Article

Joint mechanics after Total Knee Replacement while descending stairs

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Abstract

Background: Modern knee designs do not fully restore the anatomy and kinematics of the natural knee. This study evaluates the kinematic and kinetic changes of well-functioning patients with total knee arthroplasty (TKA) in comparison to a healthy age-matched control group while descending stairs and level walking. The aim was to have a baseline for further investigations of TKA patients with problems. Methods: Fifteen patients satisfied with TKA (8♀/7♂; 66.8 ± 7.4 years; body mass index (BMI) 25.9 ± 2.8 kg/m(2); 2.1 ± 1.3 years postop, LCS Complete) and 17 healthy control subjects (7♀/10♂; 66.6 ± 6.8 years; BMI 25.0 ± 2.2 kg/m(2)) participated in the study. Kinematic (upper and lower body) and kinetic (lower body) data were collected during stair descending (step height 17 cm) and level walking, using an 8-camera Vicon system and 2 force plates. Parameters were compared using a Student t test. Results: Patients after TKA showed significantly lower frontal knee moments and a more externally rotated hip during stance for both level walking and stair descent. There were 31% more significantly different parameters during level walking than during stair descent. Conclusion: The analysis of stair descending in addition to level walking for satisfied patients does not add additional information for the understanding of the kinematic and kinetic changes after TKA. It seems more important to include the kinematics and kinetics of the hip and ankle joint in all 3-dimensional planes.

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... Due to the fact that the reported loading of the knee joint for the same exercise has been shown to vary greatly [16][17][18], this investigation considered the forces operating on the knee as reported by prior studies using in vivo telemetric implants [19,20]. To enable the generation of consistent datasets, load values were normalized in terms of the subject's body weight. ...
Article
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Background Anterior femoral notching ( AFN ) is a severe complication of total knee replacement ( TKR ), which in a percentage of patients may lead to fractures after surgery. The purpose of this study was to investigate the stress distribution in patients with AFN and the safety depth of AFN during the gait cycle. Methods We performed a finite element ( FE ) analysis to analyse the mechanics around the femur during the gait cycle in patients with AFN. An adult volunteer was selected as the basis of the model. The TKR models were established in the 3D reconstruction software to simulate the AFN model during the TKR process, and the 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm AFN models were established, after which the prosthesis was assembled. Three key points of the gait cycle (0°, 22°, and 48°) were selected for the analysis. Results The stress on each osteotomy surface was stable in the 0° phase. In the 22° phase, the maximum equivalent stress at 3 mm was observed. In the 48° phase, with the increase in notch depth, each osteotomy surface showed an overall increasing trend, the stress range was more extended, and the stress was more concentrated. Moreover, the maximum equivalent force value (158.3 MPa) exceeded the yield strength (115.1 MPa) of the femur when the depth of the notch was ≥ 3 mm. Conclusions During the gait cycle, if there is an anterior femoral cortical notch ≥ 3 mm, the stress will be significantly increased, especially at 22° and 48°. The maximum equivalent stress exceeded the femoral yield strength and may increase the risk of periprosthetic fractures.
... Investigations into TKA function during complete gait cycles using skinmarker-based motion analysis have been successful in determining global segment kinematics, thereby allowing the estimation of external joint moments [2][3][4]. However, this approach is known to be strongly affected by soft tissue artefacts [5,6] and does not allow an accurate quantification of tibiofemoral antero-posterior (A-P) translation and internal/external rotation [6][7][8][9]. ...
Article
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Although total knee arthroplasty (TKA) has become a standard surgical procedure for relieving pain, knowledge of the in vivo knee joint kinematics throughout common functional activities of daily living is still missing. The goal of this study was to analyse knee joint motion throughout complete cycles of daily activities in TKA subjects to establish whether a significant difference in joint kinematics occurs between different activities. Using dynamic videofluoroscopy, we assessed tibio-femoral kinematics in six subjects throughout complete cycles of walking, stair descent, sit-to-stand and stand-to-sit. The mean range of condylar anterior–posterior translation exhibited clear task dependency across all subjects. A significantly larger anterior–posterior translation was observed during stair descent compared to level walking and stand-to-sit. Local minima were observed at approximately 30° flexion for different tasks, which were more prominent during loaded task phases. This characteristic is likely to correspond to the specific design of the implant. From the data presented in this study, it is clear that the flexion angle alone cannot fully explain tibio-femoral implant kinematics. As a result, it seems that the assessment of complete cycles of the most frequent functional activities is imperative when evaluating the behaviour of a TKA design in vivo.
... A more comprehensive analysis of the differences of knee joint biomechanics after TKA as compared to healthy controls has been achieved in other studies by three dimensional motion analysis (Andriacchi et al., 1982, Bolanos et al., 1998, Lee et al., 1999, Otsuki et al., 1999, Saari et al., 2005, Fenner et al., 2017. The most common findings were reduced stance knee flexion and abnormal patterns of external flexion/extension moment of the knee (Andriacchi et al., 1982, Milner, 2009, McClelland et al., 2011, Levinger et al., 2012b. ...
Conference Paper
End-stage osteoarthritis (OA) requires joint replacement surgery. Although total knee arthroplasty (TKA) usually relieves pain, some patients are disappointed with their mobility, which may result from an abnormal gait. Post-operative physiotherapy following TKA is essential, although little consensus exists regarding longer-term rehabilitation. Typical rehabilitation has an internal focus on specific muscles and joints, but task-orientated rehabilitation (TOR) may be more effective. This study tested the hypothesis that TOR can improve gait and patient reported functional outcome following TKA. Seventy six patients were studied 12 months after TKA during follow up at the Royal National Orthopaedic Hospital, Stanmore. Patient reported functional outcome was assessed using the Oxford Knee Score (OKS) and gait characteristics were measured using inertial measurement units (IMUs). A subset of 21 patients, exhibiting abnormal gait, entered a 4-week TOR programme, based on daily walking and stair climbing. Patients were re-assessed with OKS and IMUs, and gait quantity compared pre- and post-intervention using pedometers. A subset of 4 patients’ baseline gaits was compared to 5 controls, and to their own gait following the TOR, while subjected to differing treadmill conditions. Multiple regression analysis showed that stride duration significantly predicted OKS (p<0.0001, n=76). Higher OKS was observed in patients who have shorter stride duration, which was in turn a result of greater RoM of the leg joints and segments in the sagittal plane. TKA patients’ response to the varying treadmill conditions was similar, but inferior in the gait parameters’ values as compared to the healthy participants. Following TOR, 21 patients exhibited a significantly higher OKS (p=0.001, n=21). Stride duration, thigh, knee and calf sagittal range of motion and knee flexion in stance significantly increased in both limbs following TOR. In conclusion, the results indicate that there is scope to improve rehabilitation of patients after TKA. TOR improves gait quality and therefore has the potential to improve satisfaction in TKA patients.
... However, a recent study showed that small deviations from the static mechanical axis alignment in TKA did not appear to impact overall survivorship or complication rates at short-term follow-up [8]. Moreover, some studies demonstrated that knee kinematics during gait in TKA group still differed from those of healthy control group despite of improved clinical outcomes and spatiotemporal parameters [9,10]. ...
Article
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Purpose With the aim of investigating the spatiotemporal features of early gait pattern and knee kinematics after total knee arthroplasty and analyzing the association between outcomes of gait analyses and knee kinematic parameters, the relationship between walking and dynamic knee deformity at the early period after total knee arthroplasty was assessed in this study. Methods Eighteen patients including 14 women and 4 men who underwent total knee arthroplasty were analyzed using three-dimensional gait analysis system to observe gait parameters and values of maximum knee flexion angle (MKFA) during swing phase and knee flexion angle (KFA) and knee valgus angle (KVA) at midstance phase. Results 3D gait analysis showed that operated side exhibited significantly less total support time and single support time as well as significantly longer swing phase compared with the other side. During walking, the operated side had significantly smaller MKFA and greater KFA and KVA than the nonoperated side. There was moderate to significant correlation between gait pattern and the dynamic knee kinematics. Conclusion The gait abnormality of patients after TKA was associated with inadequate flexion of knees at swing phase and insufficient extension at stance phase as well as increased range of valgus.
Article
Background Many total knee replacement (TKR) patients need to have a contralateral knee replacement. Biomechanical differences between first and second replaced limbs of bilateral TKR have not been examined during stair negotiation. Additionally, it is unknown whether hip and ankle biomechanics of bilateral patients are altered. We examined hip, knee, and ankle biomechanics of first and second replaced limbs bilateral patients, as well as replaced and non-replaced limbs of unilateral patients, during stair ascent and descent. Methods Eleven bilateral TKR patients (70.09 ± 5.41 years, 1.71 ± 0.08 m, 91.78 ± 13.00 kg) and 15 unilateral TKR patients (64.93 ± 5.11 years, 1.75 ± 0.09 m, 89.18 ± 17.55 kg) were recruited. Patients performed three to five trials of stair ascent and descent. The second step, during ascent, was the step of interest when analyzing each limb. A 2 × 2 (limb × group) analysis of variance was performed to determine differences between limbs and groups. Results During ascent, bilateral patients exhibited decreased peak loading-response knee extension (KEM) and push-off plantarflexion moments. Unilateral replaced limb KEM was lower than non-replaced limbs. During descent, bilateral patients descended the staircase significantly slower, had lower peak loading-response vertical ground reaction force and KEM, and push-off KEM. Bilateral patients had higher peak loading-response hip extension and push-off plantarflexion moments, and increased knee adduction ROM, compared with unilateral TKA patients. Conclusions Bilateral patients exhibited similar hip, knee, and ankle joint moments between first and second replaced limbs. Substantial differences in hip, knee, and ankle biomechanics during stair negotiation in bilateral patients compared with unilateral patients may indicate a more complex adaptation strategy present in these patients.
Article
Introduction: Many patient-reported outcome measures (PROMs) have been utilized to assess outcomes after unicompartmental knee arthroplasty (UKA). However, most are not specifically designed for UKA and the measurement properties of these PROMs have never been elucidated in the setting of UKA. This study aimed to evaluate the reliability and validity of commonly used PROMs after UKA, which includes the Oxford knee score (OKS), Knee Society Score (KSS)-function score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Knee Injury and Osteoarthritis Outcome Score (KOOS). Hypothesis: The four commonly used PROMs after UKA are of good reliability and validity, but with different floor/ceiling effect. Material and methods: Prospectively collected postoperative follow-up PROMs scores of patients after medial UKA cases for osteoarthritis between May 2015 and June 2018 were retrospectively analyzed. All of the PROMs were finished on the same electronic questionnaires. Reliability (internal consistency, test-retest reliability, measurement error), construct validity and floor/ceiling effects were assessed. Results: The whole cohort was composed of 207 cases, with a median age of 62.0 years and a male ratio of 59/207 (28.50%). Internal consistency was high in the OKS, weak in the KSS-function score and with redundancy in the WOMAC and KOOS scores (Cronbach alpha=0.915, 0.610, 0.953, 0.961, respectively). Each of the four PROMs had a high test-retest reliability (all intraclass correlation coefficient (ICC) >0.97). Convergent validity of the four PROMs with the physical component score of the 12-Item Short Form Health Survey (SF-12 PCS) were proven (all r >0.5; p<0.001). While no ceiling effect occurred in the OKS, one was detected in the KSS-function score with 19.81% of patients achieving the best possible score, as well as in the WOMAC sub-score for pain (54.11%) and stiffness (50.72%), in addition to the KOOS sub-score for symptoms (27.54%) and pain (38.16%). Discussion: The four commonly used PROMs after UKA showed good test-retest reliability and construct validity. The OKS is more recommended for its better performance in internal consistency and ceiling effect than the KSS-function score, the WOMAC and KOOS scores. Level of evidence: III; Diagnostic study.
Article
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Introduction Eccentric (negative) resistance exercise of the legs using specialized machines has been reported to be useful and often superior to standard exercise following total knee arthroplasty (TKA). Movements that utilize body mass and gravity as a mode of eccentric resistance exercise in a more pragmatic rehabilitation paradigm may also be useful in reversing chronic muscle impairments observed years following surgery. This study explores whether an eccentrically biased, body mass resistance exercise induces greater magnitude of sagittal plane extensor angular impulse of the support torque and individual net joint torque contributions during both squatting and lunging movement patterns 6 weeks following TKA. Methods Cross-sectional laboratory-based study design including 10 patients following primary unilateral TKA (6.5 ± 0.8 weeks.). All patients completed 3 trials of the squat and lunge movement pattern under both a concentric and an eccentric condition. Extensor angular impulse of the support torque and net joint torque contributions were calculated by integrating the joint torque versus time curves. A Two-way analysis of covariance was conducted and contracts of clinical interest were computed using Wald posttest. P Values for all pairwise comparisons were adjusted for multiplicity using Bonferroni multiple comparison procedure. Results The eccentric condition, compared to the concentric condition, displayed larger magnitude of extensor angular impulse during both the squat (P < .001) and lunge (P < .001) movement patterns for the support torques. Similarly, the eccentric condition, compared to the concentric condition, displayed larger magnitude of extensor angular impulse of the hip, knee, and ankle (P < .001) during both movement patterns. Conclusion Eccentrically biased, body mass movement exercises can produce higher levels of extensor angular impulse on the surgical limb in patients early after TKA. Patients in this study were able to tolerate the higher extensor angular impulse demands and performed the eccentrically biased conditions (without specialized machines) that could be beneficial in postoperative rehabilitation.
Article
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Copyright: © 2014 Fenner V, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract The ability to climb stairs is a highly demanding task for the musculoskeletal system, and gait adaptations after total knee arthroplasty (TKA) might be more pronounced during stair climbing than during level walking. The purpose of this study was to compare full body kinematics and kinetics between patients with good functioning TKA and a healthy control group during stair ascending and level walking. Eighteen patients after TKA (67.8 ± 8.1 yrs) and 20 age-matched healthy controls (66.1 ± 6.4 yrs) participated in this study. Full body kinematic and kinetic data was collected during stair ascending and level walking. Patients after TKA showed differences in sagittal plane knee moments during both stair ascending and level walking compared to the controls. The hip of the patients was more externally rotated in both conditions (p<0.001), although there were no differences in the passive range of motion (p=0.630). The trunk angles only showed a few deviations between patients and controls. Differences between patients and controls were found more often during level walking than during stair ascending. The study shows that considering adjacent joints gives more additional information for treatment recommendations than the additional analysis of the trunk when comparing patients after TKA to healthy seniors. To reduce the higher knee flexion moment during stair ascending in patients, we recommend the strengthening of the calf muscles. It seems that stair ascending does not provide additional information to guide actual treatment recommendations compared to level walking alone.
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The purpose of this review was to summarize the biomechanical adaptations during stair ambulation that occur after total knee arthroplasty (TKA). Articles were identified by searching PubMed and Web of Science. During stair ascent, knee flexion angle at heel strike and walking velocity were reduced in TKA subjects compared to controls. Results of other variables were not consistent between studies. During stair descent only one study found any differences for knee moments in the sagittal and frontal plane between TKA subjects and controls. Other results during stair descent were not consistent between studies. Differences in methods can partially explain discrepancies between studies in this review. More studies with consistent and improved methods are needed in order to provide better understanding of stair ambulation following TKA.
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Three-dimensional kinematic measures of gait are routinely used in clinical gait analysis and provide a key outcome measure for gait research and clinical practice. This systematic review identifies and evaluates current evidence for the inter-session and inter-assessor reliability of three-dimensional kinematic gait analysis (3DGA) data. A targeted search strategy identified reports that fulfilled the search criteria. The quality of full-text reports were tabulated and evaluated for quality using a customised critical appraisal tool. Fifteen full manuscripts and eight abstracts were included. Studies addressed both within-assessor and between-assessor reliability, with most examining healthy adults. Four full-text reports evaluated reliability in people with gait pathologies. The highest reliability indices occurred in the hip and knee in the sagittal plane, with lowest errors in pelvic rotation and obliquity and hip abduction. Lowest reliability and highest error frequently occurred in the hip and knee transverse plane. Methodological quality varied, with key limitations in sample descriptions and strategies for statistical analysis. Reported reliability indices and error magnitudes varied across gait variables and studies. Most studies providing estimates of data error reported values (S.D. or S.E.) of less than 5 degrees , with the exception of hip and knee rotation. This review provides evidence that clinically acceptable errors are possible in gait analysis. Variability between studies, however, suggests that they are not always achieved.
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Manual muscle testing with the examiner providing the resistance has long been a standard test of muscle strength. Through the use of extremities acting as levers, clinicians have been able to effectively apply resistance to all muscle groups except the ankle plantar flexors. As a result, a standing heel-rise test that uses body weight as the resistance has been substituted. The number of heel-rises that represent normal plantar-flexor "strength" and the ability of subjects to repeatedly use that "strength" remain unresolved. Because walking is an endurance task, the hypothesis tested by this study was that individuals without known weakness would be able to perform more than the standard recommended one to five standing heel-rises. The purpose of this study was to measure the number of standing heel-rises that individuals without known weakness could accomplish. Two hundred three subjects were studied for their ability to do standing heel-rises, as is done when testing plantar-flexion strength using the upright test. There were 122 male subjects and 81 female subjects, ranging in age from 20 to 59 years. Each subject was asked to do as many standing heel-rises as he or she could, with careful monitoring of body and limb alignment and of ankle motion, with specific criteria for stopping. The average number of heel-rises was 27.9 (SD = 11.1, minimum = 6, maximum = 70) for all groups and both genders, with no differences between male and female subjects. The lower 99% confidence interval was 25. A recommendation is made to change the standard of testing plantar-flexion function, when using the standing heel-rise test, to require 25 repetitions for a grade of Normal. [Lunsford BR, Perry J. The standing heel-rise test for ankle plantar flexion: criterion for normal.
Article
Anatomic and mechanical factors that affect loading in the knee joint can contribute to pathologic changes seen at the knee in degenerative joint disease and should be considered in treatment planning. The objectives of this study were to quantify the relationships between the alignment of the bones of the lower extremity, foot progression angle, and knee adduction moment, and to determine the reliability of our gait measurements. Gait analysis and complete radiographic evaluation of the lower extremity were performed on 11 healthy subjects. The gait measurements were recorded with an optoelectronic digitizer and a multi-component force plate. The subjects who had radiographic measurements indicative of varus alignment of the lower extremity had statistically higher peaks in knee adduction moment in early stance. Conversely, those with valgus alignment of the lower extremity had statistically lower peaks in knee adduction moment in early stance. The subjects who had a large toe-out angle and low ankle inversion moment peaks in late stance had significantly lower peaks in knee adduction moment in late stance. These significant (low to moderate) correlations suggest that the limbs with more valgus alignment and those with a toe-out gait exhibited a reduced peak adduction moment at the knee. To verify the reproducibility of the data, gait analysis testing was performed on each lower limb on 2 separate days for each subject. Analysis of variance showed that there was no significant difference between test limbs or test days for each subject. Our results suggest that the alignment of the lower limb and the foot progression angle, which can be readily measured in a clinical setting, can serve as predictors of knee joint loading in healthy individuals. These findings may have important implications for both surgical and nonsurgical treatment of abnormalities of the knee joint.
Article
We report a prospective study of gait and tibial component migration in 45 patients with osteoarthritis treated by total knee arthroplasty (TKA). Migration was measured over two years using roentgen stereophotogrammetry. We used the previously established threshold of 200 μm migration in the second postoperative year to distinguish two groups: a risk group of 15 patients and a stable group of 28 patients. We performed gait analysis before operation and at six months and at two years after TKA. On all three occasions we found significant differences between the two groups in the mean sagittal plane moments of the knee joint. The risk group walked with higher peak flexion moments than the stable group. The two groups were not discriminated by any clinical or radiological criteria or other gait characteristics. The relationship which we have found between gait with increased flexion moments and risk of tibial component loosening warrants further study as regards the aetiology of prosthetic loosening and possible methods of influencing its incidence.
Article
Fourteen patients with a posterior-stabilized prosthesis in one knee and a posterior cruciate-retaining prosthesis in the contralateral knee and both scoring good or excellent on the Hospital for Special Surgery (HSS) knee scale were evaluated by isokinetic muscle testing and comprehensive gait analysis at a mean follow-up of 98 months after arthroplasty. The average HSS knee score (93 points) and the average Knee Society score (94 points) were the same for the cruciate-retaining and posterior-stabilized knees. No differences were noted between the cruciate-retaining and the posterior stabilized knees with respect to isokinetic muscle testing parameters (peak torque, endurance, angle of peak torque, and torque acceleration energy) for both quadriceps and hamstrings. No significant differences were found between the cruciate-retaining and the posterior-stabilized knees with regard to gait parameters, knee range of motion, and electromyographic waveforms during level walking and stair climbing. Cruciate-retaining and posterior-stabilized total knee prostheses perform equally well during level gait and stair climbing.
Article
OBJECTIVE: The purpose of this study was to compare tibiocalcaneal motion during running based on skeletal markers with tibiocalcaneal motion based on external markers. DESIGN. IN VIVO: measurements of external and skeletal tibiocalcaneal kinematics. BACKGROUND: External (shoe, skin) markers are typically used to determine rearfoot kinematics. However, it is not known if such markers are able to provide a good representation of the skeletal (tibiocalcaneal) kinematics. METHODS: Bone pins were inserted into the tibia and calcaneus of five subjects. The 3-D motion of markers attached to bone pins as well as of external markers attached to the shank and shoe were determined during the stance phase of five running trials. Intersegmental motion was expressed in terms of Cardan angles (plantarflexion/dorsiflexion, abduction/adduction, inversion/eversion). RESULTS: It was found that the skeletal inversion/eversion, abduction/adduction, and plantarflexion/dorsiflexion motions were similar across the subjects. The shape of the tibiocalcaneal rotation curves based on external markers were similar to those based on bone markers. However, the rotations were generally overestimated when using external markers, e.g. the average maximal eversion motion calculated from external markers was 16.0 degrees whereas the skeletal maximal eversion motion was only 8.6 degrees. These discrepancies were mainly due to the relative movement between shoe markers and underlying calcaneus. CONCLUSIONS: External markers are only gross indicators of the skeletal tibiocalcaneal motion. The rotations derived from external shoe and shank markers typically overestimate the skeletal tibiocalcaneal kinematics. RELEVANCE: Quantitative results determined from external markers have to be used with caution. For tibiocalcaneal rotations, external markers may be used to show trends, but absolute values cannot be trusted.
Article
The aim of this study was to investigate the biomechanics and motor co-ordination in humans during stair climbing at different inclinations. Ten normal subjects ascended and descended a five-step staircase at three different inclinations (24 degrees, 30 degrees, 42 degrees ). Three steps were instrumented with force sensors and provided 6 dof ground reactions. Kinematics was analysed by a camera-based optoelectronic system. An inverse dynamics approach was applied to compute joint moments and powers. The different kinematic and kinetic patterns of stair ascent and descent were analysed and compared to level walking patterns. Temporal gait cycle parameters and ground reactions were not significantly affected by staircase inclination. Joint angles and moments showed a relatively low but significant dependency on the inclination. A large influence was observed in joint powers. This can be related to the varying amount of potential energy that has to be produced (during ascent) or absorbed (during descent) by the muscles. The kinematics and kinetics of staircase walking differ considerably from level walking. Interestingly, no definite signs could be found indicating that there is an adaptation or shift in the motor patterns when moving from level to stair walking. This can be clearly seen in the foot placement: compared to level walking, the forefoot strikes the ground first--independent from climbing direction and inclination. This and further findings suggest that there is a certain inclination angle or angular range where subjects do switch between a level walking and a stair walking gait pattern.
Article
The movement of the centre of mass in the vertical and lateral directions during gait in children with myelomeningocele was analyzed. The children were classified into five groups depending on the successive paresis of lower limb muscle groups and compared to a control group. In the groups with dorsi- and plantarflexor weakness, the excursions increased and an anterior trend in the centre of mass was observed. In the groups with additional abductor paresis, the lateral excursion was highest and the vertical excursion low due to increased transverse and frontal motion and reduced sagittal motion. With further paresis of the hip extensors, the centre of mass was more posteriorly positioned due to compensatory trunk extension. Improved understanding of individual children's solutions to their muscle paresis can be obtained by visualizing the centre of mass relative to the pelvis. Centre of mass analyses in myelomeningocele offer an important complement to standard gait analysis.
Article
To quantify the locomotor deficits before and 2 months after a total knee arthroplasty (TKA) in patients with osteoarthritis of the knee, and to compare pre- and postoperative performance. Locomotor capacity of patients was evaluated using laboratory gait and stair-ascent evaluations (kinematic and kinetic variables, electromyographic activity of 4 muscles of both lower limbs, and spatiotemporal parameters), the timed Up & Go (TUG), and the 6-minute walk (6MW) test. Large locomotor deficits (increased hip flexion, decreased excursions of the knee and ankle, smaller extensor and flexor moments of force at the 3 joints, and muscle activation levels lower in all muscles tested) are still present in patients, particularly in the single-limb support subphase before and 2 months after TKA. These deficits explain the slower walk and stair-ascent speeds and a reduced performance at the TUG and 6MW tests. These results emphasize the need for more careful followup and intensive rehabilitation programs in the first months following TKA.
Article
The external knee adduction moment during walking and stair climbing has a characteristic double hump pattern. The magnitude of the adduction moment is associated with the development and progression of medial compartment knee osteoarthritis (OA). There is an inverse relationship between the magnitude of the second peak adduction moment and foot progression angle (FPA). Increasing FPA beyond a self-selected degree of toe-out may further reduce the magnitude of this moment for persons with knee OA. In this study, subjects with medial compartment knee OA walked and climbed stairs using their natural (i.e. self-selected) and an increased FPA (i.e. self-selected+15 degrees of additional toe-out). Increasing FPA did not change the magnitude of the first peak adduction moment but it did significantly decrease the second peak during walking. The first peak moment during stair ascent was significantly greater for the increased FPA condition, and a significant reduction was noted for the second peak. No significant differences were noted during stair descent. These results suggest that walking with a toe-out strategy may benefit persons with early stages of medial knee OA.
Article
Gait analysis has been used to objectively measure patients' function following total knee replacement (TKR). Whilst the findings of this research may have important implications for the understanding of the outcomes of TKR, the methodology of existing research appears to be diverse and many of the results inconsistent. The objective of this systematic review was to synthesise reported findings and to summarise the methods used by researchers in this field. Eleven articles published in the medical literature that used gait analysis to compare patients following TKR with controls were identified for inclusion in this review. Each article was assessed for methodologic quality and data was compared across studies through the calculation of effect sizes. Consistently large effect sizes showed that patients following TKR walk with less total knee motion during gait and with less knee flexion during swing than controls. Kinetic discrepancies between patients and controls were also identified. The substantial methodologic differences between studies may contribute to the inconsistencies in reported findings for many gait outcomes. Future research is needed to determine the clinical relevance of these findings.
Tibiocalcaneal motion during running, measured with external and bone markers
  • C Reinschmidt
  • Van Den
  • A J Bogert
  • N Murphy
Reinschmidt C, van Den Bogert AJ, Murphy N, et al. Tibiocalcaneal motion during running, measured with external and bone markers. Clin Biomech 1997;12:8.
Untersuchungstechniken nach Daniels und Worthingham. 8. Auflage. München: Urban&Fischer in Elsevier
  • H J Hislop
  • J Montgomery
  • Manuelle Muskeltests
Hislop HJ, Montgomery J. Manuelle Muskeltests. Untersuchungstechniken nach Daniels und Worthingham. 8. Auflage. München: Urban&Fischer in Elsevier; 2007. ISBN: 13-978-3-437-31340-0.
Joint load during gait in adolescents with tibial malalignment
  • V Fenner
  • T Urech
  • K Zdenek
Fenner V, Urech T, Zdenek K, et al. Joint load during gait in adolescents with tibial malalignment. 27th Annu Meet Children's Orthopaedics, Augsburg, March 1-2. J Children's Orthopaedics 2013;7:331.