Hinesle5034
BACKGROUND The Parkinson's disease Postural Instability and Gait Difficulty subtype is well-known to exhibit higher levels of gait and postural instability and higher frequency of falls. However, no studies have investigated the impact of Parkinson's disease subtypes when performing a highly-challenging postural task, such as sit-to-walk. This task is often used daily and can highlight balance impairments. Thus, the aim of this study was to compare Tremor Dominant and Postural Instability and Gait Difficulty subtypes during sit-to-walk measured by performance, kinematic and kinetic analyses. METHODS Twenty-four people with Parkinson's disease participated in this study, and were divided into two groups Tremor Dominant (n = 14) and Postural Instability and Gait Difficulty subtype (n = 10). They performed the sit-to-walk under a time constraint (to pick up a phone placed 4 meters away in order to answer an urgent call). Sit-to-walk overall performance, kinetic and kinematic data were assessed as outcome measures. FINDINGS The Postural Instability and Gait Difficulty group demonstrated a slower anteroposterior center-of-mass velocity at seat-off, a longer duration of transitional phase and poorer movement fluidity. Furthermore, the Postural Instability and Gait Difficulty group showed a longer sit-to-walk total time. These results indicate that the Postural Instability and Gait Difficulty group performed the task slowly and split the task into two subtasks (sit-to-stand and walking), rather than performing a single, continuous task. INTERPRETATION The Postural Instability and Gait Difficulty group is unable to perform the sit-to-walk continuously, which might reflect the clinical impairments observed in this Parkinson's disease subtype. BACKGROUND A structural differentiation maneuver has been proposed to differentiate between muscle and nerve involvement during the straight leg raise test. However, to date, the mechanical specificity of this maneuver for the tibial nerve at the posterior knee has not been tested. The aim of this study was to investigate the specificity of ankle dorsiflexion as a differentiation maneuver between the tibial nerve and the biceps femoris muscle at the posterior knee during the straight leg raise in cadavers. METHODS A cross-sectional study was carried out. In fresh frozen cadavers, with microstrain devices and Vernier calipers, strain and excursion in the tibial nerve and distal biceps femoris muscle were measured during ankle dorsiflexion at 0°, 30°, 60° and 90° of hip flexion of the straight leg raise. FINDINGS Ankle dorsiflexion resulted in significant distal excursion and increased strain in the tibial nerve (p 0.05) at all hip flexion angles. INTERPRETATION Ankle dorsiflexion was mechanically specific between the tibial nerve and biceps femoris during the straight leg raise. This study adds to evidence that, in certain circumstances, dorsiflexion may be used in differentiation of nerve and muscle disorders in the posterior knee. BACKGROUND Recent studies presented that increased adiposity and hyperlipidemia may cause tendon pathology. The aim of this study was to evaluate the effect of hyperlipidemia on the patellar tendon stiffness by shear wave elastography. METHODS A total of 51 participants (19 female, 32 male) were included. Participants were divided into two groups, according to their low-density lipoprotein levels, as the study group (hyperlipidemia, n = 24) and the control group (non-hyperlipidemia, n = 27). The patellar tendon and rectus femoris muscle shear wave velocities were measured by shear wave elastography. FINDINGS Patellar tendon shear wave velocities was 5.02 (SD 0.78) m/s in the control group and 5.98 (SD 1.19) m/s in the hyperlipidemia group (ES = 0.95, P = .001). There was a positive moderate statistically significant correlation between patellar tendon shear wave velocity and low-density lipoprotein (r = 0.432, p less then .002). In the multiple linear regression analysis, only low-density lipoprotein was found as a significant predictor of patellar tendon shear wave velocity (CI 0.005-0.028, P = .007). INTERPRETATION We evaluated the effects of hyperlipidemia and body mass index on patellar tendon mechanical properties with shear wave elastography. We found that the blood low-density lipoprotein level had an impact on patellar tendon stiffness independently of body mass index. Accordingly, it is important to evaluate individuals' low-density lipoprotein levels when examining risk factors for tendon pathology. BACKGROUND Aim of this biomechanical study was to investigate the anchorage of pedicle screws in osteoporotic vertebrae using two different preparation techniques (probe versus drill-assisted). METHODS Twelve thoracic vertebrae were used for the study. The right and left pedicles of the vertebra were prepared with a thoracic probe or a 3.2 mm drill bit and divided into two groups. A standard titanium (diameter 5.5 mm, length 45 mm) pedicle screw was then inserted. SAR405838 All pedicle screws were initially loaded with -25 N to +25 N in the cranio-caudal direction. The load was increased by 5 N every 500 cycles up to a maximum load of 10,000 cycles. Loosening was defined as a displacement of the pedicle screw head of >5 mm. The two groups were compared in terms of maximum number of cycles and maximum force until loosening. FINDINGS The pedicle screws prepared with the thoracic probe failed on average after 3819 cycles (SD 3281) and the pedicle screws prepared with the 3.2 mm drill after 3335 cycles (SD 3477). There was no significant difference between the two preparation techniques (P = .797). With regard to the maximum force until loosening, there was also no significant difference between the two techniques (thoracic probe 61 N (SD 33), 3.2 mm drill bit 56 N (SD 34), P = .791). INTERPRETATION Preparation of the pedicle screw hole either with a probe or drill bit doesn't seem to have an influence on pedicle screw loosening rates in the osteoporotic spine. BACKGROUND Trunk function and lower limb strength seem to be the primary predictors for functional independence in acute stroke patients. Gaining a better understanding of their relationship during walking aids in the identification of intrinsic trunk control deficits and underlying lower limb deficits resulting in compensatory trunk movements. METHODS Fifty-seven subjects with stroke and 57 age- and gender-matched subjects without disability were included. Participants underwent an instrumented gait analysis with a standard total body Plug-In-Gait model, a clinical examination of the lower limbs based on range of motion, strength, muscle tone and several clinical assessment scales such as the Trunk Impairment Scale, Tinetti test and Functional Ambulation Categories. Spatiotemporal parameters and joint angular time profiles were compared between healthy adults and stroke survivors with severe and mild to moderate lower limb impairments. Spm1d was used to compare the joint angular time profiles between groups.