Video-based Motion Analysis Research Articles

Scapular Summit 2009, July 16, 2009, Lexington, Kentucky

This was the third research meeting focused on scapular function and dysfunction, following similar meetings in 2003 and 2006. The purpose of this meeting, hosted by the Shoulder Center of Kentucky, was to continue to examine the biomechanical and clinical factors thought to be associated with the role of the scapula in shoulder function and dysfunction. Since the last Summit, much more information has been created in this area, and it was thought that enough progress had been made that an organized overview of current knowledge could provide some consensus statements to guide further research and provide assessment and treatment guidelines. A call for abstracts was extended to researchers with proven interest and published research on the scapula. The meeting was organized around 3 primary categories of information: scapular kinematics and dysfunction, clinical evaluation of the scapula, and interventions. The last session of the meeting involved development of consensus statements for each category. This document represents the current state of knowledge concerning the aspects of scapular function and dysfunction discussed at the Summit. It is expected that, as more knowledge is developed, the gaps will be filled in and a clearer understanding of the roles of the scapula in shoulder function will emerge. This issue includes the consensus statements and abstracts from the Summit.

Manual stimulation of the orbicularis oculi muscle improves eyelid closure after facial nerve injury in adult rats

We have shown that manual stimulation of rat whisker-pad muscles following facial-facial-anastomosis (FFA) restores normal whisking by lowering the proportion of polyinnervated motor endplates. Here we examined whether manual stimulation of the orbicularis oculi muscle (OOM) after FFA would also improve outcome. Blink responses to standardized air puffs were analyzed using video-based motion analysis. Two months after FFA, blink capacity was impaired, as indicated by a largely increased minimum distance between the eyelids after air-puff stimulation compared with intact rats (2.7 +/- 0.4 vs. 0.2 +/- 0.01 mm). Manual stimulation reduced this deficit by a factor of two (1.3 +/- 0.5 mm). The functional improvement after manual stimulation was associated with a 2-fold decrease in the proportion of polyinnervated OOM endplates (21 +/- 10% vs. 42 +/- 10% without manual stimulation, 0% in intact rats). We conclude that manual stimulation is a noninvasive and simple procedure with immediate potential for clinical rehabilitation of eyelid closure following facial nerve injury.

Comprehensive Biomechanical Examination of Children with Initial Stages of Idiopathic Scoliosis

The paper presents the need for a complex assessment of statodynamic function of musculoskeletal system as a whole in patients with idiopathic scoliosis. Advantages and prospects for usage of such techniques for musculoskeletal biomechanics study as optical topography, stabilography, dynamic plantography, and video-based motion analysis are discussed.

Local stabilization of microtubule assembly improves recovery of facial nerve function after repair

Within a recent study on the recovery of vibrissae motor performance after facial nerve repair in blind (strain SD/RCS) and sighted (strain SD) rats, we found that, despite persisting myotopic disorganization in the facial nucleus, the blind animals fully restored vibrissal whisking. Searching for the morphological substrates of this improved recovery, we compared the amount of cytoskeletal proteins in the leading edge of elongating axons between both strains. Since our results showed an enhanced expression of neuronal class III β-tubulin in the blind rats, we wondered whether this was due to an increased synthesis or to a delayed turnover of microtubules. In the present report, we approached this question applying established pharmacological agents to the transected buccal branch of the facial nerve in sighted Wistar rats perturbing either microtubule assembly towards stabilization (enhanced polymerization with 10 μg/ml taxol) or towards increased synthesis (challenged by destabilization with 100 μg/ml nocodazole and 20 μg/ml vinblastine). Evaluation of the effect(s) 2 months later included estimation of (i) vibrissae motor performance by video-based motion analysis, (ii) the degree of collateral axonal branching by double retrograde neuronal labeling with crystals of Fluoro-Gold and DiI and (iii) the pattern of motor end-plate reinnervation (proportions of mono- and poly-reinnervated) in the largest extrinsic vibrissal muscle, the m. levator labii superioris. We found that only stabilization of microtubules with 10 μg/ml taxol reduced intramuscular axonal sprouting and polyinnervation of the motor end-plates, which was accompanied by improved restoration of function.

Case study evaluation of body weight-supported treadmill training for parkinsonian gait

Parkinsonian gait is characterized by kinetic and kinematic anomalies such as reduced push-off and reduced walking velocity. It is evident that any improvement to gait is likely to result in concomitant improvement in aspects of everyday life that require whole body ambulation. Consequently, the aim of this study was to quantify, biomechanically, the potential of body weight-supported treadmill training (BWSTT) in eliciting a shift toward a more normal pattern of gait for individuals with Parkinson's disease. A single-subject intervention-based research design was adopted. Kinetic, kinematic and spatiotemporal data were captured via the simultaneous use of a Kistler force platform and an automated video-based motion analysis system. The emphasis of the BWSTT intervention was to provide stimulus to the extensor load receptors of the lower extremities through the unloading and reloading of body weight, characterized through kinetic and kinematic profiles (Dietz, 1997). The findings of the study revealed significant enhancement—relative to ‘normal’ gait—of parkinsonian gait following BWSTT, which was reflected in observed normalization across measured spatiotemporal, kinematic, and kinetic parameters. As such, BWSTT may be a viable method of implementing sustained improvement to parkinsonian gait, although further large-scale research is needed.

Mechanical stimulation of paralyzed vibrissal muscles following facial nerve injury in adult rat promotes full recovery of whisking

Many patients suffer lifelong disabilities after peripheral nerve injury. Insufficient recovery has been attributed to excessive axonal branching, axonal regrowth to improper targets and polyneuronal reinnervation of motor endplates. We used the rat facial nerve transection/suture model to quantify the effects of mechanical stimulation on the paralyzed whisker musculature. "Manual" stimulation involved briskly stroking the whiskers by hand in a manner that specifically mimicked normal whisker movement. "Environmental" stimulation involved enhanced whisker use as rats encountered objects in an enriched environment. Manual and environmental stimulation were also combined. Video-based motion analysis of vibrissal motor performance showed that daily manual, but not environmental, stimulation for 2 months resulted in full recovery of whisking. Polyneuronal reinnervation of motor endplates was reduced but not misdirected axonal regrowth. Our findings indicate the potential of use-specific training to enhance appropriate functional outcome after peripheral nerve injury and may be useful in a clinical rehabilitation setting.

Carbohydrate mimics promote functional recovery after peripheral nerve repair

The outcome of peripheral nerve repair is often unsatisfactory, and efficient therapies are not available. We tested the therapeutic potential of functional mimics of the human natural killer cell glycan (3-sulfoglucuronyl beta1-3 galactoside) (HNK-1) epitope, a carbohydrate indicated to favor specificity of motor reinnervation in mice. We applied a linear HNK-1 mimic peptide, scrambled peptide, or vehicle substances in polyethylene cuffs used to reconstruct the severed femoral nerves of adult mice. We used video-based motion analysis and morphological and tracing techniques to monitor the outcome of nerve repair. After glycomimetic application, quadriceps muscle function recovered to 93% of normal within 3 months. Restoration of function was less complete (71-76%) in control groups. Better functional recovery was associated with larger motoneuron somata, better axonal myelination in the quadriceps nerve, and enhanced precision of target reinnervation. Lesion-induced death of motoneurons was reduced by 20 to 25%. The glycomimetic enhanced survival and neurite outgrowth of both mouse and human motoneurons in vitro by 30 to 75%. Application of a novel cyclic glycomimetic also enhanced functional recovery in vivo. The improved outcome of nerve repair after glycomimetic application may be attributed to neurotrophic effects. Our results hold promise for therapeutic use in humans.

The feasibility of a video-based motion analysis system in measuring the segmental movements between upper and lower cervical spine

The evaluation of the range of motion (ROM) and static posture in the cervical spine are important in physical examination. Despite offering dynamic assessment without radiation, the video-based motion analysis system has not yet been applied to measure the cervical segmental movements. The purposes of this study were to develop a neck model to differentiate the movements and posture between upper and lower cervical spine, and to examine the reliability of measuring cervical motion with surface markers and the aid of videofluoroscopy. Sixteen healthy adult subjects (eight males and eight females) participated in this study. Ten surface markers were used to estimate the discrepancies in cervical vertebral angles compared with corresponding bony landmarks throughout the ROM. The average intraclass correlation coefficients (ICCs) of the paired vertebral angles between surface markers and bony landmarks ranged from 0.844 to 0.975 and the mean absolute difference (MAD) averaged 2.96°. Our results indicate high consistency between surface markers and bony landmarks throughout the cervical movements. The mean upper (C0–C2) and lower (C2–C7) cervical joint angles in the neutral position were 18.59 ± 4.33° and 23.98 ± 6.15°, respectively. Furthermore, the reliability of the digitizing procedure within raters (ICC = 0.850–0.999; MAD = 0.58–2.42°) and between raters (ICC = 0.759–0.988; MAD = 0.59–2.66°) suggests that the neck motion analysis model is a feasible method for investigating static neck posture or dynamic motion between upper and lower cervical spine.

In Vitro Assessment of a Motion-Based Optimization Method for Locating the Talocrural and Subtalar Joint Axes

The locations of the joint axes of the ankle complex vary considerably between subjects, yet no noninvasive method with demonstrated accuracy exists for locating these axes. The moments of muscle and ground reaction forces about the joint axes are dependent on axis locations, making knowledge of these locations critical to accurate musculoskeletal modeling of the foot and ankle. The accuracy of a computational optimization method that fits a two-revolute model to measured motion was assessed using computer-generated data, a two-revolute mechanical linkage, and three lower-leg cadaver specimens. Motions were applied to cadaver specimens under axial load while bone-mounted markers attached to the tibia, talus, and calcaneus were tracked using a video-based motion analysis system. Estimates of the talocrural and subtalar axis locations were computed from motions of the calcaneus relative to the tibia using the optimization method. These axes were compared to mean helical axes computed directly from tibia, talus, and calcaneus motions. The optimization method performed well when the motions were computer-generated or measured in the mechanical linkage, with angular differences between optimization and mean helical axes ranging from 1 deg to 5 deg. In the cadaver specimens, however, these differences exceeded 20 deg. Optimization methods that locate the anatomical joint axes of the ankle complex by fitting two revolute joints to measured tibia-calcaneus motions may be limited because of problems arising from non-revolute behavior.

Reduced Hip Extension in the Elderly: Dynamic or Postural?

Lee LW, Zavarei K, Evans J, Lelas JJ, Riley PO, Kerrigan DC. Reduced hip extension in the elderly: dynamic or postural? Objective To test the hypothesis that reduced hip extension and increased anterior pelvic tilt in the elderly are dynamic gait phenomena that do not occur during normal standing posture. Design Experimental. Setting Gait laboratory. Participants Twenty-five older adult subjects (mean age ± standard deviation, 71±5y) and 25 young adult subjects (mean age, 26±5y). Intervention Subjects were observed during standing and walking at self-determined comfortable, slow, and fast walking speeds. Positions and kinematics of the pelvis and lower extremities were measured using a 3-dimensional video-based motion analysis system. Main Outcome Measures Peak hip extension and anterior pelvic tilt. Results There were no statistically significant differences between the older and young adult groups during standing with respect to either hip extension (3°±5° vs 1°±6°) or anterior pelvic tilt (11°±5° vs 10°±5°). On the other hand, at comfortable walking speeds, the older adult group had reduced peak hip extension (7°±6° vs 11°±6°, P<.05) and increased anterior pelvic tilt (15°±5° vs 11°±5°) compared with the young adult group. At fast walking speeds, peak hip extension was significantly reduced in the older adult group than in the young adult group (9°±6° vs 14°±6°, P<.05), but there was no significant difference at slow walking speeds (6°±6° vs 9°±5°). Conclusions Age-related changes in gait defined by reduced peak hip extension and increased pelvic tilt are dynamic rather than standing postural characteristics.

Time motion analysis of 2001 and 2002 super 12 rugby

The aim of this study was to quantify movements of Super 12 rugby players in competition because information on elite rugby players' movements is unavailable. Players were categorized into forwards [front (n = 16) and back row (n = 15)] and backs [inside (n = 9) and outside backs (n = 7)] and their movements analysed by video-based time motion analysis. Movements were classified as rest (standing, walking and jogging) and work (striding, sprinting, static exertion, jumping, lifting or tackling). The total time, number and duration of individual activities were assessed, with differences between groups evaluated using independent sample t-tests (unequal variances), while differences between halves were assessed with paired sample t-tests. Forwards had 7:47 min:s (95% confidence limits: 6:39 to 8:55 min:s, P<0.01) more time in static exertion than backs, but backs spent 0:52 (0:34 to 1:09, P = 0.01) min:s more time sprinting than forwards, and had a 0.7 (0.3 to 1.2, P = 0.01) s longer duration of each sprint. Forwards spent 7:31 (5:55 to 9:08) min:s more time in work activities (P = 0.01) and had 2.1 (1.3 to 2.8) s longer work durations (P<0.01) than backs. The results indicate frequent short duration (<4 s) work efforts followed by moderate duration (<20 s) rest for forwards, and extended (>100 s) rest duration for backs. High-intensity efforts involved static exertion for forwards (mean ± standard deviation frequency = 80 ± 17) and sprinting for backs (27 ± 9). In conclusion, after nearly a decade since becoming professional, elite rugby union is still characterized by highly intense, intermittent movement patterns and marked differences in the competition demands of forwards and backs.

Kinematic analysis of the gait of 10 labrador retrievers during treadmill locomotion

The trotting gait of 10 sound, adult labrador retrievers was analysed using kinematic gait analysis on a purpose-built treadmill using video-based motion analysis software. The maximal angular displacement, minimal angular...

Concepts and measurement of in vivo tibiofemoral kinematics

Recent studies of tibiofemoral kinematics in 6 degrees-of-freedom have given us a new perspective and demonstrated lateral compartmental roll-back centered on a medially oriented axis over a relatively stable medial compartment during functional arcs of sagittal knee motion. This translates into coupled internal tibial rotation with increasing knee flexion, which is altered by anterior cruciate ligament (ACL) injury. During terminal extension, the tensioned ACL provides an internal torque to the lateral femoral condyle with tightening of the lateral collateral ligament , culminating in the ‘screw-home mechanism’. Studies of tibiofemoral kinematics in the ACL-deficient knee have demonstrated posterior and medial shifts of the femur relative to the tibia reference point. In addition, the ACL-deficient knee also demonstrates different patterns of tibiofemoral kinematics during gait. Current ACL-reconstruction techniques will restore some functions of the ACL; however, some studies have suggested that anatomical ACL-reconstruction may better restore normal tibiofemoral kinematics. Although in vitro studies have contributed much to our knowledge of knee kinematics, increasingly accurate in vivo measurement techniques now offer new insight on rotational stability. The methodologies of in vivo kinematics include radiological techniques , video-based motion analysis, electromagnetic tracking devices, and ultrasound-based systems. As management of knee pathologies continue to evolve, development of reliable measures of rotational stability may be the next challenge in clinical and functional outcome assessment.

Effects of environmental and job-task factors on workers' gait characteristics on slippery surfaces

The objective of this study was to investigate the kinetic and kinematic aspects of slips associated with gait on a slippery surface under various environmental and job-task risk factors. Forty healthy industrial workers (age: 40.3 ± 14.9 years) participated in the study. Using a strain gauge type force platform and a video-based motion analysis system, kinetic and kinematic measurements of the subjects' foot movements were obtained. Of all gait trials, there were 1558 slips (60.9%). Slips were likely to occur when subjects were negotiating a turning path and an oily surface. Greater anterior-posterior center of pressure (CP) excursion and maximum required coefficient of friction (RCOF) were found for oily surfaces compared to dry surfaces. Subjects changed their gait patterns by shortening their stride length, slowing walking speed, and decreasing heel contact angle in the poorly lit and slippery environment. Significant correlations were found between slip occurrence and anterior-posterior CP excursion, mean RCOF, sliding distance and sliding velocity, but not the coefficient of friction (COF) of shoes. In addition to good housekeeping and proper selection of floor materials and safety shoes, slip and fall prevention should include proper workers' training in dealing with risk factors of slips and falls in the workplace.

Poster 152: Sagittal plane biomechanics and low back pain in transfemoral amputees.

Objectives: To document the extent of static lumbar lordosis and dynamic lumbar spine motion in the sagittal plane in transfemoral amputees and to determine whether excessive lumbar lordosis and excessive sagittal plane spine motion are related to low back pain (LBP) in transfemoral amputees. Design: A cross-sectional observational study. Setting: Motion analysis laboratory at a Veterans Affairs tertiary care facility. Participants: 6 ambulatory transfemoral amputees with a history of significant chronic LBP (CLBP) beginning after amputation and 3 ambulatory transfemoral amputees without history of CLBP since amputation. Interventions: Not applicable. Main Outcome Measures: L1-S1 Cobb angle from a lateral upright radiograph. Peak lumbar sagittal plane flexion and extension measured by a video-based motion analysis system. Results: The mean L1-S1 Cobb angle ± SD (range) were 62°±10° (44°–77°) for transfemoral amputees with LBP and 58°±3° (54°–61°) for transfemoral amputees without LBP. The mean maximum degrees of flexion (range) were 4.2°±5.9° (−8.0° to 13.7°) for transfemoral amputees with LBP and 3.0°±3.4° (−2.7° to 8.8°) for transfemoral amputees without LBP. The mean maximum degrees of extension (range) were −5.7°±6.4° (−21.0° to 2.3°) for transfemoral amputees with LBP and −5.9°±4.1° (−12.1° to 1.0°) for transfemoral amputees without LBP. Conclusions: The L1-S1 Cobb angle showed a significant relationship with LBP in transfemoral amputees ( P<.0313). The most extreme L1-S1 Cobb angles were seen in transfemoral amputees with LBP. There was no difference between the groups in either maximum lumbar flexion or extension ( P<0.3). From this data, static lumbar angles appear to be more related to LBP than the sagittal flexion and extension range of dynamic lumbar motion during gait; perhaps it is not the extremes of sagittal plane lumbar motion that place this population at risk. However, type II error cannot be excluded.

The correlation between severity of paraparesis and reduced density of resident antigen-presenting cells implicates an unknown role for the spinal perivascular macrophages in experimental autoimmune encephalomyelitis in rats

To study alterations in the morphology of spinal perivascular macrophages (SPM) during experimental allergic encephalomyelitis (EAE), we labelled SPM by intracerebroventricular (icv) injection of horseradish peroxidase (HRP). As earlier electron microscopical analysis had shown severely damaged SPM, we suspected that each inflammatory process is accompanied by the death of SPM. To prove this hypothesis, we compared the numerical density of resident SPM (icv labelled in red by Fluoro-Ruby) with that of monocytes/macrophages recruited to the perivascular space (icv labelled in green by Fluoro-Emerald). At the peak of paraparesis, the density of resident SPM was reduced by 33%. Since this reduction contrasted sharply with earlier data indicating a massive increase in the density of SPM during EAE, we checked our findings after general or selective suppression of the immune response to myelin autoantigens with the drugs dexamethasone and copaxone, respectively. Dexamethasone treatment commenced after evident paraparesis accelerated recovery, but did not influence SPM density. Immunisation with copaxone completely prevented the occurrence of EAE (monitored by video-based motion analysis of tail motility); the subsequent histological analysis revealed no reduction in SPM density. Based on this inverse correlation between the severity of EAE and the density of resident macrophages, we conclude that SPM plays an important role in the pathogenesis of EAE.

BIOMECHANICAL ANALYSIS OF CHAIR RISING IN THE PREGNANT WOMEN

There were so many changes in physiological and psychological aspects during pregnancy. Rising from a chair was an important functional activity of daily life. These changes impose postural demands and limit the performance of activities of daily living. The overall goals of this study were to quantify the effects of physiological change due to pregnancy on the performance of chair-rise and to analyze why some pregnant female have more difficulty with these tasks. Twenty-four pregnant women were included in this study to investigate the performance and possible related biomechanical factors of chair-rise. Body movements of these subjects were recorded using video-based motion analysis system. Three force plates were applied to obtain the ground reaction forces of foot, seat and armrest. Kinematics and kinetics data were analyzed to evaluate the angles and moments of the hip, knee and ankle joints. The result indicated that the maximum moment of the three joints occurred nearly in the beginning of extension phase. As the chair height increased, the maximum flexion angles decreased significantly at the hip, knee, and ankle joints. The chair height had great influence on knee joint and hip joint moments, but less on ankle joint. In the third stage (chair height: 65% KH), the maximum hip moment significantly decreased because of a remarkable increase in abdominal depth. In contrast to the hip moment, the maximum knee moment greatly increased. This result revealed the reason why pregnant female have more difficulty on the performance of chair-rise. Additionally, rising with the armrest for pregnant female would significantly decreased the maximum knee moment. This study suggested that pregnant female should select armrest or higher chair to decrease the joint loading during chair-rise.

An Example of Neural Plasticity Evoked by Putative Behavioral Demand and Early Use of Vibrissal Hairs after Facial Nerve Transection

Abnormally associated movements inevitably occur after surgical repair of the facial nerve. The reason for this postparalytic syndrome is poor navigation of regrowing axons. Despite the valuable functional advantage provided by the easily detected movement of vibrissae in rats, the major investigative tools for establishing the degree of misdirected reinnervation are still electrophysiologic recordings and retrograde tracing. In the present study we complemented data from pre- and postoperative retrograde labeling (FluoroGold, Fast Blue, DiI) of facial motoneurons with an evaluation of whisker movements. Using a video-based motion analysis system, we compared the recovery of vibrissae motor performance in visually normal and blind rats of the Sprague–Dawley strain. The analysis of whisker movement after facial nerve surgery revealed a striking discrepancy between morphologic and functional estimates. Whereas retrograde labeling displayed poor accuracy of target reinnervation and supernumerary axonal branching in both groups, the video-based motion analysis showed a perfect recovery of vibrissae movements in the blind rats. Attributing the complete recovery of whisker movement in the blind rats to an extraordinary plasticity of the facial motoneurons induced by putative behavioral demand and forced overuse, we conclude that the video-based analysis of whisker movement is a valuable tool for studying the progress in functional recovery.

Transplantation of olfactory mucosa minimizes axonal branching and promotes the recovery of vibrissae motor performance after facial nerve repair in rats.

The occurrence of abnormally associated movements is inevitable after facial nerve transection. The reason for this post-paralytic syndrome is poor guidance of regrowing axons, whereby a given muscle group is reinnervated by misrouted axonal branches. Olfactory ensheathing glia have been shown to reduce axonal sprouting and stimulate axonal regeneration after transplantation into the spinal cord. In the present study, we asked whether transplantation of olfactory mucosa (OM) would also reduce sprouting of a damaged peripheral pure motor nerve. The adult facial nerve was transected, and the effect of the OM placed at the lesion site was analyzed with regard to the accuracy of target reinnervation, axonal sprouting of motoneurons, and vibrissal motor performance. Accuracy of target reinnervation and axonal sprouting were studied using preoperative/postoperative labeling and triple retrograde labeling of facial motoneurons, respectively. The vibrissal motor performance was monitored using a video-based motion analysis. We show here that implantation of OM, compared with simple facial-facial anastomosis, (1) improved the protraction, amplitude, angular velocity, and acceleration of vibrissal movements up to 80% of the control values, (2) reduced the percentage of branching motoneurons from 76 to 39%, and (3) improved the accuracy of reinnervation from 22 to 49%. Moreover, we present evidence, that transplanted OM but not buccal mucous membrane induced a sustained upregulation of trophic factors at the lesion site. It is concluded that transplantation of OM to the transected facial nerve significantly improves nerve regeneration.

Feasibility of using a video-based motion analysis system for measuring thumb kinematics

While several different methods have been used to measure hand kinematics, fluoroscopy is generally considered to be the most accurate. Recently, video-based motion analysis has been developed for the measurement of joint kinematics. This method is versatile, easy to use, and can measure motions dynamically. Surface markers are most commonly used in the video-based motion systems. However, whether the surface markers placed on the thumb accurately represent the true kinematics of the underlying bony segment is questionable. In this study, the feasibility of surface markers to represent thumb kinematics was investigated by fluoroscopy. Both the positions of surface markers and bony landmarks were simultaneous recorded and then digitized. The Ra 2 values comparing the angular changes of the thumb interphalangeal, metacarpal and carpometacarpal joints derived using the surface markers or bony landmarks were 0.9986, 0.9730 and 0.9186 in the flexion/extension plane respectively, 0.8837, 0.9697 and 0.8775 in the abduction/adduction plane; and 0.9884, 0.9643 and 0.9431 in the opposition plane. The ranges, mean and standard deviation of the absolute differences between calculated angles of different marker sets were also compared. These data revealed that the similarities of the two different marker techniques throughout the motion cycle were high. The differences between the two methods were also within clinically allowable range of ±5°. It is concluded that the application of the video-based motion analysis system with surface markers to thumb kinematics is warranted.