Seungbum Koo

• Ph.D.
• Professor (Associate) at Korea Advanced Institute of Science and Technology

Purpose The kinematic benefits of arm swing during running for upper body stability have been previously investigated, while its role in metabolic energy efficiency remains controversial. To address this, this study aimed to test the hypothesis that active arm swing during running reduces both torso angular motion around the longitudinal axis and m...

Purpose: Statistical shape and intensity models (SSIMs) and digitally reconstructed radiographs (DRRs) were introduced for non-rigid 2D-3D registration and skeletal geometry/density reconstruction studies. The computation of DRRs takes most of the time during registration or reconstruction. The goal of this study is to propose a particle-based met...

Background Physical skeletal loading can affect the bone mineral density (BMD). This study investigated the association between BMD and dynamic foot pressure during gait. Methods A total of 104 patients (mean age, 62.6 ± 12.4 years; 23 male and 81 female) who underwent dual x-ray absorptiometry and pedobarography were included. BMD values of the l...

The energy efficiency theory of human bipedal locomotion has been widely accepted as a neuro-musculoskeletal control method. However, coactivation of agonist and antagonist muscles in the lower limb has been observed during various limb movements, including walking. The emergence of this coactivation cannot be explained solely by the energy efficie...

Objectives The effects of foot deformities and corrections on the ankle joint without osteoarthritis has received little attention. This study aimed to investigate the effect of flatfoot correction on the ankle joint of patients without osteoarthritis. Methods Thirty-five patients (24 men and 11 women; mean age 17.5 years) who underwent lateral co...

Although studies have demonstrated the potential of using a single inertial sensor for walking and running motion prediction, further analysis of sensor position and training dataset size is required. This study investigates the accuracies and two types of uncertainties associated with using a single virtual accelerometer for whole-body motion pred...

Background For anterolateral rotatory instability as a result of secondary soft tissue injuries in anterior cruciate ligament (ACL)-deficient knees, there is increasing interest in secondary stabilizers to prevent internal rotation (IR) of the tibia. Purpose To determine which secondary stabilizer is more important in anterolateral rotatory instab...

Background: Pes planovalgus (PV) deformity accounts for lever arm dysfunction and compromises gait in patients with cerebral palsy (CP). However, the association between ankle power generation and radiographic indices is not yet understood. We aimed to investigate the association between ankle power and radiographic indices during gait in patients...

Foot deformities in patients with flexible flatfeet, such as the flattened medial arch and hindfoot valgus, affect the force distribution around the tibiotalar joint during walking and increase the risk of secondary injuries. In this study, we developed a multi-segment foot model that could calculate the dynamics around the tibiotalar joint and inv...

Treadmills are widely used in rehabilitation and gait analysis. However, previous studies have reported differences in terms of kinematics and kinetics between treadmill and overground walking due to physical and psychological factors. The aim of this study was to analyze gait differences due to only the physical factors of treadmill walking. Walki...

Injuries in the anterior cruciate ligament (ACL), including partial tear and lengthening of the ACL, change the dynamic function of the knee. However, there is a lack of information on the effect of ACL partial tear on knee kinematics during walking. This study aimed to investigate the effects of different levels of ACL injuries on the knee stabili...

Background Radiographic factors estimate the state of the static knee joint, and it is questionable how well these parameters reflect the dynamic knee condition. The external knee adduction moment (KAM) during gait is known to be a kinetic variable contributing to osteoarthritis progression. This study aims to investigate the effects of static radi...

The gait kinematics of an individual is affected by various factors, including age, anthropometry, gender, and disease. Detecting anomalous gait features aids in the diagnosis and treatment of gait-related diseases. The objective of this study was to develop a machine learning method for automatically classifying five anomalous gait features, i.e.,...

Abnormal foot kinematics is observed in flatfoot subjects with postural foot deformity. We aimed to investigate joint instability in flatfoot subjects by analyzing the abnormal rotational position and speed of their joints while walking. Five flatfoot subjects participated in our study. Three-dimensional motions of the tibia, talus, calcaneus, navi...

Gait, the style of human walking, has been studied as a behavioral characteristic of an individual. Several studies have utilized gait to identify individuals with the aid of machine learning and computer vision techniques. However, there is a lack of studies on the nature of gait, such as the identification power or the uniqueness. This study aims...

Background Kinetic data obtained during gait can be used to clarify the biomechanical pathogenesis of osteoarthritis of the lower extremity. This study aimed to investigate the difference in ankle varus moment between the varus angulation and medial translation types of medial ankle osteoarthritis, and to identify the radiographic measurements asso...

This study was to analyze intrasubject radiographic progression of the hallux valgus deformity by comparing the mildly and severely affected sides in patients with bilateral asymmetric hallux valgus in the whole group as well as the metatarsus adductus and the non-metatarsus adductus subgroups. A total of 186 patients with bilateral asymmetrical ha...

Posterior tibial tendon integrity is an important consideration when treating adult-acquired flatfoot caused by posterior tibial tendon dysfunction. The condition of this tendon traditionally has been evaluated with ultrasonography or magnetic resonance imaging, but recent advances in radiography have increased the resolution of radiographic soft t...

Plantar soft tissue stiffening in diabetes leads to a risk of developing ulcers. There are relatively few studies providing methods for quantifying the mechanical properties of skin and fat in the plantar tissue of diabetic patients. Previous studies used linear or non-linear single layer deformable models or linear multi-layer models. This study a...

The attachment locations of anterior cruciate ligament (ACL) grafts during reconstruction have been reported to influence knee joint function. However, there are controversial opinions on femoral ACL attachment locations for restoring normal knee kinematics. The knee stability and ACL force by different ACL attachment locations could be predicted u...

Category Ankle Introduction/Purpose Insufficient bony coverage surrounding the talus could cause considerable mechanical ankle instability, whereas excessive bony coverage could cause bone contusion at the time of injury and subsequent osteochondral lesions of the talus (OLT). This study aimed to investigate the relationship between radiographic l...

Category Trauma Introduction/Purpose Long-term usage of bisphosphonate can severely suppress bone turnover and alter bone mechanical properties, thereby resulting in atypical fractures that mainly occur at the femur.We present a rare case of suspicious atypical fracture of the metatarsal bone. Methods A 63-year-old woman presented to our clinic w...

Category Midfoot/Forefoot Introduction/Purpose This study aimed to investigate the pedobarographic characteristics of tarsometatarsal instability and to identify factors associated with pedobarographic first tarsometatarsal instability in patients with hallux valgus deformity. Methods Fifty-seven patients (mean age, 59.7 years; standard deviation...

Background Insufficient or excessive bony constraint surrounding the talus might contribute to the occurrence of ligamentous injury or bone contusion, respectively, at the time of ankle inversion injuries. This study aimed to investigate the relationship between radiographic lateral ankle instability and osteochondral lesions of the talus (OLT) fol...

[This corrects the article DOI: 10.1371/journal.pone.0220073.].

The kinematics of the human foot complex have been investigated to understand the weight bearing mechanism of the foot. This study aims to investigate midtarsal joint locking during walking by noninvasively measuring the movements of foot bones using a high-speed bi-planar fluoroscopic system. Eighteen healthy subjects volunteered for the study; th...

Background: Subtalar fusion usually leads to a satisfactory clinical outcome by eliminating the motion of the subtalar joint but can cause an aggravation of osteoarthritis after the subtalar fusion. Previous studies have investigated the effect of subtalar fusion in static testing using cadaver limbs, but there was no evidence of an aggravation of...

Background This study aimed to investigate the effects of walking speed and slope on foot pressure changes in young healthy adults. Methods Twenty young healthy adults (mean age 22.4 years, SD 1.2 years; 10 male and 10 female) participated in the study. Dynamic pedobarographic data during treadmill walking were obtained for combinations of three d...

Background: This study aimed to investigate the pedobarographic characteristics of tarsometatarsal instability and to identify factors associated with pedobarographic first tarsometatarsal instability in patients with hallux valgus. Methods: Fifty-seven patients (mean age, 59.7 years; standard deviation, 11.4 years; 6 men and 51 women) with a ha...

Accurate joint kinematics plays an important role in estimating joint kinetics in musculoskeletal simulations. Biplanar fluoroscopic (BPF) systems have been introduced to measure skeletal kinematics with six degrees-of-freedom. The purpose of this study was to model knee kinematic coupling using knee kinematics during walking, as measured by the BP...

Intraosseous alignment of the tarsal bone has not been investigated in relation to various foot deformities. This study aimed to investigate three-dimensional computed tomography (3D CT) talar morphology in children with idiopathic and neuromuscular pes planovalgus. Eleven children [nine boys, two girls; mean (SD) age: 10.5 (2.8) years] with idiopa...

Human musculoskeletal models have revealed the general patterns of muscle recruitment during daily activities. Nonetheless, the consistency of dynamics calculations from different musculoskeletal simulation packages is not well understood. The objective of this study was to understand the effect of the simulation solver and simulation model on the...

Objectives The objective of this study was to quantify the relative movement between the articular surfaces in the tibiotalar and subtalar joints during normal walking in asymptomatic individuals. Methods 3D movement data of the ankle joint complex were acquired from 18 subjects using a biplanar fluoroscopic system and 3D-to-2D registration of bone...

Human motion during walking provides biometric information which can be utilized to quantify the similarity between two persons or identify a person. The purpose of this study was to develop a method for identifying a person using their walking motion when another walking motion under different conditions is given. This type of situation occurs fre...

Objectives The objective of this study was to quantify the relative movement between the articular surfaces in the tibiotalar and subtalar joints during normal walking in asymptomatic individuals. Methods 3D movement data of the ankle joint complex were acquired from 18 subjects using a biplanar fluoroscopic system and 3D-to-2D registration of bon...

Category Basic Sciences/Biologics Introduction/Purpose Although pedobarographic measurement is increasingly used for clinical and research purposes, relatively few published studies have investigated regarding effects of walking speed and slope. This study examined pedobarographic findings in young healthy adults with regard to different walking s...

Background Although pedobarographic measurement is increasingly used for clinical and research purposes, relatively few published studies have investigated normative data. This study examined pedobarographic findings in young healthy adults with regard to sex-related differences and correlations among measurement indices. Methods Twenty young heal...

Human gait reflects biomedical conditions and thus can potentially be used for identification. With the increasing utility of CCTVs for surveillance, there have been various attempts to recognize persons using gait image sequences from a single camera. We investigated the accuracy of estimating body segment lengths and joint angles during gait calc...

The net force and moment of a joint have been widely used to understand joint disease in the foot. Meanwhile, it does not reflect the physiological forces on muscles and contact surfaces. The objective of the study is to estimate active moments by muscles, passive moments by connective tissues and joint contact forces in the foot joints during walk...

Background: This study aimed to investigate the radiographic measurements associated with the progression of hallux valgus during at least 2 years of follow-up. Methods: Seventy adult patients with hallux valgus who were followed for at least 2 years and underwent weightbearing foot radiography were included. Radiographic measurements included t...

Human motion has been widely analyzed for different purposes such as human motion prediction, human identification. In this study, we propose a method for human style prediction based on the 3D marker coordinate. There are 28 subjects performed walking with non-weight condition and with tote bag of 5% of body weight. The 3D motion of each subjects...

Chronic occupational lower limb injuries such as osteoarthritis require an understanding of mechanical loading conditions in joints during occupational activities. We aimed to develop a human musculoskeletal model and to estimate knee contact force and ground reaction force (GRF) simultaneously during walking and squatting. GRF and joint kinematics...

Category Ankle, Sports Introduction/Purpose We hypothesized that the bony configuration of the ankle could also be associated with ankle stress radiographs, in addition to ligament injury of the ankle. Therefore, this study aimed to investigate the relationship between bone morphology and injured ligament on imaging studies and laxity on ankle str...

Category Basic Sciences/Biologics Introduction/Purpose Although pedobarographic measurement is increasingly used for clinical and research purposes, relatively few published studies have investigated normative data. This study examined pedobarographic findings in young healthy adults with regard to sex-related differences and correlations among me...

Category Bunion, Midfoot/Forefoot Introduction/Purpose There is a lack of quantitative studies on the progression of juvenile hallux valgus deformity. Therefore, we performed this study to estimate an annual change of radiographic indices for juvenile hallux valgus. Methods We reviewed medical records of consecutive patients under the age of 15 w...

Category Ankle, Trauma Introduction/Purpose Several methods like cortical screw, Kirschner (K) wire have been used for stabilizing the Lisfranc joint. We performed this study to assess whether single dorsal plating can be used as an alternative treatment method for a Lisfranc injury. Methods Patients were followed up for more than 1 year after th...

Category Ankle, Arthroscopy, Trauma Introduction/Purpose This meta-analysis was performed to determine whether the arthroscopically assisted open reduction and internal fixation (ORIF) for ankle fractures is more beneficial than the conventional ORIF. Methods Articles in electronic medial databases were searched between March 1983 and August 2016...

Category Hindfoot Introduction/Purpose Posterior tibial tendon’s condition has traditionally been evaluated using ultrasonography or magnetic resonance imaging, but recent advancements in radiography have increased the resolution of radiographic soft tissue images. We performed this study to examined whether the posterior tibial tendon could be sc...

Category Bunion Introduction/Purpose There have been few longitudinal studies regarding hallux valgus deformity. This retrospective study aimed to investigate the radiographic measurements associated with the progression of hallux valgus deformity during at least two years of follow-up. Methods Seventy adult patients (mean age, 58.0 years; standa...

Introduction: This meta-analysis was performed to determine whether the arthroscopically assisted open reduction and internal fixation (ORIF) for ankle fractures is more beneficial than the conventional ORIF. Methods: Articles in electronic medial databases were searched between March 1983 and August 2016, including Pubmed and SCOPUS. We include...

Artificial neural network (ANN) has been applied to identify the people with pathological gait based on different kind of features such as ground reaction force, hip-knee joint angles or marker coordinate data. In this research, we propose to use Fourier components of maker coordinate data as inputs of an ANN in order to perform the classification...

This study aimed to investigate the relationship between bone morphology and injured ligaments on imaging studies and laxity on ankle stress radiographs in patients with lateral ankle instability. In total, 115 patients who had undergone ankle MRI, ankle radiography, and stress radiography were included. Distal tibial articular surface angle, bimal...

The objective of this study was to develop a musculoskeletal spine model that allows relative movements in the thoracic spine for calculation of intra-discal forces in the lumbar and thoracic spine. The thoracic part of the spine model was composed of vertebrae and ribs connected with mechanical joints similar to anatomical joints. Three different...

Human dynamic models have been used to estimate joint kinetics during various activities. Kinetics estimation is in demand in sports and clinical applications where data on external forces, such as the ground reaction force (GRF), are not available. The purpose of this study was to estimate the GRF during gait by utilizing distance- and velocity-de...

Joint contact forces measured with instrumented knee implants have not only revealed general pattern of joint loading but also showed individual variations that could be due to differences in anatomy and joint kinematics. Musculoskeletal human models for dynamics simulation have been utilized to understand body kinetics including joint moments, mus...

Purpose: To evaluate dynamic three-dimensional (3D) kinematic properties of the anterior cruciate ligament (ACL)-insufficient knees and healthy contralateral knees in awake patients during the Lachman test using biplane fluoroscopy. Materials and methods: Ten patients with unilateral ACL-insufficient knees and healthy contralateral knees were en...

Gross motion of the ankle joint complex (AJC) is a summation of the ankle and subtalar joints. Although AJC kinematics have been widely used to evaluate the function of the AJC, the coordinated movements of the ankle and subtalar joints are not well understood. The purpose of this study was to accurately quantify the individual kinematics of the an...

Ankle injuries associated with tibial shaft fractures can cause postoperative ankle pain and stiffness even when satisfactory bony union has been achieved. Although several previous studies have described these injuries, they have not been clearly defined or classified in terms of ankle injury type or need for surgical fixation. Seventy-one consecu...

Background Moderate joint loading is essential to maintain cartilage health and function but the impact of immobilization on articular cartilage in healthy individuals is not well understood. One established biomarker for monitoring cartilage metabolism in relation to joint degeneration is cartilage oligomeric matrix protein (COMP)1 which is sensit...

Anatomical landmarks and bony features are frequently used in biomechanical and surgical applications. The purpose of this study was to develop a local region matching-based anatomical landmark prediction method. A reference femur model with anatomical landmarks and a surface division map was prepared. Initial registration between the reference fem...

Background: Injury mechanism and the amount of force are important factors determining whether a fracture or sprain occurs at the time of an ankle inversion injury. However, the anatomical differences between the ankle fracture and sprain have not been investigated sufficiently. This study was performed to investigate whether an anatomical predisp...

Kinetic analysis of walking requires joint kinematics and ground reaction force (GRF) measurement, which are typically obtained from a force plate. GRF is difficult to measure in certain cases such as slope walking, stair climbing, and track running. Nevertheless, estimating GRF continues to be of great interest for simulating human walking. The pu...

Computer-aided manufacturing is widely used to create products from computer-aided design (CAD) models. The different characteristics of each manufacturing process can lead to product defects. Therefore, it is necessary to inspect the shape and dimensions of a manufactured product against the original CAD model for quality assurance. While the conv...

A method for musculoskeletal tissue segmentation used in magnetic resonance imaging (MRI) is provided. MRI image data is collected using at least two different contrast mechanisms. Voxel values from data from each contrast mechanism are used as elements of a feature vector. The feature vector is compared with classification boundaries to classify m...

Accurate quantification of bone morphology is important for monitoring the progress of bony deformation in patients with cerebral palsy. The purpose of the study was to develop an automatic bone morphology measurement method using one or two radiographs. The study focused on four morphologic measurements-neck-shaft angle, femoral anteversion, shaft...

Anatomical landmarks on bones play important roles in musculoskeletal simulations and surgical planning. This study develops an anatomically deformable model of the femur to predict bone landmarks automatically and quantifies its prediction accuracy. Forty-three angiographic computed tomography (CT) images of femurs were collected and 14 bone landm...

The knee adduction moment has been reported to play important roles in predicting the outcome of high tibial osteotomy [1] and progression of knee osteoarthritis [2]. The knee adduction moment is an extrinsic force calculated through the inverse dynamics method when joint kinematics along with all external forces such ground reaction force (GRF)...

Purpose It is reported that the length of the posterior cruciate ligament (PCL) fibres increases as the knee flexes, and the magnitude of the length change reaches up to 9.8 mm throughout the range of motion, which exceeds the range of failure strain. Therefore, we postulated that a compensatory mechanism must be recruited to overcome this large st...

The purpose of this study was to evaluate the isometry of an anatomic femoral tunnel and anterior tibial tunnel positions. Tibial tunnels were made at 2 different locations in 10 cadaveric knees: the conventional tunnel and a more anterior position. Three-dimensional computed tomography (CT) scanning was then performed at 0°, 30°, 60°, 90°, and 120...

To evaluate the isometry of different tunnel positions in posterolateral corner (PLC) reconstruction using 3-dimensional computed tomography. In 10 fresh-frozen cadaveric knees, fibular tunnels were made from the anterodistal surface of the fibular neck to the posteroproximal fibular tip. Tibial tunnels were made from just medial to the Gerdy tuber...

There is a growing interest in three-dimensional computed tomography (3D-CT) as a research tool for the study of bone, joint anatomy, and kinematics. However, when CT data are processed and handled manually using image processing programs to yield 3D image and coordinate value, systematic and random errors should be validated. We evaluated the accu...

There are many situations in sports when external forces such as ground reaction force are unobtainable. Musculoskeletal kinetics including joint moments can be calculated when all external force information including ground reaction force are provided. In this study, we developed a simulation method that can predict the center of pressure on the f...

The menisci play an important role in load distribution, load bearing, joint stability, lubrication, and proprioception. Partial meniscectomy has been shown to result in changes in the kinematics and kinetics at the knee during gait that can lead to progressive meniscal degeneration. This study examined changes in the strains within the menisci ass...

A pose estimation process from medical images is calculating locations and orientations of objects obtained from Computed Tomography (CT) volume data utilizing X-ray images from two directions. In this process, digitally reconstructed radiograph (DRR) images of spatially transformed objects are generated and compared to X-ray images repeatedly unti...

The regional adaptation of knee cartilage morphology to the kinematics of walking has been suggested as an important factor in the evaluation of the consequences of alteration in normal gait leading to osteoarthritis. The purpose of this study was to investigate the association of spatial cartilage thickness distributions of the femur and tibia in...

to create a custom-shaped graft through 3D tissue shape reconstruction and rapid-prototype molding methods using MRI data, and to test the accuracy of the custom-shaped graft against the original anatomical defect. An iatrogenic defect on the distal femur was identified with a 1.5 Tesla MRI and its shape was reconstructed into a three-dimensional (...

Purpose to create a custom-shaped graft through 3D tissue shape reconstruction and rapid-prototype molding methods using MRI data, and to test the accuracy of the custom-shaped graft against the original anatomical defect. Methods An iatrogenic defect on the distal femur was identified with a 1.5 Tesla MRI and its shape was reconstructed into a th...

Cartilage morphology change is an important biomarker for the progression of osteoarthritis. The purpose of this study was to assess the accuracy of in vivo cartilage thickness measurements from MR image-based 3D cartilage models using a laser scanning method and to test if the accuracy changes with cartilage thickness. Three-dimensional tibial car...

Objective: MRI is the most accurate noninvasive method available to diagnose disorders of articular cartilage. Conventional 2D and 3D approaches show changes in cartilage morphology. Faster 3D imaging methods with isotropic resolution can be reformatted into arbitrary planes for improved detection and visualization of pathology. Unique contrast me...

To test the hypotheses that 1) 14-days of immobilization of young healthy subjects using a 6 degrees -"head-down-tilt-bed-rest"-model (6 degrees -HDT) would reduce cartilage thickness in the knee and serum Cartilage oligometric matrix protein (COMP) concentration and 2) isolated whole body vibration training would counteract the bed rest effects. T...

The response of healthy and diseased cartilage of the knee to the mechanics of walking is examined, with the goal of providing insight into the relationship between the kinematics and kinetics of the knee during walking and the maintenance of cartilage health. The combination of information from three-dimensional thickness models of cartilage deriv...

Introduction Aging is one of the leading risk factors for osteoarthritis [1]. Proteoglycan, one of the major components of articular cartilage, undergoes loss and structural changes with aging [2]. Proteoglycan has a negative fixed charge density, which is balanced by positively charged sodium in the cartilage. Imaging of cartilage sodium is a pote...