scholarly journals Validation of a Novel Device for the Knee Monitoring of Orthopaedic Patients

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5193 ◽  
Author(s):  
Mahmut Enes Kayaalp ◽  
Alison N. Agres ◽  
Jan Reichmann ◽  
Maxim Bashkuev ◽  
Georg N. Duda ◽  
...  
Keyword(s):  
Motion Capture ◽  
Stance Phase ◽  
Swing Phase ◽  
Flexion Angle ◽  
Sensor System ◽  
Measurement Unit ◽  
Data Set ◽  
Orthopaedic Patients ◽  
Peak Knee ◽  
Good For

Fast-track surgery is becoming increasingly popular, whereas the monitoring of postoperative rehabilitation remains a matter of considerable debate. The aim of this study was to validate a newly developed wearable system intended to monitor knee function and mobility. A sensor system with a nine-degree-of-freedom (DOF) inertial measurement unit (IMU) was developed. Thirteen healthy volunteers performed five 10-meter walking trials with simultaneous sensor and motion capture data collection. The obtained kinematic waveforms were analysed using root mean square error (RMSE) and correlation coefficient (CC) calculations. The Bland–Altman method was used for the agreement of discrete parameters consisting of peak knee angles between systems. To test the reliability, 10 other subjects with sensors walked a track of 10 metres on two consecutive days. The Pearson CC was excellent for the walking data set between both systems (r = 0.96) and very good (r = 0.95) within the sensor system. The RMSE during walking was 5.17° between systems and 6.82° within sensor measurements. No significant differences were detected between the mean values observed, except for the extension angle during the stance phase (E1). Similar results were obtained for the repeatability test. Intra-class correlation coefficients (ICCs) between systems were excellent for the flexion angle during the swing phase (F1); good for the flexion angle during the stance phase (F2) and the re-extension angle, which was calculated by subtracting the extension angle at swing phase (E2) from F2; and moderate for the extension angle during the stance phase (E1), E2 and the range of motion (ROM). ICCs within the sensor measurements were good for the ROM, F2 and re-extension, and moderate for F1, E1 and E2. The study shows that the novel sensor system can record sagittal knee kinematics during walking in healthy subjects comparable to those of a motion capture system.

scholarly journals Validity Evaluation of an Inertial Measurement Unit (IMU) in Gait Analysis Using Statistical Parametric Mapping (SPM)

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3667
Author(s):  
Sangheon Park ◽  
Sukhoon Yoon
Keyword(s):  
Gait Analysis ◽  
Stance Phase ◽  
Statistical Parametric Mapping ◽  
Swing Phase ◽  
Measurement Unit ◽  
Continuous Variables ◽  
Parametric Mapping ◽  
Inertial Measurement ◽  
Ankle Joints ◽  
Measurement Units

Inertial measurement units (IMUs) are possible alternatives to motion-capture systems (Mocap) for gait analysis. However, IMU-based system performance must be validated before widespread clinical use. Therefore, this study evaluated the validity of IMUs using statistical parametric mapping (SPM) for gait analysis. Ten healthy males (age, 30.10 ± 3.28 years; height, 175.90 ± 5.17 cm; weight: 82.80 ± 17.15 kg) participated in this study; they were asked to walk normally on a treadmill. Data were collected during walking at the self-selected speeds (preferred speed, 1.34 ± 0.10 m/s) using both Mocap and an IMU. Calibration was performed directly before each gait measurement to minimize the IMU drift error over time. The lower-extremity joint angles of the hip, knee, and ankle were calculated and compared with IMUs and Mocap; the hip-joint angle did not differ significantly between IMUs and Mocap. There were significant differences in the discrete (max, min, and range of motion) and continuous variables (waveform: 0–100%) of the knee and ankle joints between IMUs and Mocap, particularly on the swing phase (p < 0.05). Our results suggest that IMU-based data can be used confidently during the stance phase but needs evaluation regarding the swing phase in gait analysis.

Design of a Clutch–Spring Knee Exoskeleton for Running

2014 ◽  
Vol 8 (3) ◽  
Author(s):  
Grant Elliott ◽  
Andrew Marecki ◽  
Hugh Herr
Keyword(s):  
Control Strategy ◽  
Stance Phase ◽  
Planetary Gear ◽  
Knee Extension ◽  
Swing Phase ◽  
Gear Transmission ◽  
Sensory Inputs ◽  
Peak Knee ◽  
Low Mass ◽  
And Control

Because the leg is known to exhibit springlike behavior during the stance phase of running, several exoskeletons have attempted to place external springs in parallel with some or all of the leg during stance, but these designs have failed to permit natural kinematics during swing. To this end, a parallel-elastic exoskeleton is presented that introduces a clutch to disengage the parallel leg-spring and thereby not constrain swing-phase movements of the biological leg. A custom interference clutch with integrated planetary gear transmission, made necessary by the requirement for high holding torque but low mass, is presented and shown to withstand up to 190 N·m at 1.8 deg resolution with a mass of only 710 g. A suitable control strategy for locking the clutch at peak knee extension is also presented, where only an onboard rate gyroscope and exoskeletal joint encoder are employed as sensory inputs. Exoskeletal electromechanics, sensing, and control are shown to achieve design critieria necessary to emulate biological knee stiffness behaviors in running.

scholarly journals Sex difference in hip adduction during the stance phase of running: A swing phase problem?

2020 ◽  
Author(s):  
Jia Liu ◽  
George J Salem ◽  
Christopher M Powers
Keyword(s):  
Sex Differences ◽  
Motion Capture ◽  
Stance Phase ◽  
Linear Regression Analysis ◽  
Swing Phase ◽  
Heel Strike ◽  
Motion Capture System ◽  
Phase Problem ◽  
The Relationship ◽  
3D Motion Capture

ABSTRACTPurposeThe purpose of the current study was to: 1) evaluate sex differences in peak hip adduction during the late swing and stance phases of running and 2) determine if peak hip adduction during late swing is predictive of peak hip adduction during stance.Methods15 female and 16 male heel strike runners ran over ground at a speed of 4 m/s. Hip joint kinematics during running were quantified using a 3D motion capture system. Sex differences in peak hip adduction during the late swing and stance phases were compared using independent sample t-tests. Linear regression analysis was used to determine the relationship between late swing and stance phase hip adduction.ResultsCompared to males, females exhibited significantly greater peak hip adduction during both the late swing (8.5 ± 2.6 vs 6.1 ± 2.8°, p = 0.019) and stance phases of running (13.3 ± 4.2 vs 9.6 ± 3.4°, p = 0.011). Furthermore, late swing peak hip adduction was predictive of subsequent stance phase peak hip adduction (r = 0.63, p < 0.001).ConclusionSex differences in hip adduction during stance are influenced in part by late swing phase hip adduction. Further studies are needed to identify potential causes of excessive hip adduction during the late swing phase of running.

scholarly journals Kinematic Comparison between Medially Congruent and Posterior-Stabilized Third-Generation TKA Designs

2021 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
Stefano Ghirardelli ◽  
Jessica L. Asay ◽  
Erika A. Leonardi ◽  
Tommaso Amoroso ◽  
Thomas P. Andriacchi ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Knee Kinematics ◽  
Primary Total Knee Arthroplasty ◽  
Flexion Angle ◽  
Heel Strike ◽  
Third Generation ◽  
Knee Flexion Angle ◽  
Posterior Stabilized ◽  
Rotational Angle ◽  
Peak Knee

Background: This study compares knee kinematics in two groups of patients who have undergone primary total knee arthroplasty (TKA) using two different modern designs: medially congruent (MC) and posterior-stabilized (PS). The aim of the study is to demonstrate only minimal differences between the groups. Methods: Ten TKA patients (4 PS, 6 MC) with successful clinical outcomes were evaluated through 3D knee kinematics analysis performed using a multicamera optoelectronic system and a force platform. Extracted kinematic data included knee flexion angle at heel-strike (KFH), peak midstance knee flexion angle (MSKFA), maximum and minimum knee adduction angle (KAA), and knee rotational angle at heel-strike. Data were compared with a group of healthy controls. Results: There were no differences in preferred walking speed between MC and PS groups, but we found consistent differences in knee function. At heel-strike, the knee tended to be more flexed in the PS group compared to the MC group; the MSKFA tended to be higher in the PS group compared to the MC group. There was a significant fluctuation in KAA during the swing phase in the PS group compared to the MC group, PS patients showed a higher peak knee flexion moment compared to MC patients, and the PS group had significantly less peak internal rotation moments than the MC group. Conclusions: Modern, third-generation TKA designs failed to reproduce normal knee kinematics. MC knees tended to reproduce a more natural kinematic pattern at heel-strike and during axial rotation, while PS knees showed better kinematics during mid-flexion.

scholarly journals Quadriceps Strength Symmetry Does Not Modify Gait Mechanics After Anterior Cruciate Ligament Reconstruction, Rehabilitation, and Return-to-Sport Training

2020 ◽  
pp. 036354652098007
Author(s):  
Elanna K. Arhos ◽  
Jacob J. Capin ◽  
Thomas S. Buchanan ◽  
Lynn Snyder-Mackler
Keyword(s):  
Knee Flexion ◽  
Cruciate Ligament ◽  
Return To Sport ◽  
Quadriceps Muscle ◽  
Quadriceps Strength ◽  
Flexion Angle ◽  
Knee Flexion Angle ◽  
Sport Training ◽  
Gait Biomechanics ◽  
Peak Knee

Background: After anterior cruciate ligament (ACL) reconstruction (ACLR), biomechanical asymmetries during gait are highly prevalent, persistent, and linked to posttraumatic knee osteoarthritis. Quadriceps strength is an important clinical measure associated with preoperative gait asymmetries and postoperative function and is a primary criterion for return-to-sport clearance. Evidence relating symmetry in quadriceps strength with gait biomechanics is limited to preoperative and early rehabilitation time points before return-to-sport training. Purpose/Hypothesis: The purpose was to determine the relationship between symmetry in isometric quadriceps strength and gait biomechanics after return-to-sport training in athletes after ACLR. We hypothesized that as quadriceps strength symmetry increases, athletes will demonstrate more symmetric knee joint biomechanics, including tibiofemoral joint loading during gait. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Of 79 athletes enrolled in the ACL-SPORTS Trial, 76 were participants in this study after completing postoperative rehabilitation and 10 return-to-sport training sessions (mean ± SD, 7.1 ± 2.0 months after ACLR). All participants completed biomechanical walking gait analysis and isometric quadriceps strength assessment using an electromechanical dynamometer. Quadriceps strength was calculated using a limb symmetry index (involved limb value / uninvolved limb value × 100). The biomechanical variables of interest included peak knee flexion angle, peak knee internal extension moment, sagittal plane knee excursion at weight acceptance and midstance, quadriceps muscle force at peak knee flexion angle, and peak medial compartment contact force. Spearman rank correlation (ρ) coefficients were used to determine the relationship between limb symmetry indexes in quadriceps strength and each biomechanical variable; alpha was set to .05. Results: Of the 76 participants, 27 (35%) demonstrated asymmetries in quadriceps strength, defined by quadriceps strength symmetry <90% (n = 23) or >110% (n = 4) (range, 56.9%-131.7%). For the biomechanical variables of interest, 67% demonstrated asymmetry in peak knee flexion angle; 68% and 83% in knee excursion during weight acceptance and midstance, respectively; 74% in internal peak knee extension moment; 57% in medial compartment contact force; and 74% in quadriceps muscle force. There were no significant correlations between quadriceps strength index and limb symmetry indexes for any biomechanical variable after return-to-sport training ( P > .129). Conclusion: Among those who completed return-to-sport training after ACLR, subsequent quadriceps strength symmetry was not correlated with the persistent asymmetries in gait biomechanics. After a threshold of quadriceps strength is reached, restoring strength alone may not ameliorate gait asymmetries, and current clinical interventions and return-to-sport training may not adequately target gait.

scholarly journals Relationship between Quadriceps Tendon Young’s Modulus and Maximum Knee Flexion Angle in the Swing Phase of Gait in Patients with Severe Knee Osteoarthritis

Medicina ◽  
2020 ◽  
Vol 56 (9) ◽  
pp. 437
Author(s):  
Bungo Ebihara ◽  
Takashi Fukaya ◽  
Hirotaka Mutsuzaki
Keyword(s):  
Young’S Modulus ◽  
Gait Speed ◽  
Knee Flexion ◽  
Young's Modulus ◽  
Quadriceps Tendon ◽  
Swing Phase ◽  
Flexion Angle ◽  
Knee Flexion Angle ◽  
Knee Oa ◽  
Analysis System

Background and objectives: Decreased knee flexion in the swing phase of gait can be one of the causes of falls in severe knee osteoarthritis (OA). The quadriceps tendon is one of the causes of knee flexion limitation; however, it is unclear whether the stiffness of the quadriceps tendon affects the maximum knee flexion angle in the swing phase. The purpose of this study was to clarify the relationship between quadriceps tendon stiffness and maximum knee flexion angle in the swing phase of gait in patients with severe knee OA. Materials and Methods: This study was conducted from August 2018 to January 2020. Thirty patients with severe knee OA (median age 75.0 (interquartile range 67.5–76.0) years, Kellgren–Lawrence grade: 3 or 4) were evaluated. Quadriceps tendon stiffness was measured using Young’s modulus by ShearWave Elastography. The measurements were taken with the patient in the supine position with the knee bent at 60° in a relaxed state. A three-dimensional motion analysis system measured the maximum knee flexion angle in the swing phase. The measurements were taken at a self-selected gait speed. The motion analysis system also measured gait speed, step length, and cadence. Multiple regression analysis by the stepwise method was performed with maximum knee flexion angle in the swing phase as the dependent variable. Results: Multiple regression analysis identified quadriceps tendon Young’s modulus (standardized partial regression coefficients [β] = −0.410; p = 0.013) and gait speed (β = 0.433; p = 0.009) as independent variables for maximum knee flexion angle in the swing phase (adjusted coefficient of determination = 0.509; p < 0.001). Conclusions: Quadriceps tendon Young’s modulus is a predictor of the maximum knee flexion angle. Clinically, decreasing Young’s modulus may help to increase the maximum knee flexion angle in the swing phase in those with severe knee OA.

scholarly journals Ankle Angle Prediction Using a Footwear Pressure Sensor and a Machine Learning Technique

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3790
Author(s):  
Zachary Choffin ◽  
Nathan Jeong ◽  
Michael Callihan ◽  
Savannah Olmstead ◽  
Edward Sazonov ◽  
...  
Keyword(s):  
Machine Learning ◽  
Pressure Sensor ◽  
Learning Algorithm ◽  
Flexible Substrate ◽  
Ankle Injuries ◽  
Sensor System ◽  
Measurement Unit ◽  
K Nearest Neighbor ◽  
Machine Learning Technique ◽  
Learning Technique

Ankle injuries may adversely increase the risk of injury to the joints of the lower extremity and can lead to various impairments in workplaces. The purpose of this study was to predict the ankle angles by developing a footwear pressure sensor and utilizing a machine learning technique. The footwear sensor was composed of six FSRs (force sensing resistors), a microcontroller and a Bluetooth LE chipset in a flexible substrate. Twenty-six subjects were tested in squat and stoop motions, which are common positions utilized when lifting objects from the floor and pose distinct risks to the lifter. The kNN (k-nearest neighbor) machine learning algorithm was used to create a representative model to predict the ankle angles. For the validation, a commercial IMU (inertial measurement unit) sensor system was used. The results showed that the proposed footwear pressure sensor could predict the ankle angles at more than 93% accuracy for squat and 87% accuracy for stoop motions. This study confirmed that the proposed plantar sensor system is a promising tool for the prediction of ankle angles and thus may be used to prevent potential injuries while lifting objects in workplaces.

scholarly journals Developmental constraints of quadrupedal coordination across crawling styles in human infants

2012 ◽  
Vol 107 (11) ◽  
pp. 3050-3061 ◽  
Author(s):  
Susan K. Patrick ◽  
J. Adam Noah ◽  
Jaynie F. Yang
Keyword(s):  
Nervous System ◽  
Stance Phase ◽  
Swing Phase ◽  
Interlimb Coordination ◽  
Young Age ◽  
Developmental Constraints ◽  
Human Infants ◽  
Coordination Patterns ◽  
Duration Of Cycle ◽  
Developing Nervous System

Human infants can crawl using several very different styles; this diversity appears at first glance to contradict our previous findings from hands-and-knees crawling, which suggested that there were strict limitations on coordination, imposed either mechanically or by the developing nervous system. To determine whether coordination was similarly restricted across crawling styles, we studied free crawling overground in 22 infants who used a number of different locomotor strategies. Despite the wide variety in the use of individual limbs and even the number of limbs used, the duration of the stance phase increased with duration of cycle, whereas the duration of the swing phase remained more constant. Additionally, all infants showed organized, rhythmic interlimb coordination. Alternating patterns (e.g., trotlike) predominated (86% of infants). Alternatively, yet much less frequently, all limbs used could work in synchrony (14% of infants). Pacelike patterns were never observed, even in infants that crawled with the belly remaining in contact with the ground so that stability was not a factor. To explore the robustness of the interlimb coordination, a perturbation that prolonged swing of the leg was imposed on 14 additional infants crawling on hands and knees overground or on the treadmill. The perturbation led to a resetting of the crawling pattern, but never to a change in the coordination of the limbs. The findings concur with those regarding other infant animals, together suggesting that the nervous system itself limits the coordination patterns available at a young age.

Central connections of sensory neurones from a hair plate proprioceptor in the thoraco-coxal joint of the locust.

1995 ◽  
Vol 198 (7) ◽  
pp. 1589-1601 ◽  
Author(s):  
F Kuenzi ◽  
M Burrows
Keyword(s):  
Stance Phase ◽  
Swing Phase ◽  
Motor Neurone ◽  
Sensory Neurone ◽  
Sensory Neurones ◽  
Selective Stimulation ◽  
Basal Joint ◽  
Motor Neurones ◽  
Individual Motor ◽  
Stimulation Of

The hair plate proprioceptors at the thoraco-coxal joint of insect limbs provide information about the movements of the most basal joint of the legs. The ventral coxal hair plate of a middle leg consists of group of 10-15 long hairs (70 microns) and 20-30 short hairs (30 microns). The long hairs are deflected by the trochantin as the leg is swung forward during the swing phase of walking, and their sensory neurones respond phasically during an imposed deflection and tonically if the deflection is maintained. Selective stimulation of the long hairs elicits a resistance reflex that rotates the coxa posteriorly and is similar to that occurring at the transition from the swing to the stance phase of walking. The motor neurones innervating the posterior rotator and adductor coxae muscles are excited, and those to the antagonistic anterior rotator muscle are inhibited. By contrast, selective stimulation of the short hairs leads only to a weak inhibition of the anterior rotator. The excitatory effects of the long hairs are mediated, in part, by direct connections between their sensory neurones and particular motor neurones. A spike in a sensory neurone elicits a short-latency depolarising postsynaptic potential (PSP) in posterior rotator and adductor motor neurones whose amplitude is enhanced by hyperpolarising current injected into the motor neurone. When the calcium in the saline is replaced with magnesium, the amplitude of the PSP is reduced gradually, and not abruptly as would be expected if an interneurone were interposed in the pathway. Several sensory neurones from long hairs converge to excite an individual motor neurone, evoking spikes in some motor neurones. The projections of the sensory neurones overlap with some of the branches of the motor neurones in the lateral association centre of the neuropile. It is suggested that these pathways would limit the extent of the swing phase of walking and contribute to the switch to the stance phase in a negative feedback loop that relieves the excitation of the hairs by rotating the coxa backwards.

scholarly journals ROLE OF HAMSTRING MUSCLES IN KNEE JOINT STABILITY PROVIDING AND INJURY PREVENTION

2016 ◽  
Vol 3 ◽  
pp. 522
Author(s):  
Inese Pontaga
Keyword(s):  
Stance Phase ◽  
Knee Extension ◽  
Swing Phase ◽  
Joint Stability ◽  
Distance Runners ◽  
Leg Extension ◽  
Hamstring Muscles ◽  
Extreme Extension ◽  
Torque Values

The aim of our investigation was to determine the ratio of maximal torque values and the torques in the certain positions of range of movements (ROM) between hamstring (H) and quadriceps femoris (Q) muscles at medium and high velocity of movement in concentric (CC) and eccentric (ECC) action of hamstring muscles. The knee muscles of 15 amateur female short and middle distance runners were tested by the dynamometer system in the isokinetic movements with the angular velocity of 90º/s and 240º/s in CC and at the velocity of 90º/s in ECC H/ CC Q muscles contractions. The torque values produced by the muscles are detected at the different angular positions of the ROM with the step of 10º. The ratios of H/ Q muscles torques are calculated. The H/Q muscles maximal torques ratio is 0.51 ± 0.13 at the velocity of 90º/s in CC and 0.60 ± 0.09 in ECC H/ CC Q muscles contractions, and 0.59 ± 0.09 CC at the velocity of 240º/s. The H/Q maximal torques ratio and this ratio in the knee extreme extension and flexion at the ECC contraction of H is higher due to greater torques produced by the H in comparison with Q muscle. The H must be stronger to decelerate the thigh and lower leg extension in the late swing phase of running and to extend the hip in early stance phase to provide powerful sprint running and prevent the knee and H injury. The H/Q muscles torques ratio in extended knee positions are similar in medium (90º/s) and fast (240º/s) velocity of motions because CC action of H muscles cannot prevent extreme knee extension.

Sign in / Sign up

Export Citation Format

Share Document