running kinematics were captured using a 10-camera motion capture system while participants ran over a 10-m runway with force platforms collecting kinetic data under two conditions: C1: rested state at a controlled pace of 3.5 m/s ( ± 5%); C2: post-exertional protocol where pace was not controlled, rather it was monitored based on heartrate and RPE representative of somewhat-hard to hard intensity exercise. Prior to C2, participants underwent an exertional protocol that consisted of a maximal exercise test to induce fatigue and a required cool-down. A 2 (state of fatigue) x 2 (age) MANOVA was run to test for the effects of fatigue and age and their interactions. Results: No state of fatigue x age interaction was observed. A main effect of age for peak knee extension moment (Y > O; p = 0.01), maximum knee power (Y > O; p = 0.04), maximum hip power (O >Y; p = 0.04), and peak vertical ground reaction force (Y > O; p = 0.007). Regardless of age, participants exhibited decreased knee ROM (p = 0.007) and greater hip extension moment (p < 0.001) in C2 compared to C1.ConclusionWhile different in knee and hip mechanics overall, the subtle differences observed demonstrate that older runners exhibit comparable gait adaptions post-fatigue to younger volume-matched runners.     

Effects of Kinesio tape on supporting medial foot arch in runners with functional flatfoot: a preliminary study

ABSTRACT

This study aimed to evaluate the anti-pronation effects of Kinesio tape on flexible flatfoot during running. Nine volunteers participated in a crossover trail of two conditions: with Kinesio tape (KT) or without taping (NT). The running consisted of 9 stages of different inclines on a treadmill over 28 minutes. Navicular drop distance (NDD) was measured before and after the running. Electromyography, the relative plantar pressure, Rating of Perceived Exertion and Visual Analogue Scale were recorded at each stage. After the application of Kinesio tapes over the tibialis posterior and transverse arch, the NDD reduced significantly and the relative posterior pressure reduced during stage 8. Without taping, the NDD decreased slightly after exercise. Comparing between conditions, the tibialis anterior were more activated with Kinesio tape in stages 4 and 5. During the latter half of the running, the medial gastrocnemius and peroneus longus reduced their activity in the KT and NT conditions respectively. In conclusion, the Kinesio tapes intended to facilitate the tibialis posterior and reinforce the transverse arch can reduce NDD in individuals with flexible flatfoot immediately after application, and increase muscle activity of their tibialis anterior during the first 15 minutes of the running.     

Biomechanics of running with rocker shoes

Objectives

Load reduction is an important consideration in conservative management of tendon overuse injuries such as Achilles tendinopathy. Previous research has shown that the use of rocker shoes can reduce the positive ankle power and plantar flexion moment which might help in unloading the Achilles tendon. Despite this promising implication of rocker shoes, the effects on hip and knee biomechanics remain unclear. Moreover, the effect of wearing rocker shoes on different running strike types is unexplored. The aim of this study was to investigate biomechanics of the ankle, knee and hip joints and the role of strike type on these outcomes.

Kinematic adaptation and changes in gait classification in running compared to walking in children with unilateral spastic cerebral palsy

BackgroundClassification of sagittal gait patterns in unilateral spastic cerebral palsy (CP) provides direct implication for treatment. Five types are described: type 0 has minor gait deviation; type 1 has inadequate ankle dorsiflexion in swing; type 2 has inadequate ankle dorsiflexion throughout the gait cycle; types 3 and 4 have abnormal function of the knee and hip joint respectively. During gait analysis of children with unilateral spastic CP we observed frequently that a knee flexion deficit disappeared during running. That may have an impact on classification and treatment.Research questionDoes the classification type change while running and how do patients’ kinematics adapt to running?Methods64 children with unilateral spastic CP were classified using instrumented gait analysis for walking and running. The deviation of four parameters from typically developing children (TD) were used to distinguish between types: peak ankle dorsiflexion in swing for type 1, peak ankle dorsiflexion in stance for type 2, knee range of motion for type 3, and hip range of motion for type 4. A three-factor ANOVA for factors group (CP/TD), locomotion (walk/run) and limb side (in-/uninvolved) was conducted.ResultsThe number of patients with type 1, 3 and 4 decreased considerably from walking to running, whereas, the number of type 0 and 2 patients increased. The ANOVA showed that three of four parameters of patients’ pathologic limb adapt similarly to TD to running, except for the ankle dorsiflexion in stance.SignificanceRunning shows that there is a natural way to resolve abnormalities. Therefore, recommended treatments of hip and knee joint abnormalities based on the walking classification can be questioned and additional running analysis may be important for surgical decision making.     

The between-day repeatability,standard error of measurement and minimal detectable change for discrete kinematic parameters during treadmill running

BackgroundKinematic parameters of the trunk, pelvis and lower limbs are frequently associated with both running injuries and performance, and the target of clinical interventions. Currently there is limited evidence reporting the between-day repeatability of discrete kinematic parameters of the trunk, pelvis and lower limbs during treadmill running.Research questionWhat is the between-day repeatability, standard error of measurement and minimal detectable change of discrete kinematic parameters of the trunk, pelvis and lower limbs during treadmill running?Methods16 healthy participants attended two kinematic data collection sessions two weeks apart. Three-dimensional kinematic data were collected while participants ran on a motorised treadmill at 3.2 m/s. The interclass correlation coefficient, standard error of measurement and minimal detectable change were calculated for discrete kinematic parameters at initial contact, toe off, peak angles and joint excursions during the stance phase of running.ResultsGood to excellent repeatability with low standard error of measurement and minimal detectable change values were observed for sagittal and frontal plane kinematics at initial contact (Range: ICC, 0.829−0.941; SEM, 0.6°- 2.6°; MDC, 1.5°- 7.2) and peak angles during stance (Range: ICC, 0.799 – 0.946; SEM, 0.6°- 2.6°; MDC, 1.7°- 7.1°). Peak transverse plane kinematics of the hip (ICC, 0.783; SEM, 3.2°; MDC, 8.7°) and knee (ICC, 0.739; SEM, 3°; MDC, 8.4°) demonstrated moderate between-day repeatability with large SEM and MDC values. Kinematics at toe off demonstrated the lowest ICC values and largest measurement errors of all parameters (Range: ICC, 0.109 – 0.900; SEM, 0.8°- 5.7°; MDC, 2.5°- 15.7°).SignificanceThis is the first study detailing the measurement error and minimal detectable change for discrete kinematic parameters of the trunk and pelvis during treadmill running. The reported values may provide a useful reference point for future studies investigating between-day differences in running kinematics.     

Biomechanical alterations in individuals with Achilles tendinopathy during running and hopping: A systematic review with meta-analysis

IntroductionBiomechanical alterations during running and hopping in people with Achilles tendinopathy (AT) may provide treatment and prevention targets. This review identifies and synthesises research evaluating biomechanical alterations among people with AT during running, jumping and hopping.MethodMEDLINE, EMBASE, CiNAHL and SPORTDiscus were searched in July 2018 for case control, cross-sectional and prospective studies investigating kinematics, kinetics, plantar pressures and neuromuscular activity in AT participants during running or hopping. Study quality was assessed with a modified version of the Downs and Black quality checklist, and evidence grading applied.Results16 studies reported 249 outcomes, of which 17% differed between groups. Reduced peroneus longus (standardized mean difference [95%CI]; −0.53 [−0.98, −0.09]) and medial gastrocnemius (−0.60 [−1.05, −0.15]) amplitude in AT runners versus control was found (limited evidence). Increased hip adduction impulse 1.62 [0.69, 2.54], hip peak external rotation moment (1.55 [0.63, 2.46] and hip external rotation impulse (1.45 [0.55, 2.35]) was found in AT runners versus control (limited evidence). Reduced anterior (−0.94 [−1.64, −0.24] and greater lateral (−0.92 [−1.61, −0.22]) displacement of plantar pressure preceded AT in runners (limited evidence). Delayed onsets of gluteus medius (1.95 [1.07, 2.83] and gluteus maximus (1.26 [0.48, 2.05] and shorter duration of gluteus maximus activation (−1.41 [−2.22, −0.61] was found during shod running in the AT group versus control (limited evidence). Earlier offset time of gluteus maximus (−1.03 [−1.79, −0.27] and shorter duration of activation of gluteus medius (−0.18 [−0.24, −0.12] during running in AT runners versus control was found (limited evidence). Reduced leg stiffness was found in the affected side during submaximal hopping (−0.39 [−0.79, −0.00]) (limited evidence).ConclusionThis review identified potential biomechanical treatment targets in people with AT. The efficacy of treatments targeting these biomechanics should be assessed.Systematic review registryPROSPERO registration number: CRD42016048636.     

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.     

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.     

Mechanical effects of medial and lateral wedged orthoses during running

ObjectiveThe aim of the current investigation was to examine the effects of orthoses with 5° medial and lateral wedges on knee joint kinetics during the stance phase of running.DesignRepeated measures.SettingLaboratory.ParticipantsTwelve recreational runners.Outcome measurementsTwelve male participants ran over a force platform at 4.0 m/s in three different conditions (medial orthotic, lateral orthotic and no-orthotic). Lower limb kinematics were collected using an 8-camera motion capture system allowing knee kinetics to be quantified using a musculoskeletal modelling approach. Differences in knee joint kinetics between orthotic conditions were examined using one-way repeated measures ANOVA.ResultsThe results showed that peak patellofemoral force was significantly increased in the medial (31.81 N/kg) and lateral (31.29 N/kg) wedged orthoses, in comparison to the no-orthotic (29.61 N/kg) condition. In addition, the peak knee adduction moment was significantly increased in the medial (1.10 Nm/kg) orthoses, in comparison to the lateral (0.87 Nm/kg) condition.ConclusionsThe results from this study indicate that lateral orthoses may be effective in attenuating runners risk from medial tibiofemoral compartment OA, but that wedged orthoses may enhance their risk from patellofemoral pain.     

Analysis of the use of insoles in the dynamic stability of the lower limbs in recreational runners: An exploratory study.

BackgroundThe use of insoles, which is increasingly widespread, can promote changes in biomechanics during running.Research questionCan the use of insoles with various patterns of infracapital support influence factors related to the dynamic stability of the lower limbs during running on a treadmill in recreational runners?MethodsThis is controlled single-blind repeated measures. Static baropodometric data were collected, as well as kinematic data for the lower limbs and electromyographic data for the gluteus maximus and gluteus medius muscles, for twelve recreational runners on a treadmill using four models of insoles (neutral and with forefoot elements - infracapital bar).ResultsNeutral insoles were able to reduce laterolateral displacement, increase the displacement of the mass to the posterior, and increase the lateral rotation of the left knee and medial rotation of the right hip. Insoles with a 2 mm total infracapital bar were able to move the mass to the posterior, increase laterolateral displacement and activate the gluteus medius. Insoles with a 2 mm medial infracapital bar were able to increase the displacement of the mass to the posterior, increase the adduction of left hip and the medial rotation of right hip, and activate the gluteus medius. Insoles with a 4 mm medial infracapital element were able to move the body mass to the posterior and to the left, increase laterolateral displacement, increase the adduction of left hip, the medial rotation of right hip and the abduction of right knee.SignificanceThe insoles evaluated in the present study were able to modify biomechanical variables of recreational runners related to dynamic stability during running on a treadmill and static baropodometric variables.     

Prospective running assessments among division I cross-country athletes

ObjectivesTo prospectively monitor biomechanics, session-rating of perceived exertion (sRPE), and wellness in a cohort of collegiate Division-1 cross-country athletes over the course of a single competitive season.DesignProspective cohort study.MethodsHealthy Division-1 cross-country athletes (9 males, 13 females) were prospectively followed over a single competitive cross-country season. Wearable sensors were used to collect biomechanics twice per week, along with surveys to assess sRPE and wellness. Mixed model linear regressions were used to assess the relationship among biomechanical measures to sRPE, and to wellness z-scores.ResultsStride length, contact time, impact g, pace, weekly mileage, and running a meet in the day prior to the recorded run explained 25.4% of the variance in sRPE scores across the season (R² = 0.254, p < 0.001). Contact time and braking g helped explain 3.7% of the variance in wellness (R² = 0.037, F = 5.70, p = 0.01).ConclusionsThere were several identified associations between gait biomechanics and sRPE, yet minimal associations with wellness measures. These findings suggest there are movement adaptations associated with perceived running intensity, however biomechanical measures alone do not lend additional insight into wellness measures.     

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.     

Does increased midsole bending stiffness of sport shoes redistribute lower limb joint work during running?

ObjectivesTo investigate if lower limb joint work is redistributed when running in a shoe with increased midsole bending stiffness compared to a control shoe.DesignWithin-subject with two conditions: (1) commercially available running shoe and (2) the same shoe with carbon fibre inserts to increase midsole bending stiffness.MethodsThirteen male, recreational runners ran on an instrumented treadmill at 3.5 m/s in each of the two shoe conditions while motion capture and force platform data were collected. Positive and negative metatarsophalangeal (MTP), ankle, knee, and hip joint work were calculated and statistically compared between conditions.ResultsRunning in the stiff condition (with carbon fibre inserts) resulted in significantly more positive work and less negative work at the MTP joint, and less positive work at the knee joint.ConclusionsIncreased midsole bending stiffness resulted in a redistribution of positive lower limb joint work from the knee to the MTP joint. A larger MTP joint plantarflexor moment due to increased vGRF at the instant of peak positive power and an earlier onset of MTP joint plantarflexion velocity were identified as the reasons for lower limb joint work redistribution.     

Verification of validity of gait analysis systems during treadmill walking and running using human pose tracking algorithm

BackgroundThe human tracking algorithm called OpenPose can detect joint points and measure segment and joint angles. However, the validity of gait analysis using OpenPose has not been examined yet.Research questionWhat is the validity of OpenPose-based gait analysis?MethodsTwenty-four healthy young people participated in this study. The participants were assessed during walking and running. Pelvic segment angles, and hip, knee, and ankle joint angles during treadmill walking and running were measured using VICON. Simultaneously, images were captured using digital cameras from the right and back sides. After processing with OpenPose, the corresponding angles were measured from the estimated joint points. To validate these estimations, linear regression analysis was performed, and intraclass correlation coefficients [ICCs (2, 1)] between the data obtained by OpenPose and VICON were calculated. Furthermore, the agreement between the data obtained by OpenPose and VICON was assessed by Bland–Altman analysis.ResultsFor most ranges of motion (ROM) in the sagittal plane, the hip, knee, and ankle joints had large coefficients of determination, without proportional biases. For most peak angles in the sagittal plane, the knee and ankle joints had large coefficients of determination without proportional biases, although the hip joint had nonsignificant coefficients of determination and proportional biases. In particular, for the hip flexion-extension ROM and peak knee flexion angle during running and the knee ROM during slow walking, the ICCs showed good to excellent agreement. However, for the parameters of the pelvis and hip joint in the frontal plane, there were nonsignificant coefficients of determination and poor ICCs with fixed and proportional biases.SignificanceThe lower limb ROM in the sagittal plane during gait can be measured by the OpenPose-based motion analysis system. The markerless systems have the advantage of being more economical and convenient than conventional methods.     

The effects & mechanisms of increasing running step rate: A feasibility study in a mixed-sex group of runners with patellofemoral pain

ObjectivesTo explore feasibility of recruitment and retention of runners with patellofemoral pain (PFP), before delivering a step rate intervention.DesignFeasibility study.SettingHuman performance laboratory.ParticipantsA mixed-sex sample of runners with PFP (n = 11).Main outcome measuresAverage/worst pain and the Kujala Scale were recorded pre/post intervention, alongside lower limb kinematics and surface electromyography (sEMG), sampled during a 3 KM treadmill run.ResultsRecruitment and retention of a mixed-sex cohort was successful, losing one participant to public healthcare and with kinematic and sEMG data lost from single participants only. Clinically meaningful reductions in average (MD = 2.1, d = 1.7) and worst pain (MD = 3.9, d = 2.0) were observed. Reductions in both peak knee flexion (MD = 3.7°, d = 0.78) and peak hip internal rotation (MD = 5.1°, d = 0.96) were observed, which may provide some mechanistic explanation for the identified effects. An increase in both mean amplitude (d = 0.53) and integral (d = 0.58) were observed for the Vastus Medialis Obliqus (VMO) muscle only, of questionable clinical relevance.ConclusionsRecruitment and retention of a mixed sex PFP cohort to a step rate intervention involving detailed biomechanical measures is feasible. There are indications of both likely efficacy and associated mechanisms. Future studies comparing the efficacy of different running retraining approaches are warranted.