Movement Behavior of High-Heeled Walking: How Does the Nervous System Control the Ankle Joint during an Unstable Walking Condition?

The human locomotor system is flexible and enables humans to move without falling even under less than optimal conditions. Walking with high-heeled shoes constitutes an unstable condition and here we ask how the nervous system controls the ankle joint in this situation? We investigated the movement behavior of high-heeled and barefooted walking in eleven female subjects. The movement variability was quantified by calculation of approximate entropy (ApEn) in the ankle joint angle and the standard deviation (SD) of the stride time intervals. Electromyography (EMG) of the soleus (SO) and tibialis anterior (TA) muscles and the soleus Hoffmann (H-) reflex were measured at 4.0 km/h on a motor driven treadmill to reveal the underlying motor strategies in each walking condition. The ApEn of the ankle joint angle was significantly higher (p<0.01) during high-heeled (0.38±0.08) than during barefooted walking (0.28±0.07). During high-heeled walking, coactivation between the SO and TA muscles increased towards heel strike and the H-reflex was significantly increased in terminal swing by 40% (p<0.01). These observations show that high-heeled walking is characterized by a more complex and less predictable pattern than barefooted walking. Increased coactivation about the ankle joint together with increased excitability of the SO H-reflex in terminal swing phase indicates that the motor strategy was changed during high-heeled walking. Although, the participants were young, healthy and accustomed to high-heeled walking the results demonstrate that that walking on high-heels needs to be controlled differently from barefooted walking. We suggest that the higher variability reflects an adjusted neural strategy of the nervous system to control the ankle joint during high-heeled walking

The highly accurate anteriolateral portal for injecting the knee

<p>Abstract</p> <p>Background</p> <p>The extended knee lateral midpatellar portal for intraarticular injection of the knee is accurate but is not practical for all patients. We hypothesized that a modified anteriolateral portal where the synovial membrane of the medial femoral condyle is the target would be highly accurate and effective for intraarticular injection of the knee.</p> <p>Methods</p> <p>83 subjects with non-effusive osteoarthritis of the knee were randomized to intraarticular injection using the modified anteriolateral bent knee versus the standard lateral midpatellar portal. After hydrodissection of the synovial membrane with lidocaine using a mechanical syringe (reciprocating procedure device), 80 mg of triamcinolone acetonide were injected into the knee with a 2.0-in (5.1-cm) 21-gauge needle. Baseline pain, procedural pain, and pain at outcome (2 weeks and 6 months) were determined with the 10 cm Visual Analogue Pain Score (VAS). The accuracy of needle placement was determined by sonographic imaging.</p> <p>Results</p> <p>The lateral midpatellar and anteriolateral portals resulted in equivalent clinical outcomes including procedural pain (VAS midpatellar: 4.6 ± 3.1 cm; anteriolateral: 4.8 ± 3.2 cm; p = 0.77), pain at outcome (VAS midpatellar: 2.6 ± 2.8 cm; anteriolateral: 1.7 ± 2.3 cm; p = 0.11), responders (midpatellar: 45%; anteriolateral: 56%; p = 0.33), duration of therapeutic effect (midpatellar: 3.9 ± 2.4 months; anteriolateral: 4.1 ± 2.2 months; p = 0.69), and time to next procedure (midpatellar: 7.3 ± 3.3 months; anteriolateral: 7.7 ± 3.7 months; p = 0.71). The anteriolateral portal was 97% accurate by real-time ultrasound imaging.</p> <p>Conclusion</p> <p>The modified anteriolateral bent knee portal is an effective, accurate, and equivalent alternative to the standard lateral midpatellar portal for intraarticular injection of the knee.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00651625">NCT00651625</a></p

Is medial calcar continuity necessary in plate osteosynthesis for proximal humerus fractures?

WOS: 000427371000018PubMed: 29519987Objective: To evaluate the functional and radiological results of patients with and without medial calcar continuity in plate osteosynthesis applied for a proximal humerus fracture retrospectively. Methods: The study included 27 patients to whom plate osteosynthesis was applied because of a proximal humerus fracture between January 2, 2010, and December 30, 2013, at Okmeydani Research and Training Hospital. Patients were separated into Group A with medial calcar continuity and Group B without medial calcar continuity. On the radiographs taken postoperatively and at the final follow-up examination, measurements were taken of the humeral head height and the humeral neck-shaft angle. The presence of avascular necrosis was recorded. Results: The functional and radiological results of the patients were evaluated after a mean follow-up of 39.1 months. No statistically significant difference was determined between Groups A and B in respect of the postoperative and the final follow-up humeral head height (P > 0.05). No statistically significant difference was determined between Groups A and B in respect of the postoperative and the final follow-up humeral neck-shaft angle (P > 0.05). Plate breakage was seen in one patient without medial calcar continuity. Penetration of the screw into the joint was determined in one patient in Group A and three patients in Group B. No avascular necrosis or infection was seen in any patient. Conclusion: When the surgical process has not damaged the soft tissue and sufficient stability has been achieved, providing calcar continuity is not an absolute condition

Accuracy of intrasheath injection techniques for de Quervain's disease: a cadaveric study

The purpose of this study was to assess the accuracy of injections of dye into the first extensor compartment of the wrist using three different techniques in 150 wrists in 75 fresh cadavers. To compare injections, 50 wrists from 25 cadavers were used for each technique. After the injections, the first extensor compartment was dissected and the dispersion of dye around the abductor pollicis longus and extensor pollicis brevis tendons was investigated. In 72 % of all the wrists, acrylic dye was dispersed into one compartment containing both the abductor pollicis longus and extensor pollicis brevis tendons, but in 28% of the wrists there was a separate compartment for extensor pollicis brevis and dye entered only one of the compartments (14% for each compartment). For accurate injections, we think the injections should be made separately over the two tendons, to allow for the possibility of a septum within the compartment

A comparison of single- versus double-row suture anchor techniques in a simulated repair of the rotator cuff - An experimental study in rabbits

We compared time-dependent changes in the biomechanical properties of single- and double-row repair of a simulated acute tear of the rotator cuff in rabbits to determine the effect of the fixation techniques on the healing process