Gait analysis is an indispensable tool for scientific assessment and treatment of individuals whose ability to walk is impaired. The high cost of installation and operation are a major limitation for wide-spread use in clinical routine. Advances in Artificial Intelligence (AI) could significantly reduce the required instrumentation. A mobile phone could be all equipment necessary for 3D gait analysis. MediaPipe Pose provided by Google Research is such a Machine Learning approach for human body tracking from monocular RGB video frames that is detecting 3D-landmarks of the human body. Aim of this study was to analyze the accuracy of gait phase detection based on the joint landmarks identified by the AI system. Motion data from 10 healthy volunteers walking on a treadmill with a fixed speed of 4.5km/h (Callis, Sprintex, Germany) was sampled with a mobile phone (iPhone SE 2nd Generation, Apple). The video was processed with Mediapipe Pose (Version 0.9.1.0) using custom python software. Gait phases (Initial Contact - IC and Toe Off - TO) were detected from the angular velocities of the lower legs. For the determination of ground truth, the movement was simultaneously recorded with the AS-200 System (LaiTronic GmbH, Innsbruck, Austria). The number of detected strides, the error in IC detection and stance phase duration was calculated. In total, 1692 strides were detected from the reference system during the trials from which the AI-system identified 679 strides. The absolute mean error (AME) in IC detection was 39.3 ± 36.6 ms while the AME for stance duration was 187.6 ± 140 ms. Landmark detection is a challenging task for the AI-system as can clearly be seen be the rate of only 40% detected strides. As mentioned by Fadillioglu et al., error in TO-detection is higher than in IC-detection

The Step Holter is a software and mobile application that can be used to easily study gait analysis. The application can be downloaded for free on the App Store and Google Play Store for iOS and Android devices. The software can detect with an easy calibration the three planes to detect the movement of the gait. Before proceeding with the calibration, the smartphone can be placed and fixed with a band or stowed into a long sock with its top edge at the height of the joint line, in the medial side of the tibia. The calibration consists in bending the knee about 20 to 30 degrees and then making a rotation movement, leaving the heel fixed to the ground as a rotation fulcrum. After calibration, the program records data related to lateral flexion, rotation, and bending of the leg. This data can be viewed directly from the smartphone screen or transmitted via a web link to the Step Holter web page . www.stepholter.com. by scanning a personal QR code. The web page allows the users to monitor the test during its execution or view data for tests done previously. By pressing the play button, it is possible to see a simulation of the patient's leg and its movement. With the analyze button, the program is capable of calculating the swing and stance phase of every single step, providing a plot with time and percentages. Finally, with the Get Excel button, test data can be conveniently exported for more in-depth research. The advantage of this application is not only to reduce the costs of a machine for the study of gait analysis but also being able to perform tests quickly, without expensive hardware or software and be used in specific spaces, without specialized personnel. Furthermore, the application can collect important data concerning rotation that cannot be highlighted with the classic gait analysis. The versatility of a smartphone allows tests to be carried out not only during walking but also by climbing or descending stairs or sitting down or getting up from a chair. This software offers the possibility to easily study any kind of patients; Older patients, reluctant to leave their homes for a gait analysis can be tested at home or during an office control visit. Step Holter could be one small step for patients, one giant leap for gait study simplicity. For any figures or tables, please contact authors directly

Introduction: It has been proposed that rotational gait abnormalities in the normal child are usually reflections of the anatomic deformity. A decreased acetabular and femoral anteversion have been recognized as a predisposing factor for osteoarthritis of the hip and the McKibbin instability index was introduced to quantify this relationship. Additionally, an increased femoral anteversion has been associated with osteoarthritis of the knee. However, it is well known that compensatory factors influence the dynamic rotational profile during gait. We compared rotational computed tomography data with gait analysis to evaluate their correlation and to elucidate the influence of compensatory mechanisms. Materials and Methods: In a prospective study conducted between 2001 and 2005 patients presenting with rotational malalignment were sent for 3D gait analysis. Main exclusion criterion was any kind of neurological affection. Patients in whom surgery was considered were referred to rotational computed tomography. The rotational alignment of the pelvis, hip and knee at different times during the gait cycle as evaluated in the 3D gait analysis was compared to the angular values derived from the rotational computed tomography for the femur and tibia and statistically analyzed and correlated. Results: There were 12 female and 16 male patients with a mean age of 16 (± 9.7) years at the time of gait analysis. After a first evaluation of data 8 limb segments were excluded to increase the quality of data. The mean anteversion of the femur was 29 degrees (2 degrees of retrotorsion to 56 degrees of anteversion) and the mean tibial torsion was 31 degrees (1 to 66 degrees of external torsion). The calculation of the Pearson correlation showed that an increase of femoral anteversion resulted in an increase of pelvic range of motion. An increase of femoral anteversion resulted in an increase of the internal rotation of the hip. Highly significant correlations were found between the rotational–CT values for the tibia and the all parameters describing rotation of the knee. The determination coefficient was high for tibial torsion versus knee rotation (R2 = 0.64), but showed a low value for femoral anteversion versus hip rotation (R2 = 0.2). Conclusion: The rotation of the hip as found in the gait analysis showed only weak correlation with rotational CT data. This is not surprising as the hips segment offers many possibilities for compensation. The torsion of the tibia was found to correlate very strongly with the gait analysis. The McKibbin index seems questionable as a prognostic factor for the individual patient in the light of a multitude of dynamic compensatory influences. Effort should be made to integrate the static instability index with dynamic gait analysis data

Total knee replacement in a commonly performed procedure in the United Kingdom with more than 76000 primary procedures performed in 2010. With so many procedures performed there has to be a robust way of assessing the outcome of the procedure. Gait analysis is a valuable tool in objectively assessing the these patients. Inertial movement units (IMU's) are a fairly new development in gait analysis. The aim of our project is to use IMUs to assess the differences in gait profile between a cohort of healthy controls, a group of pre operative knee replacement patients, a group of 8 week post operative patients and finally a group of post operative knee replacement patients at 1 year. We studied a total of 47 patients. We also had data from a previous study done on healthy controls using the same measurement tool. We measured three parameters: peak swing phase flexion, peak stance phase flexion and stride duration. Our findings indicate that pre-operative patients have a significantly reduced peak flexion in swing and stance with increased stride duration. This shows no improvement at the 8 week mark. At the 1 year mark peak flexion in swing returns to pre operative levels but flexion in stance and stride duration are still poor. These findings may not have been identified without gait analysis. Gait analysis using intertial movement units will add much information to radiographs and clinical examination. This information can also be used to tailor individual patients rehabilitation

Patellofemoral osteoarthritis (PFOA) affects 32% men and 36% women over the age of 60years and is associated with anterior knee pain, stiffness, and poor mobility. Patellofemoral arthroplasty (PFA) is a bone-sparing treatment for isolated PFOA. This study set out to investigate the relationship between patient-related outcome measures (PROMs) and measurements obtained from gait analysis before and after PFA. There are currently no studies relating to gait analysis and PFA available in the literature. A prospective cohort study was conducted of ten patients known to have isolated PFOA who had undergone PFA compared to a gender and age matched control group. The patients were also asked to complete questionnaires (Oxford knee score (OKS), EQ-5D-5L) before surgery and one year after surgery. Gait analysis was done on an instrumented treadmill comparing Ground reaction force parameters between the control and pre and post-operative PFA patients. The average age 60 (49–69) years with a female to male ratio of 9:1. Patient and healthy subjects were matched for age and gender, with no significant difference in BMI. Post-op PFA improvement in gait seen in ground reaction force at 6.5km/h. Base support difference was statistically significant both on the flat P=0.0001 and uphill P=0.429 (5% inclination) and P=0.0062 (10% inclination). PROMS response rate was 70%(7/10) pre-operative and 60%(6/10) post-operative. EQ-5D-5L scores reflected patient health state was better post-operatively. This study found that gait analysis provides an objective measure of functional gait and reflected by significant quality-of-life improvement of patients post PFA. Literature lacks studies relating to gait-analysis and PFA. Valuable information provided by this study highlights that PFA has a beneficial outcome reflected by PROMs and improvement in vertical ground reaction force and gait. Further research is needed to assess how care-providers may use gait-analysis as part of patient care plans for PFOA patients

Total hip arthroplasty (THA) is one of the most successful surgery. However, patients' expectations have increased over the last two decades in regards to hip function after joint replacement, the patients assume to return their daily and sport activities without major limitations. This presentation will examine the effect of surgical approaches and implant designs as well as rehabilitation protocol on the clinical and biomechanical outcomes after THA. The new implant designs for THA aim to improve joint function whereas the surgical approaches intend to reduce muscle damage to regain muscle strength. One important determinant measured from gait analysis is the hip abduction moment as the abductors play a key role in stabilizing the pelvis in the frontal plane, particularly in phases of transition, such as the single leg stance in walking or stair climbing. This showed that muscle strength needs to be preserved. To minimize the risk of hip joint instability, a strong focus of implant development has been carried out. To illustrate this important concept within the context of gait analysis, I will present two studies that examine the influence of surgical approach and biomechanical reconstruction; and the second, is a prospective RCT comparing a dual mobility implant to a standard total hip replacement

Total Knee Arthroplasty (TKA) has been widely performed and successful clinical outcomes have been achieved for the patients with knee osteoarthritis which is generally known to cause ADL problem. Clinical and radiographic evaluations are commonly used when evaluating postoperative outcomes, among which kinetic analysis and gait analysis are considered essential to investigate the more detailed effect of the treatment. There is a controversy whether performing TKA on both knees simultaneously is appropriate in treating patients with bilateral knee osteoarthritis, in terms of the speed and effectiveness of gait recovery. In this study, we reviewed the significance of performing simultaneous bilateral TKA, by the results of preoperative and postoperative gait analysis. Materials and Methods: Total of eight patients, all female and diagnosed of bilateral knee osteoarthritis, were treated with TKA and reviewed. Mean age was 70 years old (60–74). For prosthesis, we used Scorpio NRG PS, and ADVANCE, with cementation for all. No patella was replaced. Some had unilateral TKA, and some were treated bilaterally as needed. We examined distance factors (step length and step width), gait velocity, and gait barycentric factors (single-support phase and Ratio of center of gravity maximum values). We performed the analysis preoperatively, postoperatively at 1 month, 3 months, and 6 months. We used the floor pressure gauge (NITTA CORPORATION) and the three-dimensional motion analysis device (DITECT Co. Ltd) for the analysis. Results: During the six-month follow-ups, six cases were unilateral TKA and two were treated bilaterally. Increase in step length was seen in the unilateral cases, and it decreased in the bilateral cases. Step width decreased in five cases, two cases showed no change, and increased in one case. Gait velocity had increased in all cases. Single-support phase was close to 1 for all the cases. Ratio of center of gravity maximum values, which indicates the movement of centroid during ambulation, the ratio went up for unilateral cases while it showed no change in the bilateral cases. Discussion: Quantitative studies of gait analysis have reported that gait condition had improved after TKA. However, some reported that the gait impairment had remained. Unilateral TKA group showed gait restoration, whereas gait abnormality in either leg was seen in the bilateral group. Gait analysis is effective in determining whether surgeons should perform unilateral TKA or bilateral TKA to the patients with bilateral knee osteoarthritis. Among the gait analysis factors, we consider that Ratio of center of gravity maximum values shows effectively the improvement of the treated knee, gait, and the condition of contralateral knee

Purpose. This study aimed to objectively define gait derangements and changes before and after Tibialis Anterior Tendon Transfer surgery in a group of patients treated using the Ponseti method. Methods. 21 feet in 13 patients with Ponseti treated clubfoot who showed supination in swing on clinical examination, underwent gait analysis before, and approximately 12 months after, Tibialis Anterior Tendon transfer. 3–4 weekly casts were applied prior to the surgery, which was performed by transfer of the complete TA tendon to the lateral cuneiform. A parental satisfaction questionnaire was also completed. Results. In all but one patient, increased supination in swing phase was confirmed on pre-operative gait analysis, with EMG evidence of poor Tibialis Anterior modulation through-out the gait cycle. Post-operatively all patients showed improved positioning at initial contact, with heel strike and an absence of supination, and a decrease in swing phase supination. In all patients, knees were overly flexed at initial contact, some continuing through stance phase; there was no change seen postoperatively. All parents reported marked improvements in gait and activity level post-operatively. Conclusion. Gait analysis can be useful to confirm the need for tibialis anterior tendon transfer. Improved post-operative gait patterns seen by parents and clinicians can be related to objective improvements seen during gait analysis, confirming the benefit of tibialis anterior tendon transfer in appropriate patients

Instrumented gait analysis has evolved into a widely used tool to define and describe abnormalities of gait. It is used as a tool to enhance the performance in sports as well as to measure the effects of conservative or surgical treatment methods. Patients usually walk very slow during gait training, whereas normal data are obtained at regular walking velocity. This may lead to misinterpretations. The purpose of this study was to determine the effects of walking slow towards gait and to establish normal data for “walking slow” on a treadmill. 10 healthy volunteers with no known gait problem underwent training to accommodate to the conditions of treadmill walking. There were 5 females and 5 males. The mean age was 30 [range 22–56] years. Instrumented gait analysis was performed using a camera system (Motion Analysis Systems). Data obtained were processed by OrthotracTM and the proprietary software of our lab. During data acquisition participants were asked to walk at leisure velocity, then they were asked to slow down as much as possible. The normal walking velocity of was 0,99 [range 0,78–1,16] m/s. When asked to walk as slow as possible the walking speed decreased to 0,29 [range 0,14–0,50] m/s. We noted a change in the ratio between swing and stance periods with less swing time, as well as a increase of double limb support time. Step length decreased. Changes in the pattern of motion included delayed and increased peak ankle dorsiflexion and decrease of ankle plantar flexion at initial contact. 3-D motion data for hip and knee also demonstrate noteworthy changes, generally resulting in a decrease of joint excursion. Interpretation of gait data obtained from slow walking patients should consider the effects walking velocity. Locomotion therapy (e.g. for spinal cord injuries) should not force patients into motion patterns that are only found at faster walking velocities

Introduction. Total hip arthroplasty (THA) is the most effective treatment modality for severe arthritis of the hip. Patients report excellent clinical and functional outcomes following THA, including subjective improvement in gait mechanics. However, few studies in the literature have outlined the impact of THA, as well as surgical approach, on gait kinetics and kinematics. Purpose. The purpose of this study was to determine the impact of surgical approach for THA on quantitative gait analysis. Methods. Thirty patients undergoing THA for primary osteoarthritis of the hip were assigned to one of three surgical approaches (10 anterior, 10 posterior, and 10 lateral). A single surgeon performed each individual approach. Each patient received standardized implants at the time of surgery (cementless stem and acetabular component, cobalt chrome femoral head, highly cross-linked liner). Patients underwent 3D gait analysis pre-operatively, and at 6- and 12-weeks following the procedure. At each time point, temporal gait parameters, kinetics, and kinematics were compared. Statistical analysis was performed using one-way analysis of variance. Results. All three groups were similar with respect to age (p=0.27), body mass index (p=0.16), and the Charlson Comorbidity Index (p=0.66). Temporal parameters including step length, stride length, gait velocity, and percent stance and swing phase were similar between the groups at all time points. The lateral cohort had higher pelvic tilt during stance on the affected leg than the anterior cohort at 6-weeks (p=0.033). Affected leg ipsilateral trunk lean during stance was higher in the lateral group at 6-weeks (p=0.006) and 12-weeks (p=0.037) compared to the other cohorts. The anterior and posterior groups demonstrated an increased external rotation moment at 6-weeks (p=0.001) and 12-weeks (p=0.005) compared to the lateral group. Discussion. Although temporal parameters were similar across all groups, some differences in gait kinematics and kinetics exist following THA using different surgical approaches. However, the clinical relevance based on the small magnitude of the differences remains in question

Introduction. Various rehabilitation shoes are prescribed to protect the forefoot following surgery. Patients often complain of discomfort in other areas as a result of the postoperative shoe, including the knee, hip and lower back. This has never been quantified. This study aims to establish the effect on other joints using gait analysis. Methods: 11 healthy volunteers were investigated using various common types of postoperative shoe. They were studied with gait analysis equipment and the joint motion assessed with commercial software. The effect of commercial devices designed to minimise gait changes by lifting the contralateral foot were also evaluated. Results. There was a reduction in knee flexion and extension compared to the contralateral leg in all phases of the gait cycle. This was the case with both heel wedge shoes and inflatable air boots. There was also an increase in pelvic tilt during gait with both shoes, which was more pronounced with the air boot. The foot raise device for the contralateral foot which is designed to decrease these changes was effective in decreasing gait changes. Discussion. The use of rehabilitation shoes after forefoot surgery is almost universal. Patients are rarely counselled of the risk of joint pain or back pain as a result of the postoperative shoe. Patients with pre-existing back pain or hip pain may have fewer symptoms if they are supplied with an equalising device to raise the other foot. Conclusions. Patients are at risk of initiation or exacerbation of low back pain or lower limb joint pain from the use of postoperative shoes. Patients with a history of back or limb symptoms should be provided with an equalising device for the contralateral limb to minimise their discomfort. Patients should be warned of this risk when giving consent

Introduction:. There is paucity of literature on Gait analysis following Total Ankle Replacement (TAR). We aimed to study changes to gait after successful Mobility TAR. Methods:. 20 patients who underwent a primary TAR, with a diagnosis of either OA or PTOA were recruited between October 2008 and March 2011. Gait analysis was carried out using the Helen Hayes marker system with VICON 3D opto-electric system pre-operatively, 3, 6 and 12 months post-operatively. Ankle kinematics and spatio-temporal parameters of gait were studied. Results:. 20 patients were included. Mean age was 63.6 years (Range 43–84), mean BMI was 29.6 ± 4.08. Diagnosis was OA in 12 (52.2%) and PTOA in 8 (34.8%). Results showed increase in average and maximum range of dorsiflexion from (3° to 7°) and (11° to 17°) respectively from pre-op to 1 year, but statistically not significant (p>0.05). Of the temporal variables, Average Cadence increased from Pre-op to 1 year (102 to 106 steps/min); double support (0.35% to 0.31%), single support (0.41% to 0.39%) and toe off point at gait cycle (63.9% to 62.4%) decreased from pre-op to 1 year, but failed to achieve statistical significance (p>0.05). For distance variables, Step length showed a significant increase from pre-op to 1 year (0.21m/s to 0.58m/s; p<0.001); stride length increased (1.05m/s to 1.13m/s), step time and stride time decreased (0.60 secs to 0.58 secs) and (1.19 to 1.14 secs) respectively and Walking speed increased (0.90m/s to 1.00m/s) from pre-op to 1 year, but statistically not significant (P>0.05). Conclusion:. There was significant improvement in step length after TAR from pre-op to 1 year. Although the results showed a trend for improvement in average dorsiflexion, average cadence, stride length, walking speed, decreased step and stride length times, which showed improvement in walking pattern in these group of patients, but failed to achieve statistical significance

Total hip arthroplasty (THA) is the most effective treatment modality for severe arthritis of the hip. Patients report excellent clinical and functional outcomes following THA, including subjective improvement in gait mechanics. However, few studies in the literature have outlined the impact of surgical approach on gait kinetics and kinematics. The purpose of this study was to determine the impact of surgical approach for THA on quantitative gait analysis. Thirty patients undergoing THA for primary osteoarthritis of the hip were assigned to one of three surgical approaches (10 anterior, 10 posterior, and 10 lateral). A single surgeon performed each individual approach. Each patient received standardised implants at the time of surgery (cementless stem and acetabular component, cobalt chrome femoral head, highly cross-linked liner). Patients underwent 3D gait analysis pre-operatively, and at 6- and 12-weeks following the procedure. At each time point, temporal gait parameters, kinetics, and kinematics were compared. Statistical analysis was performed using one-way analysis of variance. All three groups were similar with respect to age (p=0.27), body mass index (p=0.16), and the Charlson Comorbidity Index (p=0.66). Temporal parameters including step length, stride length, gait velocity, and percent stance and swing phase were similar between the groups at all time points. The lateral cohort had higher pelvic tilt during stance on the affected leg than the anterior cohort at 6-weeks (p=0.033). Affected leg ipsilateral trunk lean during stance was higher in the lateral group at 6-weeks (p=0.006) and 12-weeks (p=0.037) compared to the other cohorts. The anterior and posterior groups demonstrated an increased external rotation moment at 6-weeks (p=0.001) and 12-weeks (p=0.005) compared to the lateral group. Although temporal parameters were similar across all groups, some differences in gait kinematics and kinetics exist following THA using different surgical approaches. However, the clinical relevance based on the small magnitude of the differences remains in question

We studied the kinematic patterns of knee, performing gait analysis, in diplegic children. Our gait laboratory consists of 4 infrared cameras. We used the Elite program. We studied initially 25 normal children. We constructed our models and developed the linear measurements of the gait. Then we performed measurements of the angles of the knee and ankle joints and the wave forms of the kinematic forms of these joints. We performed gait analysis in 25 diplegic children aged 4–15 years old. We found two groups of children. In the first group (21 children) the main lesion was in the kinematics of the knee and in the second group (4 children) in the ankle joint. In the first group, characteristic pattern is the absence of full extension of the knee during stance. Analyzing the kinematics of the ankle joint of this group, we found 12 children with toe strike and 9 children landing in the whole foot. Studding the wave form of the knee in stance and swing, we separated those with spasticity alone from those with fixed contractures of the knee. Our patients were treated either with botulinum injections or with intamuscular lengthening, according to our results. In the second group, of diplegic children with toe walking, we found increased equinus, both in stance and swing. Kinematic studies of the knee in frontal and coronal level showed increased adduction of the femur( scissoring) and increased anteversion. Gait analysis in diplegic children offers an accurate assessment of the gait disorders. We can plan our treatment according the results of the gait analysis

Background. The aim of this study is to analysis the ability of these patients, treated with MOMHR, to resume sport activities by gait analysis and clinical evaluations. Metal on metal hip resurfacing (MOMHR) is indicated to treat symptomatic hip osteoarthritis in young active patients. These patients require a high level of function and desire to resume sport activities after surgery. Study Design & Methods. 30 consecutive male patients playing high impact sports with unilateral hip osteoarthritis and normal contralateral hip were included in the study, they were treated with MOMHR by the same surgeon. No patients were lost to follow. The mean age at operation was 39.1 years (range 31 to 46). Primary diagnosis was osteoarthritis. OHS, HHS, UCLA activity score were completed at pre-operative time, six months and one year after surgery. Functionally, gait analysis was performed in all patients 6 months and one year after surgery. A stereophotogrammetric system (Smart-DX, BTS, Milano, Italy, 10 cameras, 250Hz) and two platforms (9286BA Kistler Instrumente AG, Switzerland) were used. Cluster of 4 markers were attached on the skin of each bone segment, a number of anatomical landmarks were calibrated and segment anatomical frames defined, markers were positioned by the same operator. Walking, running and squat jump were analyzed and strength and range of movement of the hips and knees were calculated. Results. At follow-up times the survival rate for the whole cohort was 100%. The mean pre-op OHS was 28.1 points (range 15.0 to 38.0), at 6 months after surgery was 44.5 points (range 44 to 48), at one year after surgery was 47.9 points (range 45 to 48). The mean pre-op HHS was 54.7 points (range 33.1 to 73.4), at 6 months after surgery was 96.7 points (range 93.4 to 100), at one year after surgery was 99.7 points (range 95.7 to 100). The mean pre-op UCLA activity score was 2.7 (range 2 to 4), at 6 months after surgery was 7.4 (range 5 to 10), at one year after surgery was 8.6 (range 7 to 10). At 6 months after surgery, patients showed a reduction of the differences between the operated and the contralateral side during walking, running and squat jumping. (p<0.01). One year after the operation there were no differences. At 3 months after surgery the mean hip flexion extension range of motion was in the normal hips 41±1.7 and in the operated hips 37.3±2.1; at 6 months after surgery the mean hip flexion extension range of motion was in the normal hips 45.4±1.8 and in the operated hips 42.0±1.7; At 1 year after surgery the hip flexion extension range of motion was in the normal hips 42.9±1.7 and in the operated hips 45.5±1.4. (p=0.001). Conclusions. Our gait analysis study shows that the biomechanical function of the operated hip is completely recovered 1 year after MOMHR operation. As a consequence sport activities can be successfully resumed. MOMHR is a good choice for young and active patients affected by hip osteoarthritis requiring a high level of activity

Background: Mobile-bearing knee replacements have some theoretical advantages over fixed-bearing devices. However, very few randomized controlled clinical trials have been published to date, and studies showed little clinical and subjective advantages for the mobile-bearing using traditional systems of scoring. The choice of the ideal outcome measure to assess total joint replacement remains a complex issue. However, gait analysis provides objective and quantifying evidences of treatment evaluation. Significant methodological advances are currently made in gait analysis laboratories and ambulatory gait devices are now available. The goal of this study was to provide gait parameters as a new objective method to assess total knee arthroplasty outcome between patients with fixed- and mobile-bearing, using an ambulatory device with minimal sensor configuration. This randomized controlled double-blind study included to date 14 patients: the gait signatures of four patients with mobile-bearing were compared to the gait signatures of nine patients with fixed-bearing pre-operatively and post-operatively at 6 weeks, 3 months and 6 months. Each participant was asked to perform two walking trials of 30m long at his/her preferred speed and to complete a EQ-5D questionnaire, a WOMAC and Knee Society Score (KSS). Lower limbs rotations were measured by four miniature angular rate sensors mounted respectively, on each shank and thigh. A new method for a portable system for gait analysis has been developed with very encouraging results regarding the objective outcome of total knee arthroplasty using mobile- and fixed-bearings

The Arthrotic knee is frequently associated with several-pain and loosening of joint function often so important to need a total knee arthroplasty (TKA). Obviously, the aims of a TKA is to obtain no pain and restore a good joint function so to contribute to a good health and a better quality life. To realize ends like these it’s necessary a good selection of the patients first, an adequate preparation for the surgery, correct surgery technique and a specific post-operative rehabilitation until achieving the normal daily activities. In this way clinical biomechanical evaluations can contribute to quantify the achievement of the ends and they can get influence to modulate the “ways” used. Actually the dynamic evaluation more useful and reproducible in the gonartrhosis is the gait analysis. Patients were selected from a group of subjects suffering from advanced gonartrhosis. Exclusion criteria from the study were: bilateral advanced arthrosis; previous surgery at the lower limbs or other disease that could influence the gait pattern. With these criteria a group of 7 males and 2 females, mean age 67,7 years old, participated at the study (after a known consensus). All subjects had clinical evaluation. For the dynamic analysis The knee society evaluation system for arthroplasty was used. The knee stability was evaluated on the frontal and mediolateralaxis. For evaluating the pain entity we used the V.A.S. score at rest and during gait, before and after taking the analgesic drug. In addition standard X-ray of the knees were evaluated. Gait Analysis was performed at the biomechanical laboratory “Let people move” of Perugia (Italy). Subjects walked on a track of 12,5 m., a 3Dcinematic evaluation was performed using the APAS system (ARIEL Dynamics, USA) with 4 high speed video cameras. 15 auto reflexed markers were applied on both lower limbs. The ground reaction forces during the gait were recorded at 500 Hz with Bertec platform placed at the centre of there cording area. At the subjects was asked to make 10 valid trials (5 for right and 5 for left knee). During gait was evaluated the range of motion of ankle and foot too. The mean score obtained with the V.A.S. score for the pain during the first section was 3.3 (range 0–7). After taking the analgesic drug and 20 minutes of rest the range was 0–4 at the sequent trial. The results so obtained said that there’s no difference between the range of motion of the knee after taking the drug on the sagittal plane. In addition, no difference neither between the range of motion of the hip and the ankle, on the sagittal plane after the drug. The mean score obtained with the V.A.S. score for the pain during the first section was 3.3 (range 0–7). After taking the analgesic drug and 20 minutes of rest the range was 0–4 at the sequent trial. The results so obtained said that there’s no difference between the range of motion of the knee after taking the drug on the sagittal plane. In addition, no difference neither between the range of motion of the hip and the ankle, on the sagittal plane after the drug

Ankle arthrodesis for isolated ankle arthritis has a high patient satisfaction level; however, gait analysis and functional outcome measurements demonstrate substantial disability. The high patient satisfaction may reflect the extent of disability present prior to the intervention. This study demonstrates that the presence of subtalar or talonavicular arthritis and/or limited motion is a negative predictor for a satisfactory outcome. The risk of developing arthritis of these joints increases with time and therefore the patient can expect a deterioration of their initial result. Ankle arthrodesis should be considered a salvage procedure. Viable alternatives that preserve motion should continue to be explored. The purpose of this study was to utilize gait analysis and validated outcome measures to assess the results of an ankle arthrodesis and compare these results to a healthy age – sex matched control group. Isolated Ankle arthrodesis has a high patient satisfaction rate; however, gait analysis and functional outcome scores demonstrate a significant difference when compared to controls. The presence of limited subtalar and midfoot motion and/or arthritis correlates with a poor clinical result. This study will help the clinician predict outcomes and better educate patients as to the expected results following ankle arthrodesis. Twenty-six patients with an isolated ankle arthrodesis underwent gait analysis and functional outcome assessment using AOFAS ankle-hindfoot scale, MODEMS (includes SF-36) and Ankle Osteoarthritis Scale (AOS). A radiographic analysis was preformed. Mean follow-up was 3.7 years. Results were compared to a group of twenty-six controls. Seventy-seven percent were satisfied and eighty-eight percent would recommend it to a friend. These perceived outcomes did not correlate well with their average Functional Outcome scores and gait analysis. The AOFAS score rated 46% as excellent or good. The MODEMS identified significant differences in Physical Function, Role-Physical and Physical Composite means when compared to controls. The AOS identified significant differences in Pain and Disability means. Gait analysis demonstrated significant differences in stride length, cadence, hip flexion, hindfoot flexion, hindfoot inversion and midfoot flexion. Decreased hindfoot and midfoot motion correlated with poorer outcome scores. Poor radiographic scores correlated with decreased hindfoot/midfoot motion and poorer clinical outcomes. Ankle arthrodesis should be considered a salvage procedure. Viable alternatives that preserve ankle motion should continue to be explored

BACKGROUND. Many patients who underwent a THA, report a feeling of more “physiological” hip and of faster recovery when bigger heads are used. The aim of this study is to evaluate the walking recovery of patients after THA with different head diameters by the means of gait analysis. MATERIALS AND METHODS. A prospective, randomized, blind study was conducted on 60 patients operated by THA at our Institution. Inclusion criteria were: primary hip arthritis, women, age between 55 and 70 years. Exclusion criteria were: other problems influencing walking ability (previous operations of the lower limbs, spine disorders, knee or controlateral hip arthritis). The same uncemented stem, same uncemented press-fit cup, same surgical technique and approach (posterolateral), same surgeons, same postoperative protocol and rehabilitation were employed. The only difference was the head diameter. The patients were randomized into three groups, of twenty patients each one (28mm Cer-on-XPE, 36mm Cer-on-XPE, >42mm Met-on-Met). The gait evaluation have been performed at three temporal steps: preoperatively, two months postoperatively and four months postoperatively. Kinematic parameters were acquired with Elite opto-electronic system (BTS, Milan, Italy) equipped with 6 cameras at 100 Hz frame rate. The system is integrated with a force platform (Kistler, CH) and a synchronic video system using two cameras (BTS, Milan, Italy). Data acquisition and processing were carried out using passive markers positioned according to Davis protocol. At least ten trials for each session were collected in order to assess the repeatability of the results. Gait analysis included kinematic parameters (temporal-spatial parameters and joint angular values) and kinetic parameters (ground interaction forces during walking). Articular moments and powers were computed on the basis of data obtained from dynamometric platform along with those given by kinematic analysis. All patients were compared to a control group. Wilcoxon signed rank test was employed for statistical evaluation. RESULTS. At a preliminary evaluation (still in progress) and statistical analysis, temporal-spatial parameters show no significant differences among the three groups. All the variables of step length, stride length, cadence and velocity show statistical significant improvements towards the standard values, in the four months follow-up in all the groups, and the improvement does not depend on the side operated. CONCLUSIONS. The preliminary evaluation of this study shows that there is no statistical significant difference in standard gait analysis parameters in patients with different head diameters (28mm, 36mm, >42mm) after THA

Purpose of the study: How does a total knee arthroplasty (TKA) function? Do all prostheses provide the excellent results reported in the literature? This gait analysis compared patients with a TKA versus normal subjects in order to obtain a 3D quantification of the kinematic and dynamic differences between patients with a very good functional result and controls. Material and methods: Twenty patients who had a TKA for less than one year and whose functional outcome was scored very good (KSS knee > 85/100, VAS ≤1/10) were compared in a double blind study with 20 normal controls. The knees were masked so that the investigators were unaware of the type of subject (operated or not), the side operated, or the type of implant. The analysis as performed on an AMTI platform with six infrared cameras which followed the displacements of 36 reflectors. Motion Analysis software was applied. The gait parameters recorded were: speed, step length, flexion angle, duration of weight bearing/oscillation phases, and dynamic variables: flexion-extension moment, varus-valgus moment, internal/external rotation moment. Results: Adjusted for age and height, step length, walking speed, and duration of the weight bearing phase were identical in the operated and control populations. Kinematic and dynamic variables demonstrated significant differences. At lift-off, all of the TKA subjects were in functional permanent flexion (m=10); the flexion moment of the quadriceps was less than in the non-operated subjects. In the frontal plane, the weight-bearing phase was identical between the operated subjects and controls, but with a varus dynamic (m=4) during the oscillating phase. In the horizontal plane, there was an external rotation of the tibia (m=+5) during weight bearing. Discussion: Gait analysis provides quantitative information which is not perceptible at physical examination nor with videoscopic explorations. Even patients with an excellent KSS score exhibit important anomalies despite the fact that the physical exam finds a normal range of motion and normal muscle force. The degree by degree 3D gait analysis reveals the difference. Conclusion: Despite a clinical score considered to be very good, patients with a TKA have a functional deficit of the extensor system during take-off, even when the knee has complete active extension; the weight-bearing phase of the step is in external rotation and the oscillating phase exhibits varus laxity