scholarly journals Sagittal and Frontal Plane Knee Angular Jerk Effects During Prolonged Load Carriage

2020 ◽  
Author(s):  
Samantha M. Krammer
Keyword(s):  
Motion Capture ◽  
Repeated Measures ◽  
Injury Risk ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Musculoskeletal Injury ◽  
Load Carriage ◽  
Knee Motion ◽  
Effective Measure ◽  
Knee Jerk

Introduction: Musculoskeletal injuries are a costly military problem that routinely occur during training. Quantifying smoothness of knee motion, or angular knee jerk, may be an effective measure to monitor injury risk during training, but to date, the effects of body borne load and prolonged locomotion on angular knee jerk are unknown. Purpose: This study sought to quantify angular knee jerk for frontal and sagittal plane motion during prolonged load carriage. Methods: Eighteen participants had peak and cost of angular jerk for frontal and sagittal plane knee motion quantified while they walked (1.3 m/s) 60-minutes with three body borne loads (0, 15, and 30 kg). Statistical Analysis: Peak and cost of angular jerk for sagittal and frontal plane knee motion of stance phase (0 % - 100%) were derived from motion capture and IMU data and submitted to a repeated measures linear model to test the main effects and interaction of load (0, 15, and 30 kg) and time (0, 15, 30, 45, and 60 min.). Two one sided t-tests (TOSTs) were used to compare the motion capture- and IMU-derived measures of angular jerk for sagittal and frontal plane knee motion. Results: For the motion capture-derived jerk measures, body borne load increased peak and cost of angular jerk for sagittal (p < 0.001, p < 0.001) and frontal (p < 0.001, p < 0.001) plane knee motion, while time increased jerk cost (p = 0.001) of frontal plane knee motion. While the IMU-derived jerk measures exhibited similar increases in peak and cost of angular jerk for sagittal (p < 0.001, p < 0.001) and frontal (p = 0.027, p < 0.001) plane knee motion with addition of load, and in cost (p = 0.015) of angular jerk for frontal plane knee motion with time, they were not statistically equivalent to motion-capture derived measures (p > 0.05). Conclusion: Prolonged load carriage may lead to jerkier knee motion and increased knee musculoskeletal injury risk. Specifically, the jerkier knee motions exhibited with the addition of body borne load and longer walking time may increase the joint loading that leads to greater knee musculoskeletal injury risk.

Implications of Increased Lower Extremity Movement Variability on Fall Susceptibility at Increased Stride Lengths During Locomotion

2013 ◽  
Author(s):  
Andrew D. Nordin ◽  
Joshua P. Bailey ◽  
Janet S. Dufek
Keyword(s):  
Lower Extremity ◽  
Repeated Measures ◽  
Stride Length ◽  
Mixed Model ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Knee Joints ◽  
Lower Extremity Injury ◽  
Movement Variability ◽  
Heel Contact

The purpose of this examination was to explore the effects of stride length (SL) perturbations on walking gait, relative to preferred walking (PW) and running (PR), via lower extremity range of motion (ROM) variability. ROM variability at the hip, knee, and ankle joints, in the sagittal and frontal planes were used in evaluating motor control of gait, where increased gait variability has been previously implicated in fall susceptibly. Nine participants (5 male, 4 female; mean age 23.11±3.55 years, height 1.72±0.18m, mass 72.66±14.37kg) free from previous lower extremity injury were examined. Kinematic data were acquired using a 12-camera system (Vicon MX T40-S; 200Hz). Data filtering and interpolation included a low pass, 4th order, Butterworth filter (15Hz cutoff) and cubic spline. Five gait trials were completed for PW and PR, with subsequent SL manipulations computed as a percentage of leg length (LL). SL perturbations included 60%, 80%, 100%, 120%, and 140% of LL. Kinematic analysis involved one stride (two steps) during each gait trial, assessing ROM at the hip, knee, and ankle from heel contact to toe-off for each limb, in the sagittal and frontal planes. Variability was expressed using coefficient of variation (%). Comparisons were made using 3×7 (joint × stride condition) mixed model ANOVAs, with repeated measures on stride condition (α = 0.05), using SPSS 20.0. Differences in lower extremity ROM variability were detected among stride conditions in the frontal and sagittal planes (F[3.185,76.451] = 3.004, p = .033; F[4.595,110.279] = 2.834, p = .022, respectively). Greater ROM variability was observed at, and in excess of SLs of 100%LL relative to PW in the frontal plane (PW: 9.2±4.2%; 100%LL: 11.8±3.6%, p = .014; 120%LL: 13.5±5.8%, p = .046; 140%LL: 13.8±6.5%, p = .016), and between SLs of 80%LL and 120%LL in the sagittal plane (4.9±3.0%; 7.8±4.7%, p = .046, respectively). From this, PW appeared to occur within SLs of 60%LL to 80%LL, while SLs exceeding 100%LL resulted in increased lower extremity ROM variability. This may have consequences for fall susceptibility at increased stride lengths during walking. PR did not reveal significant variability differences (p>.05) compared to walking conditions in either the sagittal or frontal plane (7.5±5.0%; 12.8±7.7%, respectively), suggesting that running represents a separate, but stable gait pattern. In the sagittal plane, ROM variability was significantly lower at the hip (3.9±1.5%), relative to the ankle (8.4±1.6%, p<.001) and knee joints (7.4±2.6%, p = .001), suggesting that gait control may be more active at the ankle and knee joints. Future investigations should examine kinetic changes in gait when altering stride length.

scholarly journals Prolonged Load Carriage Impacts Magnitude and Velocity of Knee Adduction Biomechanics

2021 ◽  
Author(s):  
Gaervyn John Salverda
Keyword(s):  
Repeated Measures ◽  
Maximum Velocity ◽  
Frontal Plane ◽  
Load Carriage ◽  
Service Members ◽  
Occupational Activity ◽  
Knee Oa ◽  
Time To Peak ◽  
Projection Angle ◽  
Three Body

Introduction: Adopting knee adduction biomechanics during prolonged load carriage, a common military occupational activity, may increase service members knee osteoarthritis (OA) risk. Although service members reportedly increase knee adduction motions and moments during prolonged load carriage, it is unknown if either body borne load or walk duration increases velocity of knee adduction biomechanics, and subsequent knee OA risk. Varus thrust and alignment are also related to greater knee OA risk, yet it is unknown whether varus thrust and/or alignment are related to magnitude and velocity of knee adduction biomechanics during prolonged load carriage. Purpose: To determine whether body borne load and walk duration impacted magnitude and velocity of knee adduction biomechanics, or whether increases in knee adduction biomechanics are related to knee varus thrust or alignment. Methods: Seventeen participants (11 male/6 female, 23.2 ± 2.9 yrs, 1.8 ± .09 m, 71.0 ± 12.1 kg) had knee adduction biomechanics quantified while walking 1.3 m/s for 60 minutes with three body borne loads (0 kg, 15 kg, and 30 kg). Specifically, peak, average and maximum velocity, as well as time to peak, for knee adduction angle and moment, and varus thrust (first 16% of stance) were calculated at minutes 0, 30, and 60 of the load carriage task. Static knee alignment was calculated as the frontal plane knee projection angle. Statistical Analysis: Participants were defined as varus thrust (VT, n=8) or control (CON, n=9). Then, each knee adduction measurement was submitted to a repeated measures ANCOVA to test the main effect and interaction between body borne load (0 kg, 15 kg, and 30 kg), time (minutes 0, 30, and 60), and group (VT and CON), with static alignment considered a covariate. Results: A significant 3-way interaction for maximum varus thrust velocity (p=0.014), revealed the VT group exhibited greater maximum velocity at minutes 0 through 60 (p ≤ 0.038) with the 0 kg load, and minutes 0 and 60 (p ≤ 0.043) with the 15 kg load. Significant load by group interactions for magnitude (p=0.008) and average velocity (p=0.013) of varus thrust, and maximum KAA velocity (p=0.041) revealed VT participants exhibited larger and faster varus thrust and knee adduction angle than the CON group with the 0 kg and 15 kg loads (p < 0.050). Additionally, both magnitude and maximum velocity of KAM increased with the addition of load (p=0.009 and p=0.004), and walk duration increased magnitude of varus thrust (p=0.044). Static alignment was not a significant covariate for any knee adduction measure (p > 0.05). Conclusion: During prolonged load carriage participants adopted larger, faster knee adduction biomechanics, potentially increasing risk of knee OA. The VT group exhibited greater knee OA risk, and larger, faster knee adduction motions when walking with the lighter (0 kg and 15 kg) loads; while CON adopted increases in knee adduction biomechanics related to knee OA with the heavy (30 kg) load.

scholarly journals Lower Extremity Energy Absorption and Biomechanics During Landing, Part I: Sagittal-Plane Energy Absorption Analyses

2013 ◽  
Vol 48 (6) ◽  
pp. 748-756 ◽  
Author(s):  
Marc F. Norcross ◽  
Michael D. Lewek ◽  
Darin A. Padua ◽  
Sandra J. Shultz ◽  
Paul S. Weinhold ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Injury Risk ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Acl Injury ◽  
Knee Extension ◽  
Landing Biomechanics ◽  
Anterior Tibial ◽  
Acl Injury Risk ◽  
Risk Potential

Context: Eccentric muscle actions of the lower extremity absorb kinetic energy during landing. Greater total sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing has been associated with landing biomechanics considered high risk for anterior cruciate ligament (ACL) injury. We do not know whether groups with different INI EA magnitudes exhibit meaningful differences in ACL-related landing biomechanics and whether INI EA might be useful to identify ACL injury-risk potential. Objective: To compare biomechanical factors associated with noncontact ACL injury among sagittal-plane INI EA groups and to determine whether an association exists between sex and sagittal-plane INI EA group assignment to evaluate the face validity of using sagittal-plane INI EA to identify ACL injury risk. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: A total of 82 (41 men, 41 women; age = 21.0 ± 2.4 years, height = 1.74 ± 0.10 m, mass = 70.3 ± 16.1 kg) healthy, physically active individuals volunteered. Intervention(s): We assessed landing biomechanics using an electromagnetic motion-capture system and force plate during a double-legged jump-landing task. Main Outcome Measure(s): Total INI EA was used to group participants into high, moderate, and low tertiles. Sagittal- and frontal-plane knee kinematics; peak vertical and posterior ground reaction forces (GRFs); anterior tibial shear force; and internal hip extension, knee extension, and knee varus moments were identified and compared across groups using 1-way analyses of variance. We used a χ2 analysis to compare male and female representation in the high and low groups. Results: The high group exhibited greater knee-extension moment and posterior GRFs than both the moderate (P &lt; .05) and low (P &lt; .05) groups and greater anterior tibial shear force than the low group (P &lt; .05). No other group differences were noted. Women were not represented more than men in the high group (χ2 = 1.20, P = .27). Conclusions: Greater sagittal-plane INI EA likely indicates greater ACL loading, but it does not appear to influence frontal-plane biomechanics related to ACL injury. Women were not more likely than men to demonstrate greater INI EA, suggesting that quantification of sagittal-plane INI EA alone is not sufficient to infer ACL injury-risk potential.

scholarly journals Peak Lower Extremity Landing Kinematics in Dancers and Nondancers

2018 ◽  
Vol 53 (4) ◽  
pp. 379-385 ◽  
Author(s):  
Bethany L. Hansberger ◽  
Shellie Acocello ◽  
Lindsay V. Slater ◽  
Joseph M. Hart ◽  
Jatin P. Ambegaonkar
Keyword(s):  
Injury Risk ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Acl Injury ◽  
Group Activity ◽  
Dimensional System ◽  
Landing Biomechanics ◽  
Main Effects ◽  
Vertical Jumps ◽  
Jump Landings

Context:  Anterior cruciate ligament (ACL) injuries often occur during jump landings and can have detrimental short-term and long-term functional effects on quality of life. Despite frequently performing jump landings, dancers have lower incidence rates of ACL injury than other jump-landing athletes. Planned versus unplanned activities and footwear may explain differing ACL-injury rates among dancers and nondancers. Still, few researchers have compared landing biomechanics between dancers and nondancers. Objective:  To compare the landing biomechanics of dancers and nondancers during single-legged (SL) drop-vertical jumps. Design:  Cross-sectional study. Setting:  Laboratory. Patients or Other Participants:  A total of 39 healthy participants, 12 female dancers (age = 20.9 ± 1.8 years, height = 166.4 ± 6.7 cm, mass = 63.2 ± 16.4 kg), 14 female nondancers (age = 20.2 ± 0.9 years, height = 168.9 ± 5.0 cm, mass = 61.6 ± 7.7 kg), and 13 male nondancers (age = 22.2 ± 2.7 years, height = 180.6 ± 9.7 cm, mass = 80.8 ± 13.2 kg). Intervention(s):  Participants performed SL–drop-vertical jumps from a 30-cm–high box in a randomized order in 2 activity (planned, unplanned) and 2 footwear (shod, barefoot) conditions while a 3-dimensional system recorded landing biomechanics. Main Outcome Measure(s):  Overall peak sagittal-plane and frontal-plane ankle-, knee-, and hip-joint kinematics (joint angles) were compared across groups using separate multivariate analyses of variance followed by main-effects testing and pairwise-adjusted Bonferroni comparisons as appropriate (P &lt; .05). Results:  No 3-way interactions existed for sagittal-plane or frontal-plane ankle (Wilks λ = 0.85, P = .11 and Wilks λ = 0.96, P = .55, respectively), knee (Wilks λ = 1.00, P = .93 and Wilks λ = 0.94, P = .36, respectively), or hip (Wilks λ = 0.99, P = .88 and Wilks λ = 0.97, P = .62, respectively) kinematics. We observed no group × footwear interactions for sagittal-plane or frontal-plane ankle (Wilks λ = 0.94, P = .43 and Wilks λ = 0.96, P = .55, respectively), knee (Wilks λ = 0.97, P = .60 and Wilks λ = 0.97, P = .66, respectively), or hip (Wilks λ = 0.99, P = .91 and Wilks λ = 1.00, P = .93, respectively) kinematics, and no group × activity interactions were noted for ankle frontal-plane (Wilks λ = 0.92, P = .29) and sagittal- and frontal-plane knee (Wilks λ = 0.99, P = .81 and Wilks λ = 0.98, P = .77, respectively) and hip (Wilks λ = 0.88, P = .13 and Wilks λ = 0.85, P = .08, respectively) kinematics. A group × activity interaction (Wilks λ = 0.76, P = .02) was present for ankle sagittal-plane kinematics. Main-effects testing revealed different ankle frontal-plane angles across groups (F2,28 = 3.78, P = .04), with male nondancers having greater ankle inversion than female nondancers (P = .05). Conclusions:  Irrespective of activity type or footwear, female nondancers landed with similar hip and knee kinematics but greater peak ankle eversion and less peak ankle dorsiflexion (ie, positions associated with greater ACL injury risk). Ankle kinematics may differ between groups due to different landing strategies and training used by dancers. Dancers' training should be examined to determine if it results in a reduced occurrence of biomechanics related to ACL injury during SL landing.

scholarly journals Association Between Markerless Motion Capture Screenings and Musculoskeletal Injury Risk for Military Trainees: A Large Cohort and Reliability Study

2021 ◽  
Vol 9 (10) ◽  
pp. 232596712110416
Author(s):  
Ben R. Hando ◽  
W. Casan Scott ◽  
Jacob F. Bryant ◽  
Juste N. Tchandja ◽  
Ryan M. Scott ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Motion Capture ◽  
Injury Risk ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Musculoskeletal Injury ◽  
Retest Reliability ◽  
Intraclass Correlation Coefficients ◽  
Markerless Motion Capture ◽  
Test Retest Reliability

Background: Markerless motion capture (MMC) systems used to screen for musculoskeletal injury (MSKI) risk have become popular in military and collegiate athletic settings. However, little is known regarding the test-retest reliability or, more importantly, the ability of these systems to accurately identify individuals at risk for MSKI. Purpose: To determine the association between scores from a proprietary MMC movement screen test and the likelihood of suffering a subsequent MSKI and establish the test-retest reliability of the MMC system used. Study Design: Cohort study; Level of evidence, 3. Methods: Trainees for the Air Force Special Warfare program underwent MMC screenings immediately before entering the 8-week training course. MSKI data were extracted from a database for the surveillance period for each trainee. Logistic regression analyses were performed to identify associations between baseline MMC scores and the likelihood of suffering any MSKI or, specifically, a lower extremity MSKI. The test-retest portion of the study collected MMC scores from 10 separate participants performing 4 trials of the standard test procedures. Reliability was assessed using intraclass correlation coefficients by a single rater. Results: Overall, 1570 trainees, of whom 800 (51%) suffered an MSKI, were included in the analysis. MMC scores poorly predicted the likelihood of any or a lower extremity MSKI (odds ratio, 1.01-1.02). Further, receiver operating characteristic curve analyses demonstrated poor sensitivity and specificity for prediction of MSKI with MMC scores (area under the curve = 0.53). Finally, intraclass correlation coefficients from the test-retest analysis of MMC scores ranged from 0.157 to 0.602. Conclusion: This MMC system displayed poor to moderate test-retest reliability and did not demonstrate the ability to discriminate between individuals who were and were not likely to suffer an MSKI.

Pelvifemoral Kinematics while Ascending Single Steps of Different Heights

2010 ◽  
Vol 26 (3) ◽  
pp. 290-294 ◽  
Author(s):  
Richard W. Bohannon ◽  
Jason Smutnick
Keyword(s):  
Motion Capture ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Step Height ◽  
Motion Capture System ◽  
Pelvic Rotation ◽  
Hip Flexion

Motion of the femur and pelvis during hip flexion has been examined previously, but principally in the sagittal plane and during nonfunctional activities. In this study we examined femoral elevation in the sagittal plane and pelvic rotation in the sagittal and frontal planes while subjects flexed their hips to ascend single steps. Fourteen subjects ascended single steps of 4 different heights leading with each lower limb. Motion of the lead femur and pelvis during the flexion phase of step ascent was tracked using an infrared motion capture system. Depending on step height and lead limb, step ascent involved elevation of the femur (mean 47.2° to 89.6°) and rotation of the pelvis in both the sagittal plane (tilting: mean 2.6° to 9.7°) and frontal plane (listing: mean 4.2° to 11.9°). Along with maximum femoral elevation, maximum pelvic rotation increased significantly (p< .001) with step height. Femoral elevation and pelvic rotation during the flexion phase of step ascent were synergistic (r= .852–.999). Practitioners should consider pelvic rotation in addition to femoral motion when observing individuals’ ascent of steps.

scholarly journals Validation of a Commercially Available Markerless Motion-Capture System for Trunk and Lower Extremity Kinematics During a Jump-Landing Assessment

2021 ◽  
Vol 56 (2) ◽  
pp. 177-190
Author(s):  
Timothy C. Mauntel ◽  
Kenneth L. Cameron ◽  
Brian Pietrosimone ◽  
Stephen W. Marshall ◽  
Anthony C. Hackney ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Motion Capture ◽  
Joint Angle ◽  
Sagittal Plane ◽  
Frontal Plane ◽  
Lower Extremity Injury ◽  
Joint Angles ◽  
Jump Landing ◽  
Markerless Motion Capture ◽  
Motion Capture Systems

Context Field-based, portable motion-capture systems can be used to help identify individuals at greater risk of lower extremity injury. Microsoft Kinect-based markerless motion-capture systems meet these requirements; however, until recently, these systems were generally not automated, required substantial data postprocessing, and were not commercially available. Objective To validate the kinematic measures of a commercially available markerless motion-capture system. Design Descriptive laboratory study. Setting Laboratory. Patients or Other Participants A total of 20 healthy, physically active university students (10 males, 10 females; age = 20.50 ± 2.78 years, height = 170.36 ± 9.82 cm, mass = 68.38 ± 10.07 kg, body mass index = 23.50 ± 2.40 kg/m2). Intervention(s) Participants completed 5 jump-landing trials. Kinematic data were simultaneously recorded using Kinect-based markerless and stereophotogrammetric motion-capture systems. Main Outcome Measure(s) Sagittal- and frontal-plane trunk, hip-joint, and knee-joint angles were identified at initial ground contact of the jump landing (IC), for the maximum joint angle during the landing phase of the initial landing (MAX), and for the joint-angle displacement from IC to MAX (DSP). Outliers were removed, and data were averaged across trials. We used intraclass correlation coefficients (ICCs [2,1]) to assess intersystem reliability and the paired-samples t test to examine mean differences (α ≤ .05). Results Agreement existed between the systems (ICC range = −1.52 to 0.96; ICC average = 0.58), with 75.00% (n = 24/32) of the measures being validated (P ≤ .05). Agreement was better for sagittal- (ICC average = 0.84) than frontal- (ICC average = 0.35) plane measures. Agreement was best for MAX (ICC average = 0.77) compared with IC (ICC average = 0.56) and DSP (ICC average = 0.41) measures. Pairwise comparisons identified differences for 18.75% (6/32) of the measures. Fewer differences were observed for sagittal- (0.00%; 0/15) than for frontal- (35.29%; 6/17) plane measures. Between-systems differences were equivalent for MAX (18.18%; 2/11), DSP (18.18%; 2/11), and IC (20.00%; 2/10) measures. The markerless system underestimated sagittal-plane measures (86.67%; 13/15) and overestimated frontal-plane measures (76.47%; 13/17). No trends were observed for overestimating or underestimating IC, MAX, or DSP measures. Conclusions Moderate agreement existed between markerless and stereophotogrammetric motion-capture systems. Better agreement existed for larger (eg, sagittal-plane, MAX) than for smaller (eg, frontal-plane, IC) joint angles. The DSP angles had the worst agreement. Markerless motion-capture systems may help clinicians identify individuals at greater risk of lower extremity injury.

scholarly journals Agreement between Inertia and Optical Based Motion Capture during the VU-Return-to-Play- Field-Test

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 831
Author(s):  
Chris Richter ◽  
Katherine A. J. Daniels ◽  
Enda King ◽  
Andrew Franklyn-Miller
Keyword(s):  
Motion Capture ◽  
Field Test ◽  
Sagittal Plane ◽  
Inertial Sensor ◽  
Frontal Plane ◽  
Return To Play ◽  
Motion Capture System ◽  
Ankle Kinematics ◽  
Accuracy And Precision ◽  
Hip Flexion

The validity of an inertial sensor-based motion capture system (IMC) has not been examined within the demands of a sports-specific field movement test. This study examined the validity of an IMC during a field test (VU®) by comparing it to an optical marker-based motion capture system (MMC). Expected accuracy and precision benchmarks were computed by comparing the outcomes of a linear and functional joint fitting model within the MMC. The kinematics from the IMC in sagittal plane demonstrated correlations (r2) between 0.76 and 0.98 with root mean square differences (RMSD) < 5°, only the knee bias was within the benchmark. In the frontal plane, r2 ranged between 0.13 and 0.80 with RMSD < 10°, while the knee and hip bias was within the benchmark. For the transversal plane, r2 ranged 0.11 to 0.93 with RMSD < 7°, while the ankle, knee and hip bias remained within the benchmark. The findings indicate that ankle kinematics are not interchangeable with MMC, that hip flexion and pelvis tilt higher in IMC than MMC, while other measures are comparable to MMC. Higher pelvis tilt/hip flexion in the IMC can be explained by a one sensor tilt estimation, while ankle kinematics demonstrated a considerable level of disagreement, which is likely due to four reasons: A one sensor estimation, sensor/marker attachment, movement artefacts of shoe sole and the ankle model used.

Effect of Rear-Foot Orthotics on Postural Control in Healthy Subjects

2001 ◽  
Vol 10 (1) ◽  
pp. 36-47 ◽  
Author(s):  
Jay Hertel ◽  
Craig R. Denegar ◽  
W.E. Buckley ◽  
Neil A. Sharkey ◽  
Wayne L. Stokes
Keyword(s):  
Young Adults ◽  
Postural Control ◽  
Repeated Measures ◽  
Healthy Subjects ◽  
Sagittal Plane ◽  
Center Of Pressure ◽  
Frontal Plane ◽  
Type Design ◽  
Single Leg Stance ◽  
Healthy Participants

Objective:To identify changes in sagittal- and frontal-plane center of pressure (COP) excursion length and velocity during single-leg stance under 6 orthotic conditions.Design:1 × 6 repeated-measures.Setting:University biomechanics laboratory.Participants:Fifteen healthy young adults without excessive forefoot, arch, or rear-foot malalignments.Measurements:Selected variables of COP length and velocity were calculated in both the frontal and sagittal planes during three 5-second trials of quiet unilateral stance.Methods:Postural control was assessed under 6 conditions: shoe only and 5 orthotics.Results:The medially posted orthotic caused the least frontal COP length and velocity, and the Cramer Sprained Ankle Orthotic® caused the greatest frontal-plane sway. No significant differences were found between the different orthotic conditions in sagittal-plane measures.Conclusions:Differently posted rear-foot orthotics had various effects on frontal-plane postural control in healthy participants. Further research is needed on pathological populations.

Sign in / Sign up

Export Citation Format

Share Document