Limb Joint Angles Research Articles

퍼팅 시 프로와 아마추어, 초보 골퍼사이의 운동학적 변인과 그립 악력 비교

The purpose of this study was to compare the differences in kinematic variables and grip forces among professionals(PG), amateurs(AG), and novice group(NG) during golf putting. The participants consisted of 3 groups based on their playing ability: 8 professional golfers (handicap<5), 8 amateurs (handicap<18) and 8 novice. Each subject attempted 2.1m putts from the hole. 3D motion analysis system(Motion analysis Corp., USA) with 6 high speed cameras and grip force measurement system(Kim et al., 2007) were used to acquired kinematic and force data, respectively. To compare differences among groups, joint angles of upper limbs, trajectory and smoothness by jerk cost function(JC) of putter head and grip forces were used in this study. Results showed that there were significant differences among groups in most of variables such as joint angles, trajectory & smoothness of putter head, and distribution of grip force in both hands. In brief, we confirmed that putting stroke in PG was more accurate and smooth than that in other groups, especially NG, due to their well-controlled upper limbs and keeping grip forces constant in both hands. It can be concluded that due to skilled levels, fundamental differences of putting movement could be identified and these differences might be helpful for improving one's putting skills.

Experimental knee pain impairs postural stability during quiet stance but not after perturbations

The objective of this study was to examine the effect of experimental knee-related pain on postural control. Twelve healthy subjects stood as quietly as possible on a movable force platform (that measured the centre of pressure and provided fast perturbations) before, during, and after experimental knee-related pain. Lower limb electromyographic (EMG) activity and joint angles were measured. Experimental pain was induced by injecting hypertonic saline into the infrapatellar fat pad (unilateral and bilateral) and isotonic saline was used for control sessions. Compared with the baseline and control sessions, unilateral and bilateral knee-related pain during quiet standing evoked (1) an increased sway displacement in the anterior-posterior direction (P < 0.05), (2) larger knee flexion (P < 0.05), and (3) larger EMG changes. Bilateral pain also induced (1) larger medial-lateral sway displacement and speed (P < 0.05) and (2) larger left hip flexion (P < 0.05). During forward perturbations, subjects leaned forward during both painful conditions when compared with baseline (P < 0.05). The additional impairment by bilateral pain suggests that the non-painful limb in unilateral pain conditions compensates for the impaired postural control. These results show that knee-related pain impairs postural stability during quiet standing, indicating the vulnerability of patients with knee pain to falls. This measure could potentially help clinicians who seek to assess how pain responses may contribute to patient's postural control and stability during quiet standing.

Ambulant adults with spastic cerebral palsy: The validity of lower limb joint angle measurements from sagittal video recordings

BackgroundIn the development of a clinical program for ambulant adults with cerebral palsy (CP), we investigated the validity of joint angles measured from sagittal video recordings and explored if movements in the transversal plane identified with three-dimensional gait analysis (3DGA) affected the validity of sagittal video joint angle measurements. MethodsTen observers, and 10 persons with spastic CP (19–63 years), Gross Motor Function Classification System I–II, participated in the study. Concurrent criterion validity between video joint angle measurements and 3DGA was assessed by Bland–Altman plots with mean differences and 95% limits of agreement (LoA). Pearson's correlation coefficients (r) and scatter plots were used supplementary. Transversal kinematics ≥2 SD from our reference band were defined as increased movement in the transversal plane. ResultsThe overall mean differences in degrees between joint angles measured by 3DGA and video recordings (3°, 5° and −7° for the hip, knee and ankle respectively) and corresponding LoA (18°, 10° and 15° for the hip, knee and ankle, respectively) demonstrated substantial discrepancies between the two methods. The correlations ranged from low (r=0.39) to moderate (r=0.68). Discrepancy between the two measurements was seen both among persons with and without the presence of deviating transversal kinematics. ConclusionQuantifying lower limb joint angles from sagittal video recordings in ambulant adults with spastic CP demonstrated low validity, and should be conducted with caution. This gives implications for selecting evaluation method of gait.

Kinematics of obstacle clearance in the rat

Although the rat has become the favourite animal model in preclinical research on locomotion, studies designed to assess the strategy used by rats to avoid obstacle are lacking. Using an optoelectronic 3D motion analysis system, we therefore, compared the step pattern, timing and length variables of locomotor cycles, trajectories and joint angles of limbs when rats step between and over obstacles (3 cm-high) fixed on a treadmill belt (25 cm/s). Motion in all four limbs of adult animals with an initial age of 11 weeks was serially recorded for a period of 10 weeks. The results showed that obstacle clearance is associated with the reorganization of the basic step pattern resulting in increased stride length of all limbs, increased duration of the swing phase of the hindlimbs only, and the appearance of two quadrupedal stance phases. They also revealed that the elevation of limbs above the obstacle not only involves flexion but also displacement of the corresponding girdles. Remarkably, the trajectory of the trailing forelimb to get over the obstacle is almost a mirror image of the trajectory of the leading forelimb. Lastly, all of the parameters measured remained stable over the observation period during which body weight gain reached 100 g (one third of the initial body weight). In conclusion, our study may provide a basis for future studies aimed at understanding the neural pathways involved in pathologies associated with deficit/recovery of challenged locomotion in rats.

Experimental Muscle Pain Challenges the Postural Stability During Quiet Stance and Unexpected Posture Perturbation

Musculoskeletal pain impairs postural control and stability. Nine subjects stood as quietly as possible on a moveable force platform before, during, and after experimental pain in the right leg muscles. A moveable force platform was used to measure the center of pressure and provided unexpected perturbations. Lower limb muscle activity, joint angles, and foot pressure distributions were measured. Hypertonic saline was used to induce pain in the vastus lateralis, vastus medialis, or biceps femoris muscle of the right leg. Compared to baseline and control sessions, pain in the knee extensor muscles during quiet standing evoked: 1) larger sway area, greater medial-lateral center of pressure displacement and higher speed ( P < .05); 2) increased sway displacement in the anterior-posterior direction ( P < .05); and 3) increased electromyography (EMG) activity for left tibialis anterior and left erector spinae muscles ( P < .05). Pain provoked longer time to return to an equilibrium posture after forward EMG activity for, and pain in vastus medialis muscle decreased the time for the maximum hip flexion during this perturbation ( P < .05). These results show that muscle pain impairs postural stability during quiet standing and after unexpected perturbation, which suggest that people suffering from leg muscle pain are more vulnerable to falls. Perspective This article presents the acute responses to leg muscle pain on the postural control. This measure could potentially help clinicians who seek to assess how pain responses may contribute to patient’s postural control and stability during quiet standing and after recovering from unexpected perturbations.

Observation and physical practice: Coding of simple motor sequences

An experiment was conducted to determine the coordinate system used in the development of movement codes during observation and utilized on later physical practice performance of a simple spatial-temporal movement sequence. The task was to reproduce a 1.3-s spatial-temporal pattern of elbow flexions and extensions. An intermanual transfer paradigm with a retention test and two transfer tests was used: a mirror transfer test where the same pattern of muscle activation and limb joint angles was required and a nonmirror transfer test where the visual-spatial pattern of the sequence was reinstated on the transfer test. The results indicated a strong advantage for participants in the physical practice condition when transferred to the mirror condition in which the motor coordinates (e.g., pattern of muscle activation and joint angles) were reinstated relative to transfer performance when the visual-spatial coordinates were reinstated (visual and spatial location of the target waveform). The observation group, however, demonstrated an advantage when the visual-spatial coordinates were reinstated. These results demonstrate that codes based in motor coordinates can be developed relatively quickly for simple rapid movement sequences when participants are provided physical practice, but observational practice limits the system to the development of codes based in visual-spatial coordinates. Performances of control participants, who were not permitted to practise or observe the task, were quite poor on all tests.

Biomechanical Characteristics of the Modified Downward Facing Dog Yoga Pose in Healthy Older Adults

Increasingly, yoga is being promoted as a safe and effective exercise program for older adults. The Downward Facing Dog (DFD) is one of the most common yoga poses, classically practiced with the hands placed on the floor. However, for older practitioners, the pose is often modified (mDFD) by having the hands placed on a wall or the back of a chair in order to make it more accessible, and potentially safer; this study focused on the wall method. In view of the absence of published data on the biomechanical profile of the mDFD, it is important to characterize these variables to help determine the physical demands of this yoga pose. This will lead to the development of balanced, safe and effective yoga programs for older adults. PURPOSE: To determine the kinematic and kinetic characteristics of the mDFD pose in healthy older adults. METHODS: 24 subjects (70.8 yrs ±4.2) performed the mDFD under a qualified yoga instructor's guidance. Sagittal plane kinetic and kinematic data were obtained in the position of maximal forward bending, using instrumented force platforms and an 11-camera motion capture system (60 Hz). Net joint moments were derived through standard inverse dynamic calculations. Flexion angles and flexor moments are reported as positive. RESULTS: In the sagittal plane, mean dominant limb joint angles were: ankle= 12.6 ±6.4°, knee= 26.2 ±13.5°, hip= 83.1 ±17.6°, shoulder= 118.8 ±13.6°, elbow= 48.8 ±15.6°, and wrist= -15.5 ±12.3°. The angle of trunk relative to pelvis was -9.0 ±11.3°, and head relative to trunk was 17.4 ±12.6°. Mean internal moments of the dominant leg in the sagittal plane were: ankle= -0.32 ±0.13N.m/kg (plantar-flexor), knee= 0.02 ±0.19 N.m/kg, and hip= -0.48 ±0.20 N.m/kg. The moment at the trunk was -43.90 ±17.24 N.m/kg. CONCLUSION: The largest joint excursion occurs at the shoulder. This is an important consideration for older adults with reduced shoulder range of motion. The biomechanical demands of the mDFD were primarily on the trunk extensors, hip extensors, knee flexors and ankle plantar-flexors. The plantar-flexor and extensor moments at the ankle and hip are the major contributors to the support moment. These data may be used to inform selection and modification of the mDFD pose to suit older adults with different musculoskeletal constraints and pathologies. Supported by NIH Grant ROI -AT004869-01

대퇴신경 손상 환아의 보행분석 : 사례연구

The femoral nerve innervates the quadriceps muscles and its dermatome supplies anteromedial thigh and medial foot. Paralysis of the quadriceps muscles due to the injury of the femoral nerve results in disability of the knee joint extension and loss of sensory of the thigh. A child could walk independently even though he had injured his femoral nerve severely due to the penetrating wound in the medial thigh. We measured and analyzed his gait performance in order to find the mechanisms that enabled him to walk independently. The child was eleven-year-old boy and he could not extend his knee voluntarily at all during a month after the injury. His gait analysis was performed five times (GA1~GA5) for sixteen months. His temporal-spatial parameters were not significantly different after the GA2 or GA3 test, and significant asymmetry was not observed except the single support time in GA1 results. The Lower limb joint angles in affected side had large differences in GA1 compared with the normal normative patterns. There were little knee joint flexion and extension motion during the stance phase in GA1 The maximum ankle plantar/dorsi flexion angles and the maximum knee extension angles were different from the normal values in the sound side. Asymmetries of the joint angles were analyzed by using the peak values. Significant asymmetries were found in GA1with seven parameters (ankle: peak planter flexion angle in stance phase, range of motion; ROM, knee: peak flexion angles during both stance and swing phase, ROM, hip: peak extension angle, ROM) while only two parameters (maximum hip extension angle and ROM of hip joint) had significant differences in GA5. The mid-stance valleys were not observed in both right and left sides of vertical ground reaction force (GRF) in the GA1, GA2. The loading response peak was far larger than the terminal stance peak of vertical ground reaction curve in the affected side of the GA3, GA4, GA5. The measured joint moment curves of the GA1, GA2, GA3 had large deviations and all of kinetic results had differences with the normal patterns. EMG signals described an absence of the rectus femoris muscle activity in the GA1 and GA2 (affected side). The EMG signals were detected in the GA3 and GA4 but their patterns were not normal yet, then their normal patterns were detected in the GA5. Through these following gait analysis of a child who had selective injuries on the knee extensor muscles, we could verify the actual functions of the knee extensor muscles during gait, and we also could observe his recovery and asymmetry with quantitative data during his rehabilitation.

A novel robotic system for quantifying arm kinematics and kinetics: Description and evaluation in therapist-assisted passive arm movements post-stroke

We developed a system for quantitatively measuring arm movement. Our approach provides a method to simultaneously capture upper limb kinetic and kinematic data during assisted passive arm movements. Data are analysed with respect to Cartesian and upper limb coordinate systems to obtain upper limb joint angles and torques.We undertook an evaluation of the system in participants with stroke to show the feasibility of this approach. During rehabilitation after stroke, one aspect of treatment includes the physiotherapist applying assistive forces to move the impaired arm of the patient who remains passive. There is a dearth of published data on the relationship between upper limb kinematics and the underlying forces (kinetics) in this mode of physiotherapy treatment. Such quantitative data are crucial in facilitating research into therapy practice, for example by measuring variation in practice and determining dosage. An experienced therapist prescribed passive movements tailored to the needs of 16 participants with stroke (41–81 years) with a range of anthropometric sizes and motor impairments. Our novel measurement tool recorded kinematic and kinetic data at 100Hz for 6–11 movements per participant. The kinetic data show that the majority of movements fall within upper limits of 36.7N in shoulder elevation, 22.4N in shoulder protraction, 4.6Nm in shoulder abduction, 12.8Nm in shoulder flexion, 2.4Nm in shoulder rotation and 5.5Nm in elbow flexion. These data show the potential of this system to better understand arm movement, in particular to objectively evaluate physical therapy treatments and support development of robotic devices to facilitate upper limb rehabilitation.

Análise do alinhamento dos membros inferiores em crianças com excesso de peso. DOI: 10.5007/1980-0037.2011v13n2p124

Overweight and obesity have reached epidemic proportions, especially among school- children, and have become a global health problem. Many adaptations in postural organization are observed in overweight and obese children, which have serious consequences. Posture assessment contributes to the understanding of these changes. The aim of this study was to assess changes in lower limb posture of overweight and obese children using a specific method. Twenty-two subjects, 9 girls and 13 boys, aged 5-9 years participated in the study. Posture was assessed by photogrammetry using the SAPo software. The lower limb joint angles and plantar projection of the center of gravity were analyzed. Nonparametric and descriptive statistics were used, in addition to the Kruskal-Wallis and Mann-Whitney tests (p < 0.05) for comparison between genders. Both groups showed anterior pelvic tilt and slight rotation (to the right in girls and to the left in boys), hyperextension, and valgus knees and ankles. The center of gravity presented 26.95% anteriorization. In conclusion, posture assessment in this population was consistent with literature findings and the method used permitted the quantification of data for future comparisons.

Gait kinematic analysis in patients with a mild form of central cord syndrome

BackgroundCentral cord syndrome (CCS) is considered the most common incomplete spinal cord injury (SCI). Independent ambulation was achieved in 87-97% in young patients with CCS but no gait analysis studies have been reported before in such pathology. The aim of this study was to analyze the gait characteristics of subjects with CCS and to compare the findings with a healthy age, sex and anthropomorphically matched control group (CG), walking both at a self-selected speed and at the same speed.MethodsTwelve CCS patients and a CG of twenty subjects were analyzed. Kinematic data were obtained using a three-dimensional motion analysis system with two scanner units. The CG were asked to walk at two different speeds, at a self-selected speed and at a slower one, similar to the mean gait speed previously registered in the CCS patient group. Temporal, spatial variables and kinematic variables (maximum and minimum lower limb joint angles throughout the gait cycle in each plane, along with the gait cycle instants of occurrence and the joint range of motion - ROM) were compared between the two groups walking at similar speeds.ResultsThe kinematic parameters were compared when both groups walked at a similar speed, given that there was a significant difference in the self-selected speeds (p < 0.05). Hip abduction and knee flexion at initial contact, as well as minimal knee flexion at stance, were larger in the CCS group (p < 0.05). However, the range of knee and ankle motion in the sagittal plane was greater in the CG group (p < 0.05). The maximal ankle plantar-flexion values in stance phase and at toe off were larger in the CG (p < 0.05).ConclusionsThe gait pattern of CCS patients showed a decrease of knee and ankle sagittal ROM during level walking and an increase in hip abduction to increase base of support. The findings of this study help to improve the understanding how CCS affects gait changes in the lower limbs.

Trunk and Upper Limb Muscle Activation During Flat and Topspin Forehand Drives in Young Tennis Players

This study compared EMG activity of young tennis players' muscles during forehand drives in two groups, GD-those able to raise by more than 150% the vertical velocity of racket-face at impact from flat to topspin forehand drives, and GND, those not able to increase their vertical velocity to the same extent. Upper limb joint angles, racket-face velocities, and average EMGrms values, were studied. At similar joint angles, a fall in horizontal velocity and a rise in racket-face vertical velocity from flat to topspin forehand drives were observed. Shoulder muscle activity rose from flat to topspin forehand drives in GND, but not for drives in GD. Forearm muscle activity reduced from flat to topspin forehand drives in GD, but muscle activation was similar in GND. The results show that radial deviation increased racket-face vertical velocity more at impact from the flat to topspin forehand drives than shoulder abduction.

A Preliminary Test of Measurement of Joint Angles and Stride Length with Wireless Inertial Sensors for Wearable Gait Evaluation System

The purpose of this study is to develop wearable sensor system for gait evaluation using gyroscopes and accelerometers for application to rehabilitation, healthcare and so on. In this paper, simultaneous measurement of joint angles of lower limbs and stride length was tested with a prototype of wearable sensor system. The system measured the joint angles using the Kalman filter. Signals from the sensor attached on the foot were used in the stride length estimation detecting foot movement automatically. Joint angles of the lower limbs were measured with stable and reasonable accuracy compared to those values measured with optical motion measurement system with healthy subjects. It was expected that the stride length measurement with the wearable sensor system would be practical by realizing more stable measurement accuracy. Sensor attachment position was suggested not to affect significantly measurement of slow and normal speed movements in a test with the rigid body model. Joint angle patterns measured in 10 m walking with a healthy subject were similar to common patterns. High correlation between joint angles at some characteristic points and stride velocity were also found adequately. These results suggested that the wireless wearable inertial sensor system could detect characteristics of gait.

Low Limb Muscle Activation and Joint Angle in the Sagittal Plane During Drop Landing from Various Heights

[Purpose] The purpose of study was to verify various strategies for the prevention of injury in normal adults and to identify the risk factors of body injury by the biomechanical analysis of drop landing with selected external loads that are commonly experienced in daily living causing load on the foot, ankle and the entire body as well as an increase in impulse. [Subjects] The subjects of this study were 14 normal adults. [Methods] Measurements were carried out while the participants drop-landed from the heights of 20, 40 and 60 cm. [Results] The muscle activation of the individual muscles until the posture was stabilized significantly increased in the abductor hallucis, medial gastrocnemius, biceps femoris and vastus lateralis as the drop height increased. In addition, the movement of the individual joints to correct the posture while landing showed that the flexion angles of the hip joint and knee joint increased as the drop height increased. [Conclusion] We found that there was a great change in the muscle activation at the drop height of 40 cm and the flexion angle also changed at the drop height of 40 cm, indicating that 40 cm may be the drop height at which the strategy for the postural balance of humans changes while landing.

Kalman-Filtering-Based Joint Angle Measurement with Wireless Wearable Sensor System for Simplified Gait Analysis

The aim of this study is to realize a simplified gait analysis system using wearable sensors. In this paper, a joint angle measurement method using Kalman filter to correct gyroscope signals from accelerometer signals was examined in measurement of hip, knee and ankle joint angles with a wireless wearable sensor system, in which the sensors were attached on the body without exact positioning. The lower limb joint angles of three healthy subjects were measured during gait with the developed sensor system and a 3D motion measurement system in order to evaluate the measurement accuracy. Then, 10m walking measurement was performed under different walking speeds with a healthy subject in order to find the usefulness of the system as a simplified gait analysis system. The joint angles were measured with reasonable accuracy, and the system showed joint angle changes that were similar to those shown in a previous report as walking speed changed. It would be necessary to examine the influence of sensor attachment position and method for more stable measurement, and also to study other parameters for gait evaluation.

Upper limb and trunk kinematics in tree planters during three load carriage conditions

Tree planters use various strategies to unload the seedlings from their bags. This study examines differences in upper limb and trunk joint angles during three load carriage conditions: (1) load evenly distributed to the right and left sides of the body – evenly loaded (2) load entirely on the right side – right loaded and (3) load entirely on the left side – left loaded. Data were collected in the field in Northern Ontario. Inertial motion sensors were placed on the right hand, right and left forearms and upper arms, sacrum, and T1 vertebrae. Using relative sensor orientation, joint angles were determined for the right wrist, right and left elbow and the trunk for the three load carriage conditions during normal planting tasks. The main findings were: 1) In the left loaded condition, the right wrist was less extended, the right elbow was more flexed, the trunk experienced less right-rotation, and the right and left forearms were less pronated than in either the evenly loaded or right loaded conditions. 2) In both the left and right loaded conditions, the left forearm was less pronated, and the trunk was less flexed than in the evenly loaded condition. Results suggest that asymmetrical tree load carriage results in more neutral postures than symmetrical tree load carriage.

Computer-Aided Working Space Design for Driller Control Cab

The working space affected workers’ security, health, comfort and working efficiency, which was an important research field of the human-machine system. According to the actual working situation of Chinese driller, the computer simulation of working space nearby driller was established. The lower limb joint angle changed in a comfortable range, which determined the area of H point, and then the regulated quantity of the driller’s chair was calculated by the computer. The working space satisfied both the short driller and the tall driller was obtained by the regulated quantity of chair, which would be taken as the restriction to carry on the human-machine interface design of driller console. In this way, the ergonomics factor was considered in the initial stage of design, and the efficiency of design was improved greatly. Finally, the CATIA human body posture analysis module was used to examine this design proposal, which proved that this method was feasible and effective.

Limb kinematics during locomotion in the two-toed sloth ( Choloepus didactylus, Xenarthra) and its implications for the evolution of the sloth locomotor apparatus

In order to gain insight into the function of the extant sloth locomotion and its evolution, we conducted a detailed videoradiographic analysis of two-toed sloth locomotion (Xenarthra: Choloepus didactylus). Both unrestrained as well as steady-state locomotion was analyzed. Spatio-temporal gait parameters, data on interlimb coordination, and limb kinematics are reported. Two-toed sloths displayed great variability in spatio-temporal gait parameters over the observed range of speeds. They increase speed by decreasing the durations of contact and swing phases, as well as by increasing step length. Gait utilization also varies with no strict gait sequence or interlimb timing evident in slow movements, but a tendency to employ diagonal sequence, diagonal couplet gaits in fast movements. In contrast, limb kinematics were highly conserved with respect to ‘normal’ pronograde locomotion. Limb element and joint angles at touch down and lift off, element and joint excursions, and contribution to body progression of individual elements are similar to those reported for non-cursorial mammals of small to medium size. Hands and feet are specialized to maintain firm connection to supports, and do not contribute to step length or progression. In so doing, the tarsometatarsus lost its role as an individual propulsive element during the evolution of suspensory locomotion. Conservative kinematic behavior of the remaining limb elements does not preclude that muscle recruitment and neuromuscular control for limb pro- and retraction are also conserved. The observed kinematic patterns of two-toed sloths improve our understanding of the convergent evolution of quadrupedal suspensory posture and locomotion in the two extant sloth lineages.

Welcome to a New Journal

This project examines kinematic gait parameters as forensic predictors of the influence associated with individuals carrying concealed weighted packs up to 20% of their body weight. An initial inverse dynamics approach combined with computational algebra provided lower limb joint angles during the stance phase of gait as measured from 12 human subjects during normal walking. The following paper describes the additional biomechanical analysis of the joint angle data to produce kinetic and kinematic parameters further characterizing human motion. Results include the rotational velocities and accelerations of the hip, knee, and ankle as well as inertial moments and kinetic energies produced at these joints. The reported findings indicate a non-statistically significant influence of concealed pack load, body mass index, and gender on joint kinetics (p>0.05). Ratios of loaded to unloaded kinematics, however, identified some statistical influence on gait (p<0.05). On-going studies are examining an additional subject cohort with greater pack loads in an effort to identify alterations in gait signatures as a counter-terrorism approach.

여성노인의 태권에어로빅스 12주 훈련 후 몸통지르기 동작시 하지관절의 생체역학적 변화

The purpose of this study was to investigate the biomechanical alterations in the punching motion of 10 elderly women after 12 weeks of taekwonaerobics training. Seven infrared cameras(Qualisys MCU-240) and 2 force platforms(Kistler-9286AA) were used to acquire raw data. The results were as follows. First, the minimum joint angles of the lower limbs had a statistically significant difference between both the dorsiflexion/plantar flexion(1eft, $p