Introduction

Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional deformity of the spine with unclear etiology. Due to the asymmetry of lateral curves, there are differences in the muscle activation between the convex and concave sides. This study utilized a comprehensive thoracic spine and ribcage musculoskeletal model to improve the biomechanical understanding of the development of AIS deformity and approach an explanation of the condition.

Achilles tendon (AT) rupture may lead to complaints of heel pain. In forefoot ulcer patients AT lengthening is used to transfer pressure from forefoot to the heel. The primary aim was to investigate if AT was longer or associated with changes in pedobaric measurements, in particular heel pressure, on the injured leg 4–5 years after the injury.

Achilles tendon rupture may lead to significant functional deficits, which mechanisms are poorly understood. The primary aim was to investigate if the Achilles tendon (AT) was longer, muscles weaker or gait changed on the injured leg 4–5 years after the injury. Secondary aim was to compare functional outcomes with patient reported Achilles Tendon Total Rupture Score (ATRS).

We invited all participants from an RCT of conservatively treated AT Rupture (ATR) with or without early weight-bearing (early-WB, non-WB), and 12 moths of follow up. Of the original 56, 37 patients participated, 19 from early-WB (1 re-rupture (RR)), and 18 from non-WB (2 RR). Time from injury to follow up was 4,5 years (4,1 to 5,1). AT length was measured using ultrasound with a validated protocol (Barfod K.W. et al.). Heel raise work was measured on a 10 degree inclining platform. The exercise lasted until the patient could not maintain frequency or height of lift. Number and height of lift was measured using reflective markers in a Vicon system, and total work calculated. Foot pressure mapping (FPM) was measured barefoot, using an EMED platform (novel, Germany). Statistics: T-test for limb to limb comparisons and linear regression for ATRS correlations was applied.

Including RR in the sample did not impact the results. We found no differences in any of the variables between the early-WB and non-WB groups. Compared to the uninjured limb, the Achilles tendon was an average of 1,8 (1,2–2,3) cm longer on the injured limb, which produced 40% less work. A smaller calf circumference (p < 0.001), larger dorsiflextion (p = 0.001), and Achilles tendon resting angle (p < 0.001) was found for the injured limb. Difference in mean medial forefoot peak pressure was approaching significance (healthy 484 (SD 165) KPa, injured: 439 (SD 160), p = 0.08). Similarly the difference in pressure / time integral of the medial forefoot was approaching significance (Healthy: 129 (SD 35)KPa, injured: 115 (SD 44)KPa, p = 0.08). Duration of contact time of the heel was extended and heel lift off was delayed in the injured limb (p = 0.02 for both). ATRS could not be linked to Achilles tendon length or total work using linear regression.

Conservatively treated Achilles tendon ruptures were approximately 1,8 cm longer. The limb was persistently weaker. A subtle change in heel contact duration and time of heel rise could be detected on the injured limb. ATRS does not appear to correlate directly with AT length or loss of total work.

Increase in heel height increases peak pressure under the forefoot. Customized shoe inlays with metatarsal lift, arch support has demonstrated lowered forefoot pressure and increase in the subjective comfort. A commercial shoe brand (Roccamore) has introduced an off-the-rack stiletto with a slim (1 cm²) 8 cm heel plus 2 cm platform with metatarsal lift, arch support and heel cap claiming it will reduce the discomfort associated with high heels. The primary aim of this study was to compare the pressure under the forefoot, arch, heel and toes in this “orthopaedic” stiletto (OS) to a standard stiletto of the same heel height without inlays (SS) and a control sneaker (SN). Secondary aims were to measure the comfort under the forefoot, heel and arch during everyday use. Finally to investigate if any pressure measurements were correlated to comfort or any anatomical/clinical feature of the foot.

22 women, aged 40 (21–62), accustomed to stilettos, walked at 4 km/hr on a level treadmill in all three shoe types. Peak pressure (kPa) and pressure-time integral (kPa/sec) under 2+3rd and first metatarsal heads, the arch/midfoot and heel were measured during 10 consecutive steps at 50 Hz using Novel Pedar-X pressure distribution insoles. Standing X-rays and a standardized clinical examination were carried out. Mundermanns comfort VAS and daily steps were recorded for each shoe type during 3 full days. (0= worst to 150 mm= most comfortable). Data were compared with paired t-tests and regression analysis. Statistical significance is reported as p<0.05=, p<0.01=, p<0.001=.

Peak pressure: Compared to SS the peak pressure under the 2+3 metatarsals was reduced to 82% in the OS and 60% in the SN. Under the first metatarsal it was reduced to 73% and 40%, respectively. Under the arch it was similar for SN and OS and 30% lower for the SS. Under the heel the OS was 27–28% lower than SS and SN.

The same reductions, as well as similarities in the arch were seen in the pressure-time integrals, although with smaller difference between OS and SS, and conversely larger reductions in the SN to 49% under 2+3 metatarsals and 43% under the first.

For forefoot, arch and heel, the comfort was rated highest for the SN and lowest for the SS. No statistical difference between OS and SS in the arch.

For each mm the second metatarsal was longer than the first, the peak pressure under MT2+3 rose 13 kPa (95%CI: 7 to 19) and the pressure time integral 3 kPa/s (1–5). No effect of first ray ROM or stability. The forefoot VAS score dropped (less comfortable) 0.3 mm for each kPa/s the pressure time integral rose under the MT2+3. Peak pressure parameters or daily steps were not statistically significantly related to the forefoot comfort.

A mass produced “orthopaedic” stiletto can reduce the pressure approaching those achieved in a sneaker and increase comfort for the user. An increase in pressure-time integral under 2+3 metatarsals increases the discomfort and the pressure is increased in index-minus feet.

Introduction: Single leg hop for distance is a test often used as a measure of knee performance and stability during rehabilitation after knee surgery or injury. Both distance hopped and qualitative assessment of stability in landing is widely used as parameters of knee joint control. While hop distance is reported as highly reliable, no investigations have studied the reliability of the biomechanical parameters expressing the quality of the landing after a single leg hop. The aim of the present study was to investigate the reliability of hop distance and biomechanical landing parameters during a single leg hop test.

Methods: The study was designed as an intra-tester, inter-day test-retest reliability study. Fourteen (7 males, 7 females) physically active, healthy subjects volunteered to participate. The subjects performed 5 maximal single leg hops for distance including 2 trial jumps, and the mean of the last 3 hops was used for analysis. The test session was repeated after 1 week. In both sessions the same tester placed markers on the lower body (Helen Hayes model) and the subjects landed after maximal hopping on a force plate. The hops were recorded using an 8 camera Vicon 612 system filming at 200 Hz. Kinematic and kinetic data were calculated using inherent Vicon software. Intraclass Correlation Coefficient (2,1) was used for analysis of reliability on selected kinematic and kinetic knee joint parameters.

Results: The ICC of the maximal hop distance was excellent (0.93, p< 0.001). The reliability of the maximal knee joint flexion during landing was poor and non-significant, and also peak knee extensor moment during landing showed poor reliability (ICC: 0.48, p=0.037). The maximal external knee joint varus moment and the relative eccentric power production of the knee joint in comparison to the hip and ankle joints were moderately reliable (ICC: 0.56, p=0.015, and ICC: 0.64, p=0.005, respectively).

Conclusions: This study shows, that in healthy subjects the reliability of the maximal hop distance is excellent, however the underlying biomechanical parameters controlling the knee joint during landing is only moderately or poorly reliable. This may imply, that the subjects use slightly different strategies during landing from the hop and evaluation of knee joint performance based on landing biomechanics may be done with caution. Future reliability and validation studies of the take-off biomechanics may further reveal if the single leg hop test is reliable and valid as a measure of knee joint performance.

Objectives: To investigate

if subjects with medial tibial stress syndrome demonstrate increased navicular drop and medial longitudinal-arch deformation during quiet standing and gait compared to healthy subjects,

Methods: Thirty subjects aged 20–32 yrs were included (15 with medial tibial stress syndrome and 15 controls). Navicular drop and medial longitudinal-arch deformation were measured during quiet standing with neutral and loaded foot using a ruler and digital photography. Medial longitudinal-arch deformation was measured during walking gait using 3-dimensional gait analysis.

Results: Subjects with medial tibial stress syndrome demonstrated a significantly larger navicular drop (mean ± 1 SD, 7.7 ± 3.1 mm) and medial longitudinal-arch deformation (5.9 ± 3.2 deg) during quiet standing compared to controls (5.0 ± 2.2 mm and 3.5 ± 2.6 deg, P < 0.05). Subjects with medial tibial stress syndrome also demonstrated significantly larger medial longitudinal-arch deformation (8.8 ± 1.8 deg) during gait compared to controls (7.1 ± 1.7 deg, P = 0.015). There was no correlation between medial longitudinal-arch deformation during quiet standing and gait in either of the two groups (r < 0.127, P > 0.653).

Conclusion: The subjects with medial tibial stress syndrome in this study demonstrated increased navicular drop and medial longitudinal-arch deformation during quiet standing and increased medial longitudinal-arch deformation during gait compared to healthy subjects. Medial longitudinal-arch deformation during quiet standing did not correlate with medial longitudinal-arch deformation during gait in either of the two groups.