Background: It is unknown whether the height of a heel-rise performed in the single-leg standing heel-rise test 1 year after an Achilles tendon rupture (ATR) correlates with ankle biomechanics during walking, jogging, and jumping in the long-term.

Purpose: To explore the differences in ankle biomechanics, tendon length, calf muscle recovery, and patient-reported outcomes at a mean of 6 years after ATR between 2 groups that, at 1-year follow-up, had less than 15% versus greater than 30% differences in heel-rise height.

Methods: Seventeen patients with less than 15% (<15% group) and 17 patients with greater than 30% (>30% group) side-toside difference in heel-rise height at 1 year after ATR were evaluated at a mean (SD) 6.1 (2.0) years after their ATR. Ankle kinematics and kinetics were sampled via standard motion capture procedures during walking, jogging, and jumping. Patient-reported outcome was evaluated with Achilles tendon Total Rupture Score (ATRS), Physical Activity Scale (PAS), and Foot and Ankle Outcome Score (FAOS). Tendon length was evaluated by ultrasonography. The Limb Symmetry Index (LSI = [Injured Side divided by Healthy Side x 3 100) was calculated for side differences.

Results: The.30% group had significantly more deficits in ankle kinetics during all activities compared with patients in the <15% group at a mean of 6 years after ATR (LSI, 70%-149% and 84%-106%, respectively; P =.010-.024). The.30% group, compared with the <5% group, also had significantly lower values in heel-rise height (LSI, 72% and 95%, respectively; P<. 001) and heel-rise work (LSI, 58% and 91%, respectively; P<. 001) and significantly larger side-to-side difference in tendon length (114% and 106%, respectively; P =.012). Achilles tendon length correlated with ankle kinematic variables (r = 0.38-0.44; P =.015-.027) whereas heel-rise work correlated with kinetic variables (r = 20.57 to 0.56; P =.001-.047). LSI tendon length correlated negatively with LSI heel-rise height (r = 20.41; P =.018). No differences were found between groups in patient-reported outcome (P =.143-.852).

Conclusion: Height obtained during the single-leg standing heel-rise test performed 1 year after ATR related to the long-term ability to regain normal ankle biomechanics. Minimizing tendon elongation and regaining heel-rise height may be important for the long-term recovery of ankle biomechanics, particularly during more demanding activities such as jumping.

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. 

Background: The literature offers sparse information about foot anthropometrics in patients with diabetes related to foot length, foot width and toe height, although these measurements are important in shoe fitting. A poorly fitted shoe is one of many contributory factors in the development of diabetic foot ulcers. The purpose of this study was to describe the foot anthropometrics in groups of patients with diabetes, in groups representing the general population and to explore whether foot anthropometrics differ between patients with diabetes and the general population.

Method: Foot anthropometrics (foot length, foot width and maximum toe height) was measured in 164 patients with diabetes, with and without neuropathy (n = 102 and n = 62 respectively). The general population was represented by 855 participants from two sources.

Results: Foot length, foot width and toe height varied (220-305 mm; 82-132 mm and 15-45 mm respectively) in the diabetic group and in the group representing the general population (194-306 mm; 74-121 mm and 17-31 mm respectively). Age, gender and BMI influence the foot anthropometrics, however, when adjusting for theses variables the index foot length/width was lower (2.58) in patients with diabetes without neuropathy vs. controls (2.63), p = 0.018. Moreover, patients with diabetes with neuropathy had wider feet (98.6 mm) compared with the controls (97.0 mm), p = 0.047.

Conclusions: The individual variations of foot length, foot width and maximum toe height were large. The impact of gender on foot anthropometrics was confirmed and the impact of age and BMI were shown. Patients with diabetes seemed to have a wider forefoot width and a lower foot length to foot width ratio compared to the controls.

Background: The prevention and care of foot problems in diabetes begins with a risk classification. Today, the prosthetists and orthotists (CPO) and other health care professionals assess the risk of developing foot ulcers more or less subjectively. The objective of the study was to describe the construction of an eHealth tool, the D-Foot, which generates a risk classification. The reliability of the D-Foot was tested.

Methods: The D-Foot includes 22 clinical assessments and four self-reported questions. The content validity was assured by expert group consensus and the reliability was assessed through an empirical test-retest study. Inter- and intra-rater reliability was calculated using patients referred to four departments of prosthetics and orthotics (DPO).

Results: The agreement for the risk classification generated using the D-Foot was 0.82 (pooled kappa 0.31, varying from 0.16 to 1.00 at single DPOs). The inter-rater agreement was > 0.80 regarding the assessments of amputation, Charcot deformity, foot ulcer, gait deviation, hallux valgus/hallux varus and risk grade. The inter- and intra-rater agreements for the discrete measurements were > 0.59 and > 0.72 respectively. For continuous measurements, the inter- and intra-rater correlation varied (0.33-0.98 and 0.25-0.99 respectively).

Conclusion: The D-Foot gave a reliable risk foot classification. However, there was a variation in the inter- and intra-rater reliability of the assessments included and refinements are needed for variables with low agreement. Based on the results, the D-Foot will be revised before it is implemented in clinical practice.

Background

Special insoles and shoes designed to prevent foot ulcerscaused 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 < 0.001). Also for some of the other six ROI indications of difference in PP or PTI could be observed. The redistribution of peak plantar pressure for all of the insoles, was stable at the mid-foot, while the proportion of load on the distal area changed during the study period According to the self-reported answers (scale, 0–100), the average usage of the insoles was rated as 79 and satisfaction was rated as 85 (N = 75). Thirty-two percent of the subjects had not received foot care. Fourteen adjustments to insoles were made during the study period, and 86 pairs of insoles were exchanged due to wear, with 49% being exchanged in the 35 EVA group.

Conclusions

Custom-made insoles used in combination with stable walking shoes gave lower pressures at the heel region. The variation makes it difficult to detect a systematic difference in plantar pressure for the 6 ROI, if such a difference indeed exists. The levels of satisfaction and usage for all the insoles tested were high. The insoles maintained their pressure redistribution properties over long periods, and few adjustments were needed.

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 (R). 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.

Background: Therapeutic shoes can prevent diabetic foot reulcerations but their use is complicated by the fact that shoes have psychological and social meanings, which is believed to put a larger burden on women than men. The aim was to compare attitudes and attributes of women and men using therapeutic shoes for diabetic foot complications.

Methods: A questionnaire was posted to 1230 people with diabetes who had been fitted with therapeutic shoes. Women's and men's answers were compared using t-tests, Mann-Whitney U tests and chi-square tests with Fischer's exact tests. P-values < 0.05 were considered statistically significant.

Results: Questionnaires from 443 (36.0%) respondents (294 men, 149 women, mean age 69.2 years) were analyzed. More men than women (p < 0.05) had paid employment (20.4% vs 9.4%), had someone who reminded them to wear their therapeutic shoes (27.6% vs 10.0%), and had a history of foot ulcers (62.9% vs 46.3%) or minor amputation (17.7% vs 6.7%). More women than men received disability pension (18.8% vs 10.2%). Women reported worse general health, lower internal locus of control regarding ulcer prevention, and more negative attitudes to the appearance and price of therapeutic shoes and how they felt about wearing them in public. Other comparisons were non-significant: other shoe attributes, education, diabetes type, current foot ulcers, major amputations, satisfaction with shoe services, understanding of neuropathy as a risk factor, locus of control regarding ulcer healing, belief in the shoes' efficacy to prevent and heal ulcers, worries about ulcer healing and new ulcerations, self-efficacy, depression, shoe use/adherence, paying a fee for therapeutic shoes, and social support.

Conclusions: Men had worse foot complications. Women had worse general health, lower internal locus of control regarding ulcer prevention, and more negative attitudes toward therapeutic shoes. Clinicians should pay more attention to their female patients' concerns. Future research and development should focus on improving the weight and appearance of therapeutic shoes, particularly for women. Research is also needed on how to facilitate the adaption and reevaluation process where patients change from viewing shoes purely as items of clothing to also viewing them as medical interventions.

Background: Non-removable knee-high devices are the gold standard to treat diabetic foot ulcers located on the plantar forefoot, but they immobilize the ankle, which restricts daily life activities and has negative effects on joint functioning.Objective: To investigate the feasibility of sealing a therapeutic shoe to off-load and heal diabetic forefoot ulcers.

Design: A case series of seven men with type 2 diabetes and a metatarsal head ulcer were prescribed therapeutic shoes and custom-made insoles. The shoe was sealed with a plastic band. Off-loading was assessed with the F-scan pressure measurement system. Adherence to wearing the shoe was assessed with a temperature sensor and by documenting the status of the seal.

Results: The off-loading was effective and all ulcers healed. Median time to healing was 56 days (range 8-160). Complications were secondary ulcer (n = 1) and plantar hematoma (n = 1). Five of seven participants did not disturb the seal.

Conclusions: Sealing a therapeutic shoe is a feasible way to off-load and heal forefoot ulcers. A controlled trial is needed to compare the effectiveness and safety of a sealed shoe to other non-removable devices.

BACKGROUND

Deficits in calf muscle performance and altered lower limb kinetics exist in patients after an Achilles tendon rupture (ATR). However, the influence of fatigue on functional performance is unclear. The aim of this study was to determine the effect of fatigue on a single-leg drop counter movement jump (drop CMJ) after an ATR.

MATERIAL AND METHODS

Twenty-seven subjects (22 male) with the mean (SD) age of 42.8 (9.3) years were evaluated 23.5 (8.4) months after ATR. Conventional motion capture procedures were used for data collection as participants performed drop CMJs before and after a standard fatigue protocol, consisting of bilateral single-leg standing heel-rise test followed by a 5-minute progressive slide board protocol. Data analysis focused on: a) eccentric and concentric ankle joint power (AJP); b) time from initial contact to peak eccentric and concentric AJP.

RESULTS

A significant limb by fatigue interaction was found for both eccentric (involved -0.83 W/kg; uninvolved -1.44 W/kg, p<0.001) and concentric AJP (involved -0.20 W/kg; uninvolved -0.71 W/kg, p<0.001), reflecting greater effects of fatigue on the uninvolved side. There was also significant difference in how fatigue delayed time to peak power during concentric (involved 15ms; uninvolved 29ms, p<0.001) but not eccentric AJP (p=0.854)

CONCLUSION

Fatigue had a greater effect on the uninvolved compared to the involved side. Since the uninvolved side seems to compensate for deficits in the involved side, there is a risk that the uninvolved side is more prone to injuries when returning back to sports after an ATR.

Under det senaste decenniet har det blivit allt vanligare med arbetsrelaterade besvär hos uniformerad polis i yttre tjänst, främst är det besvär från nedre delen av ryggen som uppgetts. Hälsohögskolan i Jönköping har fått i uppdrag av Rikspolisstyrelsen att belysa och utreda den uppkomna problematiken. Två tidigare rapporter, Polisens fysiska arbetsmiljö och Polisens psykosociala miljö, har presenterats. I rapporten om polisens fysiska arbetsmiljö framkom en hög förekomst av besvär från muskler och leder, främst nedre delen av ryggen under förhållande med bärande av utrustningsbältet i kombination med mycket stillasittande i tjänstebilar. I den andra rapporten framkom att en stor del av poliserna arbetar treskift och i många fall långa arbetspass, vilket yttrar sig i att de har svårt att psykiskt återhämta sig, inte har tid för familj och vänner samt att de ofta upplever sig trötta. I den tredje och sammanfattande rapporten presenteras vilka bakomliggande variabler som påverkar den fysiska och psykosociala arbetsmiljön.

Syftet med studien var att analysera vilka variabler och vilka kombinationer av variabler som påverkar den fysiska och psykosociala arbetsmiljön för uniformerad polis i yttre tjänst i Sverige. Rapporten baseras på 4244 enkätsvar från poliser i yttre uniformerad tjänst.

Resultatet från föreliggande studie har visat att det finns skillnaden i besvärsfrekvens mellan myndigheterna när det gäller otillräcklig fysisk och psykisk återhämtning samt besvär ifrån nedre delen av ryggen. Orsakerna till skillnaden mellan myndigheterna är inte utredda. Studien har visat att besvärsfrekvensen ökar då det föreligger krav att arbeta på ett rullande treskiftsschema. Utifrån detta föreslår vi att man:

• utför benchmarking av polismyndigheter för att öka förståelsen för de stora skillnader som förekommer

• utvärderar olika modeller av schemaläggning avseende treskift

• fortsätter arbetet med att utreda hur polisens uniform och kroppsburna utrustning, i kombination med bilsätets utformning, påverkar besvär från nedre delen av ryggen.

Purpose: Musculoskeletal disorders are considered as a major issue affecting the health and well-being of active duty police. Discomfort from wearing mandatory equipment and sitting for long periods of time in fleet vehicles are workload factors linked to musculoskeletal disorders in police. This study aims to determine the prevalence of multi-site musculoskeletal pain among Swedish police and to explore the possible association to discomfort experience when wearing mandatory equipment and sitting for long periods in fleet vehicles.

Methods: In this cross-sectional study responses from 4185 police were collected through a self-administered online survey including questions about physical work environment, mandatory equipment and musculoskeletal pain. Multi-site pain was determined through summing pain sites from four body regions. Binomial logistic regression was performed to explore the association between multi-site musculoskeletal pain: (1) discomfort from wearing mandatory equipment and (2) sitting for long periods in fleet vehicles.

Results: The prevalence of multi-site musculoskeletal pain at least 1 day per week within the previous 3 months was 41.3%. A statistically significant association between discomfort from wearing mandatory equipment and multi-site musculoskeletal pain was found; duty belt [OR 5.42 (95% CI 4.56–6.43)] as well as body armour [OR 2.69 (95% CI 2.11–3.42)]. Sitting for long periods in fleet vehicles was not significantly associated to multi-site musculoskeletal pain.

Conclusion: Multi-site musculoskeletal pain is a considerable problem among Swedish police and modifying mandatory equipment to decrease discomfort is suggested as a potential means of decreasing the musculoskeletal pain experienced by many police officers. 

Police working in active duty have a high prevalence of musculoskeletal pain, with lower back pain being the most frequently reported. As a part of uniform regulations, Swedish police are mandated to wear body armour and duty belts at all times during work. This study aimed to investigate the effect of different load carriage designs on in-vehicle sitting pressure and self-rated discomfort among police. Results showed less discomfort when wearing the alternate load carriage system incorporating a load-bearing vest and thigh holster compared to the standard load carriage system consisting of a duty belt. Pressures in the lower back were reduced when wearing the load-bearing vest whereas pressures in the upper back region increased. Relocating appointments away from the waist has the potential to improve sitting positions and the ergonomic situation for police when driving fleet vehicles.

Background: Body armour, duty belts and belt mounted holsters are standard equipment used by the Swedish police and have been shown to affect performance of police specific tasks, to decrease mobility and to potentially influence back pain. This study aimed to investigate the effects on gait kinematics and kinetics associated with use of an alternate load carriage system incorporating a thigh holster.

Methods: Kinematic, kinetic and temporospatial data were collected using three dimensional gait analysis. Walking tests were conducted with nineteen active duty police officers under three different load carriage conditions: a) body armour and duty belt, b) load bearing vest, body armour and thigh holster and c) no equipment (control).

Findings: No significant differences between testing conditions were found for temporospatial parameters. Range of trunk rotation was reduced for both load carriage conditions compared to the control condition (p < 0.017). Range of hip rotation was more similar to the control condition when wearing thigh holster rather than the belt mounted hip holster (p < 0.017). Moments and powers for both left and right ankles were significantly greater for both of the load carriage conditions compared to the control condition (p < 0.017).

Interpretation: This study confirms that occupational loads carried by police have a significant effect on gait kinematics and kinetics. Although small differences were observed between the two load carriage conditions investigated in this study, results do not overwhelmingly support selection of one design over the other.

INTRODUCTION: In previous studies, stance widths are most often determined as a percentage of shoulder width, where 70% of shoulder width is considered a narrow stance width and 140% of shoulder width is considered a wide stance width. A few studies have also normalized stance width to the width of the hips (distance between trochanters). However, there are also a possibility to normalize stance width in relation to the length of the lower extremities, since this variable might not change as much in dynamic situations and may correlate higher to the angle of the lower extremity in a frontal plane. 

AIM: This study aims to compare measurements of stance width when normalized to shoulder width, hip width and leg length for three different stance widths with feet attached to a board. 

METHOD: Motion capture (Qualisys, 16 Oqus-cameras) was used to measure 7 active male kitesurfers with their feet attached to a kiteboard (136 cm). They were 20-28 years old, in average 180 cm (SD=7 cm) and 78 kg (SD=7 kg). The subjects were standing with three different stance widths, using the same external rotation (20° bilaterally). Markers were attached to shoulders (acromion processes), knee joint lines, hips (trochanter major), heels (mid-posterior of calcaneus) and ankles (lateral and medial malleoli). Stance width was measured as the distance between the two medial ankle markers and normalized towards the distances between (1) the shoulder markers, (2) the hip markers and knee marker plus knee marker and lateral ankle marker and (3) the right and left hip marker. Furthermore, the angle of an extended lower extremity towards a vertical line in the frontal plane was measured. All measurements were done twice, and SPSS 20 was used for data analysis of correlation (Pearson’s r). 

RESULTS: The measured stance widths between ankles were 39.9 cm, 43.6 cm, and 48 cm (SD=1.2-1.4) for all subjects. The correlations (r) between the angle of the leg towards a vertical line and normalized stance width for the three normalization variables were: (1) 0.79, (2) 0.96 and (3) 0.93. All of the correlations were significant at a level of p&gt;0.01. 

CONCLUSION: The results show that the variables hip or leg length would be preferred to use when normalizing stance width for young male athletes, standing in wide stance widths. Further studies using a greater number of subjects, more stance widths and a more heterogeneous group are suggested for the future.

Objectives: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

The gold standard for gait analysis, in-lab 3D motion capture, is not routinely used for clinical assessment due to limitations in availability, cost and required training. Inexpensive alternatives to quantitative gait analysis are needed to increase the its adoption. Inertial sensors such as accelerometers and gyroscopes are promising tools for the development of wearable gait analysis (WGA) systems. The present study evaluates the use of a WGA system on hip-arthroplasty patients in a real clinical setting. The system provides information about gait symmetry and normality. Results show that the normality measurements are well correlated with various quantitative and qualitative measures of recovery and health status.

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.

Gait analysis (GA) is an important tool in the assessment of several physical and cognitive conditions. The lack of simple and economically viable quantitative GA systems has hindered the routine clinical use of GA in many areas. As a result, patients may be receiving sub-optimal treatment. The present study introduces and evaluates measures of gait symmetry and gait normality calculated from inertial sensor data. These indices support the creation of mobile, cheap and easy to use quantitative GA systems. The proposed method was compared to measures of symmetry and normality derived from 3D kinematic data. Results show that the proposed method is well correlated to the kinematic analysis in both symmetry (r=0.84, p<0.0001) and normality (r=0.81, p<0.0001). In addition, the proposed indices can be used to classify normal from abnormal gait.

Each measure of Achilles tendon length and function has independent associations with ankle kinematics during gait. Plantarflexion at push off is important to raise the body center of mass and accelerate the leg into the swing phase. In order to restore normal gait kinematics, clinicians should evaluate all aspects of Achilles tendon length and function.

Background: Deficits in plantarflexor function are common after an Achilles tendon rupture. These deficits may result in an altered distribution of joint loads during lower extremity tasks. Hypothesis: We hypothesized that, regardless of treatment, the Achilles tendon-ruptured limb would exhibit deficits in ankle kinematics and joint power while exhibiting elevated knee joint power and patellofemoral joint loads during walking, jogging, and hopping. We further hypothesized that this loading pattern would be most evident during jogging and hopping. Methods: Thirty-four participants (17 participants treated surgically, 17 treated nonsurgically) were tested at a mean 6.1 +/- 2.0 years after an Achilles tendon rupture. Lower extremity kinematics and kinetics were assessed while participants completed walking, jogging, and single-legged hopping trials. Patellofemoral joint stress was calculated via a musculoskeletal model. Data were analyzed via mixed-model repeated analyses of variance (alpha = .05) and the limb symmetry index (LSI). Results: No differences (P >= .05) were found between the surgical and nonsurgical groups. In both groups, large side-to-side deficits in the plantarflexion angle at toeoff (LSI: 53.5%-73.9%) were noted during walking, jogging, and hopping in the involved limb. Side-to-side deficits in the angular velocity were only present during jogging (LSI: 93.5%) and hopping (LSI: 92.5%). This pattern was accompanied by large deficits in eccentric (LSI: 80.8%-94.7%) and concentric (LSI: 82.2%-84.7%) ankle joint powers in the involved limb during all tasks. Interestingly, only jogging and hopping demonstrated greater knee joint loads when compared with the uninvolved limb. Concentric knee power was greater during jogging (LSI: 117.2%) and hopping (LSI: 115.9%) compared with the uninvolved limb. Similarly, peak patellofemoral joint stress was greater in the involved limb during jogging (LSI: 107.5%) and hopping (LSI: 107.1%), while only hopping had a greater loading rate of patellofemoral joint stress (LSI: 110.9%). Conclusion: Considerable side-to-side deficits in plantarflexor function were observed during walking, jogging, and hopping in patients after an Achilles tendon rupture. As a possible compensation, increased knee joint loads were present but only during jogging and hopping. Clinical Relevance: These data suggest that after an Achilles tendon rupture, patients may be susceptible to greater mechanical loading of the knee during sporting tasks, regardless of surgical or nonsurgical treatment.

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).

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. 

BACKGROUND: Patient reported outcome measurement (PROMs) will not capture in detail the functional joint motion before and after total hip arthroplasty (THA). Therefore, methods more specifically aimed to analyse joint movements may be of interest. An analysis method that addresses these issues should be readily accessible and easy to use especially if applied to large groups of patients, who you want to study both before and after a surgical intervention such as THA. Our aim was to evaluate the accuracy of inertial measurement units (IMU) by comparison with an optical tracking system (OTS) to record pelvic tilt, hip and knee flexion in patients who had undergone THA.

METHODS: 49 subjects, 25 males 24 females, mean age of 73 years (range 51-80) with THA participated. All patients were measured with a portable IMU system, with sensors attached lateral to the pelvis, the thigh and the lower leg. For validation, a 12-camera motion capture system was used to determine the positions of 15 skin markers (Oqus 4, Qualisys AB, Sweden). Comparison of sagittal pelvic rotations, and hip and knee flexion-extension motions measured with the two systems was performed. The mean values of the IMU's on the left and right sides were compared with OTS data.

RESULTS: The comparison between the two gait analysis methods showed no significant difference for mean pelvic tilt range (4.9-5.4 degrees) or mean knee flexion range (54.4-55.1 degrees) on either side (p > 0.7). The IMU system did however record slightly less hip flexion on both sides (36.7-37.7 degrees for the OTS compared to 34.0-34.4 degrees for the IMU, p < 0.001).

CONCLUSIONS: We found that inertial measurement units can produce valid kinematic data of pelvis- and knee flexion-extension range. Slightly less hip flexion was however recorded with the inertial measurement units which may be due to the difference in the modelling of the pelvis, soft tissue artefacts, and malalignment between the two methods or misplacement of the inertial measurement units.

TRIAL REGISTRATION: The study has ethical approval from the ethical committee "Regionala etikprövningsnämnden i Göteborg" (Dnr: 611-15, 2015-08-27) and all study participants have submitted written approval for participation in the study.