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Purpose To determine the relationships among calf muscle function, tendon length and gait biomechanics in patients surgically treated for chronic Achilles tendon rupture. Methods Twenty-one patients with chronic Achilles tendon rupture (mean age 62 ± 13 years) were evaluated by heel-rise endurance test, Achilles Tendon Resting Angle (ATRA), ultrasound measurement of tendon length and three-dimensional gait analysis. A bivariate two-sided correlation test was performed on all variables in all patients. Results Better performance across all parameters of the heel-rise endurance test correlated with faster walking speed (r = 0.52–0.55), greater peak ankle power (r = 0.56–0.64), shorter stance phase (r = −0.52 to −0.76) and less peak ankle dorsiflexion angle (r = −0.49 to −0.64) during gait. Greater ATRA correlated with longer stance time (r = 0.47), greater peak ankle dorsiflexion angle (r = 0.48), less heel-rise repetitions (r = −0.52) and less heel-rise total work LSI (r = −0.44 to −0.59). Conclusion Greater calf muscle endurance, especially heel-rise total work, is moderately correlated (r = 0.49–0.76) to better ankle biomechanics during gait in patients surgically treated for CATR. The heel-rise endurance test may be a clinical proxy for power development in the ankle joint during gait. Level of evidence IV.

Background: The uncemented collum femoris-preserving (CFP) stem offers preservation of the femoral neck and a more conservative soft tissue resection, which may facilitate a more normal walking pattern. We used gait analysis to evaluate if patients operated with a CFP stem showed more favourable hip kinematics and kinetics when compared with a group of patients operated with a conventional uncemented stem. Methods: 44 patients randomised to receive either a CFP or a Corail stem were studied and were operated using a direct lateral incision. Gait analysis was performed 2 years after the operation with a 12-camera motion capture system and 2 force plates. Hip kinematics and kinetics were analysed and 66 subjects served as controls. Results: None of the variables: speed, stride, cadence and stance showed any statistical significant difference between the 2 study groups. Neither did the hip kinematics and kinetics. Compared to controls, patients operated with the CFP stem showed an increased stance (62.5% vs. 61.1%, p < 0.006) and decreased hip abduction (−2.1° vs. −6.5°). Patients operated with the Corail stem showed decreased speed (1.18 vs. 1.23 m/second), and stride length (1.26 vs. 1.33 m), decreased hip extension (−7.5° vs. −12.8°) and range of hip flexion/extension (38° vs. 40.9°), as well as their hip adduction that was increased (6.3° vs. 4°), whereas their hip abduction was reduced (−2.8° vs. −6.5°), ( p < 0.004) compared to the controls. Conclusions: Use of a CFP stem did not significantly influence any of the gait parameters studied when compared to a standard stem, but still both stems studied were associated with gait deviations when compared to controls. Whether these differences could be attributed to the stem used, the underlying hip disease, or both is still unknown.

Bone-anchored attachment of amputation limb prostheses is increasingly becoming a clinically accepted alternative to conventional socket suspension. The direct transfer of loads demands that the percutaneous implant system and the residual bone withstand all forces and moments transferred from the prosthesis. This study presents load measurements recorded at the bone-anchored attachment in 20 individuals with unilateral transfemoral amputation performing the everyday ambulatory activities: level ground walking, stairs ascent/descent and slope ascent/descent. Mean peak values for the sample populations across activities ranged from 498–684 N for the resultant force, 26.5–39.8 Nm for the bending moment, and 3.1–5.5 Nm for the longitudinal moment. Significant differences with respect to level walking were found for the resultant force during stairs ascent, (higher, p = 0.002), and stairs descent, (lower, p = 0.005). Using a crutch reduced the peak resultant forces and the peak bending moments with averages ranging from 5.5–12.6 % and 13.2–15.6 %, respectively. Large inter-participant variations were observed and no single activity resulted in consistently higher loading of the bone-anchored attachment across the participants. Results from this study can guide future development of percutaneous osseointegrated implant systems for limb prostheses and their rehabilitation protocols.

Introduction Tibial plateau fractures involve the knee joint, one of the most weight-bearing joints in the body. Studies have shown that gait asymmetries exist several years after injury. Instrumental gait analysis, generating both kinematic and kinetic data from patients with tibial plateau fractures, is uncommon. Aim To examine walking ability and knee range of motion in patients suffering intra-articular tibial plateau fractures. Method Twenty participants, eight males and 12 females, aged 44 years (range 26–60), with unilateral isolated tibial plateau fractures, were examined 12 weeks (range 7–20) after injury. The investigation consisted of passive range of motion (ROM) using a goniometer, six-minute walking test (6 MW), pain estimation using the visual analogue scale (VAS), the “Knee injury and Osteoarthritis Outcome Score” (KOOS) self-assessment questionnaire and instrumental 3-dimensional gait analysis (3DGA). 3DGA included spatiotemporal variables (speed, relative stance time, step length), kinematic variables (knee flexion, knee extension, ankle dorsiflexion) and kinetic variables (generating knee power (extension) and ankle power (plantarflexion)). A skin marker model with twenty reflective markers was used. Non-parametric tests were used for comparisons of the injured leg, the uninjured leg and a reference group. Result The participants walked more slowly compared with healthy references (p p p = 0.001). The maximum knee extension in the single stance phase was worse in the injured side compared with the uninjured side and the reference group (p p p p p p p Conclusion Patients who have sustained tibial plateau fractures generally display a limitation in their walking pattern 3 months after injury. These limitations are mainly related to the inability to extend the knee.

Objectives: In this single-subject experimental design study, we investigated the effect of late-phase stroke rehabilitation on gait pattern. Methods: A subgroup from a previous clinical study, four men in the chronic phase after stroke, received 3 weeks of enriched and task-specific therapy (ETT) consisting of task-specific exercise, socialization, sensory and cognitive stimulation in a Mediterranean climate. Spatiotemporal gait variables, kinematics and symmetry were measured before and after the intervention in an advanced gait laboratory. Statistical significance was determined with the two-standard deviation band method. Results: Subject 1 had kinematic improvements (increased knee flexion during swing and dorsiflexion during stance) and spatiotemporal gains (increased speed, double-limb support, stride length and cadence) after ETT. Subject 2 had improved swing time symmetry ratio but no spatiotemporal or kinematic improvements. Subject 3 had gains in speed, stride width and length, and knee flexion during swing. Subject 4 had a change in cadence but no gain in kinematics, nor symmetry. Conclusions: Two of the four participants had significant improvements in gait kinematics, symmetry, and spatiotemporal variables after the intervention. Future research should consider the potential effects of ETT with the aim of validating the conclusions that can be drawn from this study.

Gluteus maximus flap transfer (GMT) is a surgical technique used to improve gait kinematics and kinetics, as well as to reduce and ameliorate the functional outcome in patients with hip abductor deficiency following total hip arthroplasty (THA). The purpose of this observational study was to evaluate the gait pre- and postoperatively and examine whether GMT increases the abduction moment. Materials and Methods: A gait analysis based on reflective markers and force plates was performed in 15 patients who underwent GMT and were examined using an optical tracking system before and at a minimum of 13 months after the operation. The median follow-up time was 24 (13–60) months. The primary outcome was hip abduction moment (Nm/kg) during gait. The control group consisted of 15 female subjects without any gait pathology. Results: The mean adduction moment was significantly higher compared with controls before the operation (p = 0.02), but this did not apply to the abduction moment (p = 0.60). At the group level, the abduction moment did not improve postoperatively (p = 0.30). Only six of fifteen patients slightly improved their hip abduction moment postoperatively. However, speed (0.74 to 0.80 m/s) and cadence (94 to 105 steps/min) were improved (p < 0.03). Discussion: The results of this study showed no improvement in the hip abduction moment after GMT surgery. In our experience, abduction deficiency following primary THA is still a difficult and unsolved problem.

The gait pattern in children with cerebral palsy (CP) often differs from normal, with slow velocity, problem with foot clearance and increased stress on joints. Several factors, such as muscle tone, impaired motor control, muscle contractures, skeletal deformities and leg length discrepancy affect gait. Leg length discrepancy can be treated surgically or with elevation of the shoe on the short leg. The purpose of this study was to examine whether compensating for leg length discrepancy, with elevation of the sole, leads to a change in movement pattern during walking in children with spastic CP. Results: Ten children with spastic CP, able to walk without aids, and 10 typically developing (TD) children aged between seven and 14 years were assessed with 3D gait analysis: 1) barefoot, 2) with shoes and 3) with an extra sole beneath the shoe for the shorter leg. All children with CP had a leg length discrepancy of more than or equal to 1.0 cm. In the barefoot condition, the velocity was slower and the stride length was shorter, in children with CP compared with TD. The stride length and gait velocity increased in children with CP with shoes and shoe + sole and the stance time became more symmetrical. Among children with CP, there was more flexion in the longer leg relative to the short leg during barefoot walking. Differences in the kinematic pattern between the long and the short leg decreased with the extra sole.

There is an increasing demand to quantify the footprints, ecological, economic and social, in terms of the effect of different interventions in healthcare. The aim of this study was to compare two systems providing patients with diabetes with insoles in terms of their ecological, economic and social footprints. Prefabricated insoles (PRI) were compared with custom-made insoles (CMI). Using a welfare-economic monetary approach, costs were estimated for (1) treatment, (2) travelling to and from the hospital in terms of both fuel and time consumed by the patients and (3) society through emissions contributing to climate change. The proportion of patients/year that could be supplied within the same budget, for each individual treatment, was calculated. The cost of the insoles was 825 SEK (PRI) and 1450 SEK (CMI), respectively. The cost, mean value/patient due to the consumption of patients’ time at the department, was 754 SEK (PRI) and 1508 SEK (CMI), respectively. Emissions, in terms of CO2 equivalent, were 13.7 (PRI) and 27.4 (CMI), respectively. Using PRI, a total of 928 patients could be provided/year compared with 500 patients if CMI are used. By using PRI, the cost/treatment was reduced by 46%. The cost of treatment dominated and the cost of time consumed by patients were also substantial. The societal cost of contributing to climate change was of low importance. By using PRI, the needs of 86% more patients could be met within the same budget. Using these methods, the contribution of healthcare systems to the 17 Sustainable Development Goals approved by the UN can be quantified.

We simultaneously examined 14 patients with OTS and dynamic radiostereometric analysis (RSA) to evaluate the accuracy of both skin- and a cluster-marker models. The mean differences between the OTS and RSA system in hip flexion, abduction, and rotation varied up to 9.5° for the skin-marker and up to 11.3° for the cluster-marker models, respectively. Both models tended to underestimate the amount of flexion and abduction, but a significant systematic difference between the marker and RSA evaluations could only be established for recordings of hip abduction using cluster markers (p = 0.04). The intra-class correlation coefficient (ICC) was 0.7 or higher during flexion for both models and during abduction using skin markers, but decreased to 0.5-0.6 when abduction motion was studied with cluster markers. During active hip rotation, the two marker models tended to deviate from the RSA recordings in different ways with poor correlations at the end of the motion (ICC ≤0.4). During active hip motions soft tissue displacements occasionally induced considerable differences when compared to skeletal motions. The best correlation between RSA recordings and the skin- and cluster-marker model was found for studies of hip flexion and abduction with the skin-marker model. Studies of hip abduction with use of cluster markers were associated with a constant underestimation of the motion. Recordings of skeletal motions with use of skin or cluster markers during hip rotation were associated with high mean errors amounting up to about 10° at certain positions. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1515-1522, 2017.

Background: According to previous gait analyses, insertion of a total hip arthroplasty (THA) will improve the range of hip flexion-extension but not to normal. Use of short stems could have a potential to improve the motion by preservation of more bone and muscular attachments. We evaluated whether a short femoral stem resulted in improved hip motion compared to a conventional stem in patients who underwent 1-stage bilateral THA. The most painful hip was randomised to either design and the 2nd hip was operated with the design not used on the 1st side. Methods: Gait analysis was performed with an optical tracking system in 22 patients. The follow-up was performed 1 and 2 years after the operation. The mean age was 59 (SD 7.7) years and body mass index was 27.7 (SD 4.3). 66 subjects without hip pathology served as controls. Results: Minimal differences were observed, between or within the 2 different stem designs during gait at the 2 follow-up occasions. Comparison between each of the 2 stem designs and controls at 2 years revealed reduced stride length (p = 0.009), cadence, hip extension (pConclusions: We found no difference in gait parameters between the short and the conventional stem after 1-stage bilateral THA. Although both hip joints were operated at the same time motions and moments did not normalise after bilateral 1-stage operations.

Objectives To examine whether different vertical drop jump (VDJ) landing depth (small versus deep) and stance width (wide versus narrow) may alter movement biomechanics in female recreational athletes. The purpose was also to identify whether leg muscle strength is a predictive factor for knee control during a VDJ. Design Cross-sectional. Setting Biomechanics laboratory. Participants: Eighteen women aged between 18 and 30 years. Main outcome measures Three VDJ tests were used for biomechanical analysis: 1) small “bounce” jump (BJ), 2) deep “countermovement” jump with wide (CMJW) and 3) narrow foot position (CMJN). Subjects also performed an isometric knee-extension strength test, dichotomized to ‘weak’ versus ‘strong’ subjects according to median and quartiles. Results There were greater knee valgus angles during landing for both the CMJW and CMJN test compared to the BJ test (p ≤ 0.05). Differences in knee valgus between weak and strong subjects were significant for the BJ test (p = 0.044) but not for any of the other tests. Conclusions VDJ landing depth influences knee kinematics in women. Landing depth may therefore be considered when screening athletes using the VDJ test. Also, muscle strength seems to influence the amount of knee valgus angles, but the difference was not statistically significant (except for the BJ test) in this small cohort.

Background The gait pattern varies within the population and between patient groups with different musculoskeletal diseases. It also varies over time due to various reasons. Three-dimensional gait analysis (3DGA) is frequently used to measure these changes, but the precision of this methodology may vary. Methods We primarily aimed to study the repeatability of hip motion measurements in patients with unilateral osteoarthritis (OA), patients with unilateral total hip arthroplasty (THA) and healthy controls. A secondary aim was to delineate any differences in hip motion during walking between these groups. Ten males and 10 females in each group were recruited. All patients underwent gait assessments using 3DGA recorded by 2 examiners. Data was analysed with comparison of variance and linear regression. Results The variability of the extension-flexion recordings was smallest in healthy controls (SD

Background: Special insoles and shoes designed to prevent foot ulcers caused by repetitive high pressures are recommended for patients with diabetes who have any of the following risk factors: neuropathy; peripheral vascular disease; foot deformities; previous ulcers; amputation; and skin pathologies. However, there is a need for increased knowledge regarding: a) differences in the peak pressure (PP) and pressure time integral (PTI) for different types of insoles; and b) the properties of the pressure distribution for insoles used over a period of several months. We present the results of a randomized trial to compare the plantar pressures of three commonly used insoles. Objectives: The primary objective was to compare the PP and PTI between three types of insoles. The secondary objective was to explore the long-term pattern of peak plantar pressure distribution and variations in specific regions of interest (ROI). The tertiary objective was to investigate the impacts of insole adjustments, how much the insoles were used, and the levels of patient satisfaction. Methods: In a 2-year trial, 114 patients with type 1 (N = 31) or type 2 (N = 83) diabetes (62 men and 52 women; mean age, 57.7 ± 15.4 years; duration of diabetes, 12.3 ± 11.2 years; neuropathy, 38%), were randomized to be supplied with one of three different insoles. The ethylene vinyl acetate (EVA) insoles were used in outdoor walking shoes. The 35 EVA group (N = 39) received soft custom-made insoles composed of EVA of 35 shore A hardness, the 55 EVA group (N = 37) received custom-made insoles composed of EVA of 55 shore hardness, and the control group (N = 38) received prefabricated insoles composed of a hard core with a top layer of soft 12 shore hardness microfiber. Using F-Scan®, the in-shoe plantar pressures were measured at seven ROI (hallux, metatarsal head 1, metatarsal head 2, metatarsal head 4, metatarsal head 5, lateral aspect of the mid-foot, heel) on five occasions during the study period. The plantar-pressure variables used were PP (main outcome) and PTI. The plantar patterns of load were explored, satisfaction and usage of the insoles were rated by the participants, and insole adjustments were recorded. Results: A mixed model analysis estimated lower PP values in the heel regions for the 35 EVA and 55 EVA insoles (171 ± 13 and 161 ± 13 kPa, respectively) than for the prefabricated insoles (234 ± 10 kPa) (p

Early designs of uncemented hip implants turned out to be failures mainly because the prerequisites for durable implant fixation were unknown. One exception was the chrome–cobalt stem of the Madreporic Lord prosthesis. We prospectively studied this prosthetic design in 107 hips that underwent surgery in 1979–1986. At the last follow-up, five stems and 54 cups had been revised, corresponding to stem and cup survival rates of 92% ± 3% and 45% ± 5% at 26 years. In all, 66 hips with remaining Lord stems were available for clinical follow-up 26 years (24–29) after the index operation. The mean total Harris hip and pain scores were 81 (SD 14) and 41 (SD 5).

We simultaneously examined 14 patients with OTS and dynamic radiostereometric analysis (RSA) to evaluate the accuracy of both skin- and a cluster-marker models. The mean differences between the OTS and RSA system in hip flexion, abduction, and rotation varied up to 9.5° for the skin-marker and up to 11.3° for the cluster-marker models, respectively. Both models tended to underestimate the amount of flexion and abduction, but a significant systematic difference between the marker and RSA evaluations could only be established for recordings of hip abduction using cluster markers (p = 0.04). The intra-class correlation coefficient (ICC) was 0.7 or higher during flexion for both models and during abduction using skin markers, but decreased to 0.5-0.6 when abduction motion was studied with cluster markers. During active hip rotation, the two marker models tended to deviate from the RSA recordings in different ways with poor correlations at the end of the motion (ICC ≤0.4). During active hip motions soft tissue displacements occasionally induced considerable differences when compared to skeletal motions. The best correlation between RSA recordings and the skin- and cluster-marker model was found for studies of hip flexion and abduction with the skin-marker model. Studies of hip abduction with use of cluster markers were associated with a constant underestimation of the motion. Recordings of skeletal motions with use of skin or cluster markers during hip rotation were associated with high mean errors amounting up to about 10° at certain positions. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1515-1522, 2017.

This study describes the changes in hip and pelvic kinematics in 19 trans-femoral amputees, who were treated with an osseointegrated trans-femoral prosthesis. Patients were studied with 3-dimensional gait analysis, walking with socket prosthesis within two days before the osseointergration procedure. The post-operative gait analysis was carried out at the 2 year follow-up visit. Fifty-seven; age-, side- and gender-matched healthy subjects served as controls. Post-operative data showed that patients who had an osseointegrated transfemoral prosthesis increased their hip extension by 7.3° (p=0.007), changing from -2.6° (range -13.4° to 10.7°) to -9.9° (range -29.4° to 5°). Moreover, the pre-operative anterior pelvic tilt was reduced by 4.0° (p=0.016), changing from 21.7° (range 11.9-34.8°) to 17.7° (range 5.5-25.7°). Values for hip extension and pelvic tilt changed toward those of controls. These results confirm that patients treated with osseointegrated trans-femoral prosthesis encounter significant changes of their kinematic pattern in terms of hip extension and anterior pelvic tilt. Even though the changes were moderate they may, in the long-term have a positive influence on low-back biomechanics and could contribute to reducing the risk of further problems with low back pain.

Background and Purpose. The physiological cost index (PCI) is a clinical measurement used to estimate the energy cost of walking. The reproducibility of the PCI has been questioned and no study has investigated the measurement error among individuals with a lower-limb amputation. The aim was to investigate the test–retest reproducibility of the PCI in individuals with a lower-limb amputation and healthy adults. Methods. The study comprised 28 individuals (20 males, eight females, mean age 49 years) with a unilateral amputation due to reasons other than vascular disease and 31 healthy volunteers (20 males, 11 females, mean age 47 years). PCI values were obtained by registering heart rate at rest and during level indoor walking for 5 minutes at a comfortable speed. A within-day test–retest assessment was performed. Reproducibility analyses included intra-class correlation, analyses of systematic differences between measurements, calculation of the smallest detectable change (SDC) and coefficient of variation (CV), and the results were finally visualized using Bland–Altman plots. Results. The reliability in terms of intra-class correlation was excellent for both groups (0.966 and 0.948). In the amputee group, the PCI revealed a mean difference of 0.026 (p = 0.016) between tests (PCI = 0.555, standard deviation [SD] = 0.214 and PCI = 0.581, SD = 0.236, respectively). In the healthy group, there was no systematic difference between tests (PCI = 0.329, SD = 0.114 and PCI = 0.331, SD = 0.110, respectively). The SDC was 0.116 in the amputee group and 0.070 in the healthy group, giving a CV of 20.4% and 21.0%,respectively. Conclusions. The within-day test–retest reproducibility of the PCI was excellent among individuals with lower-limb amputations and healthy adults in terms of intra-class correlation and acceptable in terms of agreement. The SDC, which was calculated for each group, should be considered when demonstrating an individual difference after an intervention. Copyright © 2010 John Wiley & Sons, Ltd.

Objective : Foot deformities, neuropathy, and dysfunction in the lower extremities are known risk factors that increase plantar peak pressure (PP) and, as a result, the risk of developing foot ulcers in patients with diabetes. However, knowledge about the prevalence of these factors is still limited. The aim of the present study was to describe the prevalence of risk factors observed in patients with diabetes without foot ulcers and to explore possible connections between the risk factors and high plantar pressure. Patients and methods : Patients diagnosed with type 1 ( n= 27) or type 2 ( n= 47) diabetes (mean age 60.0±15.0 years) were included in this cross-sectional study. Assessments included the registration of foot deformities; test of gross function at the hip, knee, and ankle joints; a stratification of the risk of developing foot ulcers according to the Swedish National Diabetes Register; a walking test; and self-reported questionnaires including the SF-36 health survey. In-shoe PP was measured in seven regions of interests on the sole of the foot using F-Scan ® . An exploratory analysis of the association of risk factors with PP was performed. Results : Neuropathy was present in 28 (38%), and 39 (53%) had callosities in the heel region. Low forefoot arch was present in 57 (77%). Gait-related parameters, such as the ability to walk on the forefoot or heel, were normal in all patients. Eighty percent had normal function at the hip and ankle joints. Gait velocity was 1.2±0.2 m/s. All patients were stratified to risk group 3. Hallux valgus and hallux rigidus were associated with an increase in the PP in the medial forefoot. A higher body mass index (BMI) was found to increase the PP at metatarsal heads 4 and 5. Pes planus was associated with a decrease in PP at metatarsal head 1. Neuropathy did not have a high association with PP. Conclusions : This study identified several potential risk factors for the onset of diabetic foot ulcers (DFU). Hallux valgus and hallux rigidus appeared to increase the PP under the medial forefoot and a high BMI appeared to increase the PP under the lateral forefoot. There is a need to construct a simple, valid, and reliable assessment routine to detect potential risk factors for the onset of DFU. Keywords : diabetic foot; foot deformities; neuropathy; prevention; foot anthropometrics; plantar pressure; risk factors (Published: 17 June 2015) Citation: Diabetic Foot & Ankle 2015, 6: 27593 - http://dx.doi.org/10.3402/dfa.v6.27593

This study aimed to examine the effects of two different load carriage systems on gait kinematics, temporospatial gait parameters and self-reported comfort in Swedish police.21 active duty police officers were recruited for this crossover study design. Biomechanical and self-report data was collected on two testing occasions. On occasion 1, three dimensional kinematic data was collected while police wore a/no equipment (control), b/their standard issues belt and ballistic protection vest and c/a load bearing vest with ballistic protection vest. Police then wore the load bearing vest for a minimum of 3 months before the second testing occasion.The load bearing vest was associated with a significant reduction in range of motion of the trunk, pelvis and hip joints. Biomechanical changes associated with the load bearing vest appeared to reduce with increased wear time. In both the standard issue belt condition and the load bearing vest condition, police walked with the arms held in a significantly greater degree of abduction. Self-report data indicated a preference for the load bearing vest.The two load carriage designs tested in this study were found to significantly alter gait kinematics. The load bearing vest design was associated with the greatest number of kinematic compensations however these reduced over time as police became more accustomed to the design. Results from this study do not support selection of one load carriage design over the other and providing individuals with the option to choose a load carriage design is considered appropriate.

Previous radiostereometric studies have revealed abnormal anterior-posterior translation of the femur in patients operated with AMK (DePuy, Johnson and Johnson, Leeds, UK) total knee arthroplasty (TKA). Based on these observations, we hypothesized that patients with TKA have an abnormal gait pattern, and that there are differences in kinematics depending on the design of the tibial joint area.We used a gait analysis system to evaluate the influence of joint area design on the kinematics of the hip and knee during level walking. 39 TKA patients (42 knees) and 18 healthy age-matched controls were studied. Patients with 5 degrees varus/valgus alignment or less were randomized to receive either a relatively flat or a concave tibial insert with retention of the posterior cruciate ligament. Patients who had more than 5 degrees varus-valgus alignment and/or extension defect of 10 degrees or more were randomized to receive the concave or a posterior-stabilized tibial component with resection of the posterior cruciate ligament.Patients with TKA tended to have less hip and knee extension and decreased knee and hip extension moment than controls. They also tended to walk more slowly. TKA altered the gait pattern, but choice of implant design had little influence.In patients with a similar degree of degenerative joint disease and within the limits of the constraints offered by the prostheses under study, the choice of joint area constraint has little influence on the gait pattern.

The Swedish National Total Hip Arthroplasty Register records primary hip replacements, revisions and surgical technique/environmental factors. The end-point for failure is revision. A prosthesis still in place, however, does not mean success. Clinical and radiographic outcomes should describe in more detail the efficacy of hip replacement surgery instead of the relatively blunt outcome measure that the register can provide. We performed a clinical outcome analysis on patients with primary total hip replacement thus testing the adequacy of the end-point for failure in the Swedish register. 1,113 randomly selected patients who had had total hip replacement surgery between 1986 and 1995 answered a disease-specific self-administered questionnaire (WOMAC). A cohort of 344 patients was studied, using the Harris Hip Score and a conventional radiographic examination as outcome measures. We found clinical failure rates of 13% and 20% for all implants after 10 years, using 60 points or revision as the definition of failure in the Harris Hip Score and WOMAC, respectively. The result, according to the register during the same period, was a 7% revision rate. The clinical failure rate depended on the type of evaluation tool, definition of failure and demographics, which made it difficult to decide whether there was a need for revision. With the exception of pain measured by the Harris Hip Score, the results showed no significant correlation between clinical failure and radiographic failure. Hence, with the knowledge that there is a difference between the revision rate according to the register and clinical outcome, the strict definition of failure in the register is useful as an end-point for primary hip replacement surgery.

Quantitative gait analysis is a powerful tool for the assessment of a number of physical and cognitive conditions. Unfortunately, the costs involved in providing in-lab 3D kinematic analysis to all patients is prohibitive. Inertial sensors such as accelerometers and gyroscopes may complement in-lab analysis by providing cheaper gait analysis systems that can be deployed anywhere. The present study investigates the use of inertial sensors to quantify gait symmetry and gait normality. The system was evaluated in-lab, against 3D kinematic measurements; and also in-situ, against clinical assessments of hip-replacement patients. Results show that the system not only correlates well with kinematic measurements but it also corroborates various quantitative and qualitative measures of recovery and health status of hip-replacement patients AccelGait

Early designs of uncemented hip implants turned out to be failures mainly because the prerequisites for durable implant fixation were unknown. One exception was the chrome-cobalt stem of the Madreporic Lord prosthesis. We prospectively studied this prosthetic design in 107 hips that underwent surgery in 1979-1986. At the last follow-up, five stems and 54 cups had been revised, corresponding to stem and cup survival rates of 92%±3% and 45%±5% at 26years. In all, 66 hips with remaining Lord stems were available for clinical follow-up 26years (24-29) after the index operation. The mean total Harris hip and pain scores were 81 (SD 14) and 41 (SD 5).

Background and purpose Invasive methods are more reproducible and accurate than non-invasive ones when it comes to recording knee kinematics, but they are usually less accessible and less safe, mainly due to risk of infection. For this reason, non-invasive methods with passive markers are widely used. With these methods, varying marker sets based on a number of single markers, or sets of markers, known as clusters, are used to track body segments. We compared one invasive method—radiostereometric analysis—with a non-invasive method, an optical tracking system with 15 skin-mounted markers. Methods 9 subjects (10 knees) were investigated simultaneously with a dynamic RSA system and a motion-capture system while performing an active knee extension. Results For flexion/extension, there was good agreement on an individual basis and at the group level. For internal/external rotation, the group mean was fairly similar, up to 25 degrees of flexion. Recordings of abductions and/or adductions revealed a systematic mean difference of 2–4 degrees during the range of flexion measured. The correlation between the 2 methods in the horizontal and frontal planes was poor. Interpretation Our skin-marker model provided reliable data for flexion/extension. Recordings of internal/external rotation and abduction/adduction were less accurate on an individual basis than at the group level, most probably due to soft-tissue motion and the presence of small true motion in these planes.

The physiological cost index (PCI) is a clinical measurement used to estimate the energy cost of walking. The reproducibility of the PCI has been questioned and no study has investigated the measurement error among individuals with a lower-limb amputation. The aim was to investigate the test-retest reproducibility of the PCI in individuals with a lower-limb amputation and healthy adults.The study comprised 28 individuals (20 males, eight females, mean age 49 years) with a unilateral amputation due to reasons other than vascular disease and 31 healthy volunteers (20 males, 11 females, mean age 47 years). PCI values were obtained by registering heart rate at rest and during level indoor walking for 5 minutes at a comfortable speed. A within-day test-retest assessment was performed. Reproducibility analyses included intra-class correlation, analyses of systematic differences between measurements, calculation of the smallest detectable change (SDC) and coefficient of variation (CV), and the results were finally visualized using Bland-Altman plots.The reliability in terms of intra-class correlation was excellent for both groups (0.966 and 0.948). In the amputee group, the PCI revealed a mean difference of 0.026 (p = 0.016) between tests (PCI = 0.555, standard deviation [SD] = 0.214 and PCI = 0.581, SD = 0.236, respectively). In the healthy group, there was no systematic difference between tests (PCI = 0.329, SD = 0.114 and PCI = 0.331, SD = 0.110, respectively). The SDC was 0.116 in the amputee group and 0.070 in the healthy group, giving a CV of 20.4% and 21.0%,respectively.The within-day test-retest reproducibility of the PCI was excellent among individuals with lower-limb amputations and healthy adults in terms of intra-class correlation and acceptable in terms of agreement. The SDC, which was calculated for each group, should be considered when demonstrating an individual difference after an intervention.

The aim of the study was to investigate the influence of muscle strength training on gait outcomes in children with cerebral palsy. Sixteen children (two females, 14 males, Gross Motor Function Classification System levels I-II, mean age 12y 6mo, range 9y 4mo-15y 4mo) underwent muscle strength measurement using a handheld device, Gross Motor Function Measure (GMFM) assessment, three-dimensional gait analysis, joint range of motion assessment, and grading of spasticity before and after 8 weeks of training. All participants had a diagnosis of spastic diplegia and could walk without aids. Training consisted of exercises for lower extremity muscles with free weights, rubber bands, and body weight for resistance, three times a week. Values for muscle strength below normal were identified in all children; this was most pronounced at the ankle, followed by the hip muscles. After training, muscle strength and GMFM scores increased, velocity was unchanged, stride length increased, and cadence was reduced. There was an increase in hip extensor moment and power generated at push off. Eight weeks of muscle strength training can increase muscle strength and improve gait function.

There are various types of pain: acute, inflammatory, and neuropathic. The latter starts with a nerve injury, which could be secondary to an inflammatory reaction. Neuropathic pain often remains even after the original injury has healed and sometimes becomes chronic. It has recently been proposed that activated astrocytes and microglial cells could be the generators maintaining neuropathic pain. As astrocytes exhibit gap junction coupled networks, glia may be involved in spreading of pain sensations in form of Ca2+ oscillations or waves. Astrocytic Ca2+ oscillations induce ATP release which in turn stimulates both microglial cells and those monocytes that have crossed the blood-brain barrier, and also stimulates distant astrocyte networks and microglial cells. These activated cells release pro-inflammatory cytokines. One theory is that the Ca2+ oscillations by their induction and release of growth factors, give rise to new synapses, thereby establishing new neuronal contacts for maintaining and spreading pain sensation.

A gait analysis system was used to evaluate the kinematics of the hip and knee during stair ascending and descending after operation with total knee replacement. Patients with 5 degrees varus/valgus alignment or less were selected randomly to receive either a flat or a concave tibial component with retention of the posterior cruciate ligament. Patients who had more than 5 degrees varus/valgus alignment and/or an extension defect of 10 degrees or more were selected randomly to receive the concave or posterior-stabilized tibial component with resection of the posterior cruciate ligament. Twenty patients and 17 controls were studied 1-2 years after the operation. Patients had abnormal kinematics during stair ascending and descend-ing. Both knee extension and flexion were reduced. Hip extension tended to decrease, and decreased hip extension moment was noted.

Background. There are few previous studies of sit-to-stand movement following total knee arthroplasty. Aim of the study was to test the hypotheses that total knee replacement alters the maximum trunk, hip, knee and ankle flexion–extension movements during chair rising, and that the design of the tibial plateau has small influence on the kinematics. Methods. A motion analysis system was used to evaluate kinematics of the trunk, hip, knee and ankle when rising from one chair and sitting down on another. Patients with 5° varus/valgus alignment or less received either a flat or a concave tibial insert with retention of the posterior cruciate ligament. Patients who had more malalignment and /or extension defect of 10° or more were randomized to receive the concave or a posterior-stabilized tibial component with resection of the posterior cruciate ligament. The two groups of patients operated with and without resection of the posterior cruciate ligament were analysed separately and compared with a control group. 28 patients (29 knees) and 16 controls were in the final analysis. Findings. Decreased hip and knee extension compared to the controls was seen, but there were no statistically significant differences in kinematics between the designs. Interpretation. Choice of implant design in total knee arthroplasty had no detectable effects on kinematics of hip and knee joints during sit-to-stand movement.