Hae Dong Lee

• Doctor of Philosophy
• Professor at Yonsei University

This study investigated the effects of progressively increasing voluntary activation during the stretch phase on force and work production in the stretch‐shortening cycle (SSC) of human knee extensors. Fifteen young adults performed SSCs under four stretch activation conditions: passive stretch (ST0%‐SC), feedback‐guided active stretch (ST40%‐SC an...

Introduction: Ballet-based dance training emphasizes the equal development of both legs. However, dancers often perceive differences between their legs during balance or landing. There still needs to be more consensus on the functional difference between dominant (D) and non-dominant legs (ND). Therefore, this study investigated both legs’ neuromus...

Squatting, a traditional resistance exercise classified as strength training, relies on anaerobic pathways, but its aerobic aspects remain unclear. We examined heart rate and oxygen demand during squats, exploring variations across different strength statuses. It fills gaps in understanding the cardiorespiratory effects of squatting, especially dur...

Squatting, a traditional resistance exercise classified as strength training, relies on anaerobic pathways, but its aerobic aspects remain unclear. We examined heart rate and oxygen demand during squats, exploring variations across different strength statuses. It fills gaps in understanding the cardiorespiratory effects of squatting, especially dur...

Studies for effective golf coaching such as providing a causal relationship between the address posture and golf-swing behaviors are limited. This study investigated the effects of ball position on golf-swing behaviors. Twenty professional golfers performed golf swing at five different anteroposterior (forward/backward) ball positions: reference ba...

The countermovement jump is a popular measurement modality to evaluate muscle power in sports and exercise. Muscle power is essential to achieve a high jump, yet the well-coordinated movement of the body segments, which optimizes the stretch-shortening cycle (SSC) effects, is also required. Among the proposed explanations of SSC effects, this study...

Background and Aim Although resting heart rate (RHR) is associated with prevalence and incidence of diabetes, whether it is associated with undiagnosed diabetes is still unclear. We aimed to investigate whether the RHR is associated with the prevalence of undiagnosed diabetes in a large Korean national dataset. Methods and Results The Korean Natio...

During a vertical drop jump (VDJ), the human neuromuscular system absorbs and reuses external loads applied to the lower extremity by coordinating the musculoskeletal system. This study aims to investigate the influence of the eccentric strength of the knee extensor muscles on the biomechanical factors of a VDJ. Participants were divided into two g...

PURPOSE: This study aimed to investigate the level of physical function, lower body strength, and muscle activation during various types of muscle contraction in participants with and without Parkinson’s disease (PD).METHODS: Twelve participants with PD (mean age=63.17±6.24 years) and 12 age- and sex-matched healthy adults (mean age = 58.67±6.39 ye...

This study aimed to investigate the association between domain-specific physical activity (PA) and diabetes in Korean adults. We analyzed 26,653 men and women (aged > 18 years) from the Korea National Health and Nutrition Examination Survey (2014–2018). PA was measured using a validated Global PA Questionnaire. Multivariable logistic regression was...

The purpose of this study was to investigate how the ball position along the mediolateral (M-L) direction of a golfer causes a chain effect in the ground reaction force, body segment and joint angles, and whole-body centre of mass during the golf swing. Twenty professional golfers were asked to complete five straight shots for each 5 different ball...

OBJECTIVES This study was to investigate the efficacy of intensity-controlled whole-body vibration exercise on architecture properties of the ankle plantar flexors in elderly women. METHODS A randomized-controlled design was used. Three groups were recruited in this study (VI group (n=15, 69.5±3.9 years), ET Group (n=13, 68.5±4.0 years), CON Group...

The purpose of this study was to investigate address position variables in response to changes in ball position in golfers. Eleven male professional golfers were instructed to perform their golf swing. A three-dimensional motion analysis system, with eight infrared cameras and two force platforms, was used to capture the address positions. A golf b...

This study explored the feasibility of utilizing an SWCNT-coated fabric sensor for the development of a wearable motion sensing device. The extent of variation in electric resistance of the sensor material was evaluated by varying the fiber composition of the SWCNT-coated base fabrics, attachment methods, number of layers, and sensor width and leng...

Background: It has been recognized that body fatness and mental disorders have association, however very limited evidence have proved that physical fitness and mental health have association. Relationship between physical fitness and mental health in young adults has not been fully proved. The purpose of the study was to investigate the association...

We aimed to investigate the characteristics of patients with osteoarthritis (OA), using the data of all Koreans registered in the National Health Insurance Sharing Service Database (NHISS DB), and to provide ideal alternative cutoff thresholds for alleviating OA symptoms. Patients with OA (codes M17 and M17.1–M17.9 in the Korean Standard Classifica...

This study aimed to examine whether muscle force and tendon stiffness in a muscle -tendon complex alter synchronously following 8-week whole-body vibration (WBV) training in older people. Forty older women aged 65 years and older, were randomly assigned into Control (CON, n=15) and WBV training groups (Exposure Time (ET, n=13) and Vibration Intensi...

Objective: This study aimed to examine the characteristics of joint kinematics and synchronicity of rowing motion between elite and non-elite rowers. Methods: Two elite and two non-elite rowers performed rowing strokes (3 trials, 20 strokes in each trial) at three different stroke rates (20, 30, 40 stroke/min) on two stationary rowing ergometers. T...

Objective: The purpose of this study was to investigate the acute effect of walking on high heels on the behavior of fascicle length and activation of the lower limb muscles. Methods: Twelve healthy inexperienced high heel wearers (age: 23.1?2.0yr, height: 162.4?4.9cm, weight: 54.4?8.5kg) participated in this study. They walked in high heels (7 cm)...

Objective : In order for Taekwondo athletes to perform destructive kicking performance, they are expected to have Taekwondo-specific muscle properties such as high muscle strength and power. The purpose of this study was to investigate the joint angle-dependent force-producing property of Taekwondo athletes' knee extensor muscles, which is one of t...

We propose a new method - twitch force - for estimation of the muscle behavior during voluntary contraction for assessing localized muscle fatigue. The proposed method uses the sEMG peaks as input and the measured force as output. The twitch force, which is a transfer function to generate force, was estimated during fatiguing contraction. We verifi...

Objective : The purpose of this study was to investigate difference in fascicle behavior of the medial gastrocnemius during the locomotion with varying intensities, such as gait and one-legged and two-legged vertical jumping. Methods : Six subjects (3 males and 3 females; age: 27.2?1.6yrs., body mass: 62.8?9.8kg, height: 169.6?8.5cm) performed norm...

We propose a new method to estimate joint force using a biomechanical muscle model and peaks of surface electromyography (SEMG). The SEMG measurement was carried out from the first dorsal interosseous muscle during isometric index finger abduction. The SEMG peaks were used as the input of the biomechanical muscle model which is a transfer function...

The aim of this study was to investigate the effect of resistance training with and without whole-body vibration(WBV) on the biomechanical properties of the plantarflexor in the elderly women (>60 yrs., n

The objectives of this study was to investigate the acute effects of various magnitudes of tendon strain on the mechanical properties of the human medial gastrocnemius (MG) in vivo during controlled heel-drop exercises. Seven male and seven female volunteers performed two different exercises executed one month apart: one was a heel-drop exercise on...

Tendon elasticity is an important factor affecting muscle function and thus human movements. It has been reported that the mechanical properties of tendon are adaptable to external loading condition. Based on the adaptability of muscle and tendon to external loading conditions, one can assume that there might be an optimum ratio between muscle stre...

The opposable thumb has allowed humans to develop accurate fine motor skills and has provided the same level of functionality in artificial prostheses or similar robotic hands. This study describes a real-time isometric thumb-tip force prediction that uses a biomechanical muscle model and surface electromyography signals under four different angle...

The purpose of this study was to investigate the effect of leg extension exercises performed on outdoor resistance exercise machines on knee extension muscle strength and quadriceps muscle group cross sectional area (CSA) in elderly women. Two groups were recruited for this study, including an exercise group (EG: n=13, 71.38±2.79 yrs) and a control...

It is well known that obesity increases the risk of metabolic syndrome, however, the association between fitness and metabolic syndrome risk factors among Koreans still need to be elucidated. The purpose of this study was to examine the relationship of obesity and physical fitness with metabolic syndrome risk factors among university students in ko...

The purpose of this study was to investigate the relationship among isometric and isokinetic muscle strength, lean body mass(LBM) and bone mineral density(BMD) in the elderly. Eleven males(age, 70.27±5.78yr; height, 167.36±6.68 cm; weight, 68.34±8.23 kg) and thirteen female(age, 69.77±4.13yr; height, 152.80±4.45 cm; weight, 56.86±7.40 kg) participa...

Surface electromygraphy (sEMG) provides information of the neural drive to the muscle, so muscle force estimation by sEMG is of high relevance in biomechanical studies and in bionic applications. Even though mean absolute value (MAV) has been widely used for sEMG amplitude estimation due to the probabilistic nature of sEMG, but it has been used wit...

The purpose of this study was to investigate changes in elastic properties of tendon structure of human ankle dorsiflexor following eccentric exercise. Six male subjects(age: years, height: cm, weight: kg) and three female subjects(age: years, height: cm, weight: kg) performed a single bout eccentric exercise consisting of 120 repetitions of maximu...

Three-dimensional(3D) motion analysis is a useful tool for analyzing sports performance. During the last few decades, advances in motion analysis equipment have enabled us to perform more and more complicated biomechanical analyses. Nevertheless, considering the complexity of biomechanical models and the amount of data recorded from the motion anal...

This study aimed to determine the effects of the blockage of visual feedback on joint dynamics of the lower extremity. Fifteen healthy male subjects(age: 24.1?2.3\;yr, height: 178.7?5.2\;cm, weight: 73.6?6.6\;kg) participated in this study. Each subject performed single-legged landing from a 45 cm-platform with the eyes open or closed. During the l...

The purpose of this study was to analyze the changes in kinematic and kinetic parameters of lower extremity joint according to rehabilitation period. Fourteen collegiate male athletes(age: years, height: , weight: ) and fourteen collegiate athletes on functional ankle instability(age: years, height: , weight: ) with the right leg as dominant were c...

The palmar pinch force estimation is highly relevant not only in biomechanical studies, the analysis of sports activities, and ergonomic design analyses but also in clinical applications such as rehabilitation, in which information about muscle forces influences the physician's decisions on diagnosis and treatment. Force transducers have been used...

Due to the difficulties in measurement of muscle activities and the complex musculoskeletal structure, estimations of the thumb-tip force in real time have been a challenge for controlling artificial prosthesis naturally. This study describes an isometric thumb-tip force estimation technique based on phenomenological muscle model named Hill's model...

Exposure to unaccustomed eccentric exercise causes muscle damage. Popping sarcomere theory [1] has been proposed and assumed that eccentric contraction-induced muscle damage predominantly occurs at muscle length on the descending limb of the force-length relationship. This study investigated changes in the mechanical properties following maximum ef...

Due to the complicated relationship between a muscle activation level and isometric joint torques, predicting torques under isometric conditions have been an obstacle to neuromuscular control of robots in the field of human robot interaction (HRI). This study describes the isometric torque estimation of the metacarpophalangeal (MCP) joint of a huma...

To devise a method using velocity encoded phase contrast MRI and MR-compatible dynamometry, for in vivo estimation of elastic properties of the human Achilles tendon and to assess within-session and day-to-day repeatability of this technique. Achilles tendon force and calcaneus-movement-adjusted displacement were measured during a submaximal isomet...

The objective of this study was to measure and monitor changes in Achilles tendon mechanical properties and force production capability of triceps surae muscles after 4 wk of limb suspension and 6 wk of physical rehabilitation. Five healthy volunteers underwent unilateral lower limb suspension followed by weekly physiotherapy. A velocity-encoded, p...

The purpose of this study was to investigate changes in mechanical properties of human tibialis anterior following eccentric exercise. Healthy subjects (n=12) performed 120 maximum eccentric contraction of ankle dorsiflexor. Before and 1- and 24- hour after the eccentric exercise, ankle dorsiflexion moment-angle relationships were obtained. Along w...

INTRODUCTION When an active muscle is stretched, its steady-state isometric force following stretching is greater than that of a purely isometric contraction at the same muscle length. This property is referred to as residual force enhancement (RFE) [1]. RFE has been observed in a variety of experimental preparations: single fibers, isolated muscle...

Muscle force produced by muscle fibers is transmitted to bones via tendinous structures(aponeuroses and tendon), resulting in joint(s) movement. As force-transmitting elements, mechanical behavior of aponeuroses and tendon are closely related with the function of muscle-tendon complex. The purpose of this study was to determine strain characteristi...

When an active muscle is stretched, its steady-state isometric force following stretch is greater than that of a purely isometric contraction as the corresponding muscle length, referred to as force enhancement (FE). The purpose of this study was to investigate possible effects of muscle architecture on the FE. While subject performed maximal isome...

PURPOSE Elucidation of structure and function relationship inherent in the musculoskeletal system requires accurate tracking of muscle tissue in vivo. Using two-dimensional velocity encoded phase contrast MRI during gated, submaximal isometric contractions, movements of triceps surae muscles (TSM) were tracked both in superior-inferior (SI) and ant...

The in vivo strain properties of human skeletal muscle-tendon complexes are poorly understood, particularly following chronic periods of reduced load bearing. We studied eight healthy volunteers who underwent 4 wk of unilateral lower limb suspension (ULLS) to induce chronic unloading. Before and after the ULLS, maximum isometric ankle plantar flexi...

The general objective of this study was to investigate biomechanical characteristics of bowling swing using three-dimensional cinematography. This study focused specifically on movements of the upper body segments during a bowling swing. Eight elite female bowling players participated in this study. Subjects performed bowling swing and their perfor...

The purpose of this study was to investigate steady-state force depression following active muscle shortening in human tibialis anterior muscle during voluntary contractions. Subjects (n = 7; age years; 7 males) performed isometric reference contractions and isometric-shortening-isometric contractions, using maximal voluntary effort. Force depressi...

PURPOSE Atrophy, from a variety of clinical conditions such as prolonged bed rest, micro-gravity or limb immobilization, can have profound effects on the architectural, functional/elastic properties of the musclo-skeletal components of the involved limb. This study investigated these effects of chronic unloading on the human soleus in-vivo using ve...

The force-length relationship is a basic property of skeletal muscle. Knowledge of this relationship is necessary for most analyses of human movement, and in simulation models predicting movement control strategies. Studies on animal muscles have shown that force-length relationships for sub-maximal contractions are not related through a simple sca...

The purpose of this study was to investigate steady-state force depression following active muscle shortening in human adductor pollicis during voluntary and electrically induced contractions. Subjects (n = 12; age 28 +/- 5 years; 7 males and 5 females) performed isometric reference contractions and isometric-shortening-isometric contractions, usin...

For electrically stimulated muscles, it has been observed that maximal muscle force during and after stretch is substantially greater than the corresponding isometric force. However, this observation has not been made for human voluntary contractions. We investigated the effects of active muscle stretch on muscle force production for in vivo human...

Muscle inhibition (MI) in human knee extensors increases with increasing maximal voluntary force as a function of knee angle. It was speculated that this angle-dependent MI was modulated by force-dependent feedback, likely Golgi tendon organ pathways. Such angle-dependent MI is of clinical and theoretical importance. The purpose of this study was t...

Muscle shortening and stretch are associated with force depression and force enhancement, respectively. Previously, we have investigated the effect of combined dynamic contractions (i.e. a single shortening-stretch and stretch-shortening cycle) on force production (Herzog and Leonard, 2000). In order to investigate the relationship between force de...

The purpose of this study was to determine the influence of speed and distance of muscle shortening on the amount of force depression for voluntary contractions. Two experimental tests were performed. In the first test, subjects performed isometric knee extensor contractions following muscle shortening produced by isokinetic knee extensions over th...

The purpose of this study was to investigate whether the isometric muscle force, redeveloped following maximal-effort voluntary shortening contractions in human skeletal muscle, is smaller than the purely isometric muscle force at the corresponding length. Isometric knee extensor moments, surface electromyographic (EMG) signals of quadriceps femori...

INTRODUCTION: The movement of plantar fascia under the foot has been characterized by foot arch strain in vitro (Kogler, Solomonidis, & Paul, 1995). The characteristics of the foot arch strain under the static and dynamic conditions in excessive pronators are not well known. Therefore, the purpose of this study is to investigate the foot arch strai...

INTRODUCTION The maximal isometric muscle force produced following shortening contractions is smaller than the corresponding force during purely isometric contractions (Abbott & Aubert, 1952). This phenomenon, referred to as force depression following shortening, has been observed in single fibres (Edman, et al., 1993; Sugi and Tsuchiya, 1988), who...

"June, 1999." Thesis (M.Sc)--University of Calgary, 1999. Includes bibliographical references (leaves 50-53). Microfiche.