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Purpose: Discomfort during cycling can be counteracted by adjusting the seat position. However, the influence of changes in cycling position regarding quantitative biomechanical adaptions of the upper body in recreational cyclists is unclear. This study aims to investigate the effects of saddle position and reach distance on upper body kinematics and muscle activation. Methods: Twelve recreational cyclists were investigated in four different sitting positions on an adjustable cycle trainer. Trunk, pelvis, shoulder, elbow and spinal kinematics as well as lower back and elbow extensor activity were analyzed for combinations of normal and shortened reach distance including horizontal and 10° downward inclined saddle positions. Results: An inclined saddle increased activation of elbow extensors by almost 23 [plus or minus] 8% (p < 0.01) while a shortened reach distance resulted in a more posterior pelvic tilt of up to 18 [plus or minus] 2% (p < 0.01) and less trunk forward lean of 10 [plus or minus] 9% (p < 0.01). Shoulder flexion reduced by up to 23 [plus or minus] 16% (p < 0.05) while elbow flexion increased by 15 [plus or minus] 22% (p < 0.05) with a shortened reach distance. No differences between configurations were found for spinal kinematics and lower back muscle activity. Conclusions: Changing the reach distance showed considerable biomechanical effects on upper body kinematics of the pelvis and trunk rather than on the spine or on lower back muscle activity. For reach distance, most compensation of postural changes of the upper body occurred by changes of shoulder and elbow angles while elbow extensor activation was only altered by saddle downward inclination.

Objective Methods Results Conclusion Level of Evidence Evaluation of long‐leg standing radiographs (LSR) is a standardised procedure for analysis of primary or secondary deformities of the lower limbs. Deep‐learning convolutional neural networks (CNN) offer the potential to enhance radiological measurement by increasing reproducibility and accuracy. This study aims to evaluate the measurement accuracy of an automated CNN‐based planning tool (mediCAD® 7.0; mediCAD Hectec GmbH) of lower limb deformities.In a retrospective single‐centre study, 164 pre‐ and postoperative bilateral LSRs with uni‐ or bilateral posttraumatic knee arthritis undergoing total knee arthroplasty (TKA) were enroled. Alignment parameters relevant to knee arthroplasty and deformity correction were analysed independently by two observers and a CNN. The intraclass correlation coefficient (ICC) was used to evaluate the accuracy between observers and the CNN, which was further evaluated using absolute deviations, limits of agreement (LoA) and root mean square error (RMSE).CNN evaluation demonstrated high consistency in measuring leg length (ICC > 0.99) and overall lower limb alignment measures of mechanical tibio‐femoral angle (mTFA) (ICC > 0.97; RMSE < 1.1°). The mean absolute difference between angular measurements were low for overall lower limb alignment (mTFA 0.49–0.61°) and high for specific joint angles (aMPFA 3.86–4.50°). Accuracy at specific joint angles like the mechanical proximal tibial angle (MPTA) and the mechanical lateral distal femur angle (mLDFA) varied between lower limbs with deformity, with and without TKA with greatest difference for TKA (ICC 0.22–0.85; RMSE 1.72–3.65°).Excellent accuracy was observed between manual and automated measurements for overall alignment and leg length, but joint‐level metrics need further improvement especially in case of TKA similar to other existing algorithms. Despite the observed deviations, the time‐efficient nature of the algorithm improves the efficiency of the preoperative planning process.IV [ABSTRACT FROM AUTHOR]

Background: Tibial shaft fractures require surgical stabilization preferably by intramedullary nailing. Recovery is often unsatisfactory due to limited knee function and pain, resulting in reduced quality of life. The extent of these functional limitations with respect to gait deficits has not been sufficiently recognized.Research Question: Are there functional limitations during gait and squat performance during the first six months after surgically treated tibial shaft fractures?Methods: Twenty-three patients (BMI: 24 ± 3, Age:39 ± 15) with tibial shaft fractures and 23 healthy, matched controls (BMI: 24 ± 3, Age: 40 ± 14) were assessed using instrumented motion analysis two, three and six months after surgery. Kinematic and kinetic data of the lower extremities were collected during level walking and squat performance. Data were compared among follow-up time intervals and between groups.Results: Significant improvements were found for all spatiotemporal parameters and most kinetic parameters. Even six months after surgery functional deficits persisted when compared to healthy controls. There were only slight improvements in sagittal knee and ankle kinematics as well as knee moments and power within the follow-up period. A significant difference compared to the healthy controls can still be observed in these parameters.Significance: Although patients with tibia fractures demonstrated functional improvements over the early course of healing, some residual deficits in lower extremity movement biomechanics were identified at six months post surgery. In particular knee kinematics in squatting as well as knee kinematics and kinetics during walking only recovered incompletely. This result can help explain the often-reported functional limitations.Clinical Trial Registration Number: German register for clinical trials (DRKS00023790). [ABSTRACT FROM AUTHOR]