BACKGROUND: There is currently a paucity of devices available for continuous, long-term monitoring of human joint motion. Non-invasive, inexpensive devices capable of recording human activity and joint motion have many applications for medical research. Such a device could be used to quantify range of motion outside the gait laboratory. The ...

BACKGROUND: Active inversion and eversion ankle range of motion (ROM) is widely used to evaluate treatment effect, however the error associated with the available measurement protocols is unknown. This study aimed to establish the reliability of goniometry as used in clinical practice. METHODS: 30 subjects (60 ankles) with a wide ...

BACKGROUND: The pendulum test of Wartenberg is a technique commonly used to measure passive knee motion with the aim to assess spasticity. We used this test to evaluate changes of the knee angular displacement, passive stiffness and viscosity in rheumatoid arthritis patients. Stiffness and viscosity represent passive resistances to joint ...

It is difficult to identify objective parameters for assessing the joint function when evaluating the outcome of orthopaedic procedures, especially endoprosthetic replacement. Spatial and temporal parameters of gait have clinical relevance in the assessment of motor pathologies, particularly in orthopaedics. However, the influence of gait speed on these biomechanical parameters ...

Starting from studies which revealed that positive feedback is found in the control system for walking in arthropods, we have constructed a new positive feedback driven joint that can be used for solving compliant motion tasks. We propose two different joint constructions each of which shows passive compliance. Based on ...

BACKGROUND: The midtarsal joint, consisting of the talo-navicular and the calcaneocuboid joints, is presumed to be responsible for the foot being both flexible and rigid during different parts of the stance phase of gait. However, this mechanism has never been well quantified. This study explores the midtarsal joint locking mechanism ...

BACKGROUND: Development of reconstructive operative procedures to restore normal ankle kinematics after injury requires an understanding of the biomechanics of the ankle during gait. The contribution of the peri-ankle ligaments to ankle motion control is not yet well understood. Knowledge of the tensile engagement of the peri-ankle ligaments during stance ...

OBJECTIVE: To investigate the effect of repeated feedback-controlled and programmed "intelligent" stretching of the ankle plantar- and dorsiflexors to treat subjects with ankle spasticity and/or contracture in stroke. DESIGN: Noncontrolled trial. SETTING: Institutional research center. PARTICIPANTS: Subjects with spasticity and/or contracture after stroke. INTERVENTIONS: Stretching of the plantar- and dorsiflexors ...

BACKGROUND: Motion at the midfoot joints can contribute significantly to overall foot motion during gait. However, there is little information regarding the kinematic coupling relationship at the midfoot. The purpose of the present study was to determine whether the coupling relationship at the midfoot and subtalar joints was affected when ...

The mechanical effects of genu valgum and varum deformities on the subtalar joint were investigated. First, a theoretical model of the forces within the foot and lower extremity during relaxed bipedal stance was developed predicting the rotational effect on the subtalar joint due to genu valgum and varum deformities. Second, ...

During ballistic locomotion and landing activities, the lower extremity joints must function synchronously to dissipate the impact. The coupling of subtalar motion to tibial and knee rotation has been hypothesized to depend on the dynamic requirements of the task. This study was undertaken to look for differences in the coupling ...

This article reviews the existing range-of-motion measurement literature related to ankle dorsiflexion and plantarflexion to determine whether the reliability of ankle range-of-motion measurements can be defined, how the characteristics of the study population or clinician affect reliability, and the level of responsiveness for these measures. A MEDLINE search was performed ...

In the present paper we introduce a movement planning model that is capable of predicting object manipulation movements in three dimensions. A basic assumption of this model is that the joint kinematics of the movement are optimized, which implies that joint rotations are synchronous. Synchronous joint rotations can be considered ...

BACKGROUND: The results found in the literature regarding functional ankle joint stabilization are controversial possibly because of the testing methods used. METHODS: The responses of 22 subjects to unexpected and expected sudden inversions of the foot were compared for all subjects together, as well as grouped by their self-perceived stability. ...

A power law describes the relationship between the geometric properties of a trajectory (radius of curvature) and movement kinematics (tangential velocity) in curved drawing movements. Although the power law is a general law of motion, there are conditions under which it degrades. In particular, the power law may be less ...

In situ force in the anterior cruciate ligament (ACL) has been quantified both in vitro in response to relatively simple loads by means of robotic technology, as well as in vivo in response to more complex loads by means of force transducers and computational models. However, a methodology has been ...

OBJECTIVE: To quantify angular excursions; net joint moments; and powers across the stifle, tarsal, and metatarsophalangeal (MTP) joints in Labrador Retrievers and Greyhounds and investigate differences in joint mechanics between these 2 breeds of dogs. ANIMALS: 12 clinically normal dogs (6 Greyhounds and 6 Labrador Retrievers) with no history of ...

The purpose of this study is to introduce a new technique for recording the kinematics of the temporomandibular joint and incisors, using an electromagnetic tracking device and custom dental appliance. Five normal subjects took part in this kinematic study (4 females, 1 male, mean age of 34.8 years). Subjects' mandibular ...

This study quantified the systematic effects on wrist joint mechanics of changes in amplitude of displacement ranging from within the region of short-range stiffness (0.2% of resting muscle length) up to 3% of resting muscle length. The joint mechanics were modelled using a second-order system from which estimates of joint ...

The purpose of this study was to evaluate the kinematic changes that occur about the foot and ankle during gait in patients with degenerative joint disease (DJD). By comparing a normal adult population with what was found in the DJD population we determined how the motion of theses groups differed, ...

The purpose of this case series was to quantify the effectiveness of different compensatory strategies used by individuals with muscle weakness to produce knee extension during the stance phase gait. Subjects were three males with less than anti-gravity strength in the quadriceps femoris and a variable pattern of weakness elsewhere ...

BACKGROUND: Surgical correction of hallux valgus deformities often results in decreased first metatarsophalangeal joint (MTPJ) range of motion. Loss of motion has been shown to affect patient satisfaction. The purpose of this study was to evaluate the immediate change in MTPJ range of motion that occurs after a distal soft-tissue ...

This paper derives a simple mathematical model relating changes in the orientations of the two Cartesian coordinate systems involved in recording knee movement and the varus-valgus and the internal-external rotation angles for describing the knee's motion. Rotation matrices are given for changing the orientations of the two Cartesian coordinate systems ...

PURPOSE: Individuals with knee osteoarthritis (OA) experience pain, frontal plane joint laxity and instability. Co-contraction can control laxity and instability but may place constraints on the variability of the knee's motion during gait. Slight variation among gait cycles is normal, but reduced variability of joint motions could be detrimental. The ...

Fourteen patients, at a mean age of 9.1 years (range 4.1-16.6 years), who had spastic diplegic cerebral palsy were evaluated before and after tendo Achilles lengthening (TAL). Follow-up (by gait analysis) after TAL ranged from 8 to 30 months. A Vicon motion analysis system with six CCD cameras and two ...

Bioemchanics of the entire knee joint including tibiofemoral and patellofemoral joints were investigated at different flexion angles (0 degrees to 90 degrees ) and quadriceps forces (3, 137, and 411 N). In particular, the effect of changes in location and magnitude of restraining force that counterbalances the isometric extensor moment ...

BACKGROUND: It has been suggested that the function of the first metatarsophalangeal joint may be related to the motion of the ankle joint complex. OBJECTIVE: This study explored the relationship between ankle joint complex and first metatarsophalangeal joint motion during gait in a group of 14 who demonstrated clinically limited ...

BACKGROUND: Joint stabilisation processes have been mainly studied comparing groups or joints with different stabilities and mainly focusing on one single parameter. The inherent limitations are discussed and a study, where kinematic, kinetic and electromyografic parameters gained from sudden tilt tests were measured, is presented. METHODS: The response of 24 ...

BACKGROUND: An experiment has recently been conducted to evaluate and compare the differences in tendon excursions between the flexor digitorum profundus and superficialis using three mobilization techniques. No previous studies deal with the total joint excursions with constant tendon length. The purpose of this study was to investigate the coordinated ...

Gait analysis has been used as an investigative tool for locomotion disorders since the early 20th century when it was done using time-lapsed photography. Since the advent of video and advances in strain gauge technology and fast data-handling devices coupled with computers, many of the movements and forces acting on ...

We analyzed the adaptability of human thumb and index finger movement kinematics and dynamics to variations of precision grip aperture and movement velocity. Six subjects performed precision grip opening and closing movements under different conditions of movement velocity and movement aperture (thumb and index finger tip-to-tip distance). Angular motion of ...

Impairments in control of multi-joint arm movements in Parkinson's Disease (PD) were investigated. The PD patients and age-matched elderly participants performed cyclical arm movements, tracking templates of a large circle and four differentially oriented ovals on a horizontal table. The wrist was immobilized and the movements were performed with shoulder ...

The purpose of this study was to investigate the movement speed characteristics of 2 intrinsically different limbs. Twenty subjects volunteered to participate (10 men and 10 women). Each subject performed 5 repetitions of concentric knee and elbow extension and flexion movements at 60 through 500 d.s(-1) on an isokinetic dynamometer. ...

PURPOSE: To further the understanding of double poling (DP) through biomechanical analysis of upper and lower body movements during DP in cross-country (XC) skiing at racing speed. METHODS: Eleven elite XC skiers performed DP at 85% of their maximal DP velocity (V85%) during roller skiing at 1 degrees inclination on ...

PURPOSE: The purpose of this investigation was to determine whether an isolated change in either quadriceps or hamstrings muscle force (quadriceps avoidance and hamstrings facilitation, respectively) is sufficient to stabilize the ACL-deficient (ACLd) knee during gait. METHODS: A three-dimensional model of the lower limb was used to calculate anterior tibial ...

Finger flexor tendon rehabilitation has come a long way, but further advances are possible. Ideally, a healing tendon should move, but under the minimum load necessary to achieve motion. It is possible to design suture repairs that minimize the friction between tendon and sheath while simultaneously maintaining adequate strength to ...

BACKGROUND: The practice of continuous, long-term monitoring of human joint motion is one that finds many applications, especially in the medical and rehabilitation fields. There is a lack of acceptable devices available to perform such measurements in the field in a reliable and non-intrusive way over a long period of ...

BACKGROUND: Based on the phenomenon of bone adaptation to mechanical stimuli (Wolff's law) this study investigates a previously unreported correlation between the maximum wrist joint reaction force and the volar tilt angle of the distal radius. METHODS: Free body analysis of the sagittal-plane forces acting on the supinated distal radius ...

When using optoelectronic stereophotogrammetry, skin deformation and displacement causes marker movement with respect to the underlying bone. This movement represents an artifact, which affects the estimation of the skeletal system kinematics, and is regarded as the most critical source of error in human movement analysis. A comprehensive review of the ...

OBJECTIVE: To compare the 3-dimensional (3D) orientation of the tibiotalar, tibiocalcaneal, and intertarsal joints in cadaveric specimens following structural weakening to predetermined ligaments in the peritalar region and medial ankle tendons under axial loads and simulated calcaneal valgus deformity. METHODS: Eight fresh-frozen, unembalmed human lower leg and foot specimens were ...

The dual Euler angles method has been proposed as an alternative approach to describe the general spatial human joint motion. In this study, the dual Euler angles method was applied to study the three-dimensional motion of the ankle complex. The methodology for obtaining dual Euler angles of the ankle complex ...

We studied the kinematics of the knee during weight-bearing active extension in 14 patients with medial osteoarthrosis (OA) and in 10 controls using dynamic radiostereometry. Between 50 degrees and 20 degrees of extension the OA knees showed decreased internal tibial rotation corresponding to less posterior displacement of the lateral femoral ...

BACKGROUND: Evans showed that lengthening the lateral column by inserting structural bone graft into the anterior calcaneus could correct abduction and valgus deformity in flatfoot. To better understand the mechanism of correction and the three-dimensional effect of this procedure a cadaver study was done. METHODS: Three cadaver flatfoot models were ...

The purpose of this study was to compare the knee extensor mechanics in persons with and without patella alta. Thirteen subjects with patella alta and 14 subjects with normal patellar position participated in the study. Sagittal and axial MR images of the knee were acquired at 0 degrees , 20 ...

The objective of this study is to validate previous descriptions of hindfoot kinematics using dual Euler angle methods in a passive cadaveric model. The dual Euler angle method was chosen so as to facilitate description of the translational and rotational movement occurring at both the ankle and subtalar joints. A ...

The aims of this study were to determine whether patellofemoral kinematics in the anteroposterior (AP), mediolateral (ML) and proximal-distal (PD) directions could be measured in real time with high repeatability using a three-dimensional magnetic tracking system, and to evaluate the symmetry between sides. Data was collected from both knees of ...

Range of motion after total knee arthroplasty is an important variable in determining clinical outcome. The goal of this study was to assess range of motion across five types of posterior-stabilized knee prostheses used sequentially in the same institution during 17 years. The hypothesis was that absolute flexion would improve ...

A three-dimensional (3D) biomechanical model was developed to determine upper extremity kinematics and kinetics of persons walking with forearm crutches. Six-component load cells and strain gauges were installed in the crutches to determine crutch forces. A six-camera VICON motion system was used to acquire coordinate data from 24 reflective markers ...

BACKGROUND: Quantifying the in vivo cartilage contact mechanics of the knee may improve our understanding of the mechanisms of joint degeneration and may therefore improve the surgical repair of the joint after injury. OBJECTIVE: To measure tibiofemoral articular cartilage contact kinematics during in vivo knee flexion. STUDY DESIGN: Descriptive laboratory ...

This article reports a systematic research effort aimed at establishing a normative database of thumb circumduction range of motion (ROM) and related kinematic characteristics in vivo while examining the effects of anthropometry, gender, and direction of rotation. Twenty-eight (14 men, 14 women) anthropometrically diverse participants performed maximum voluntary thumb circumductions ...