Background: Simultaneous measurement of electromyography (EMG) and local muscle oxygenation is proposed in an isometric loading model adjusted for patients that have undergone spinal surgery. Methods: Twelve patients with degenerative lumbar spinal stenosis (DLSS) were included. They were subjected to a test protocol before and after surgery. The protocol consisted of two parts, a dynamic and an isometric Ito loading with a time frame of 60 s and accompanying rest of 120 s. The Ito test was repeated three times. EMG was measured bilaterally at the L4 level and L2 and was recorded using surface electrodes and collected (Biopac Systems Inc.). EMG signal was expressed as RMS and median frequency (MF). Muscle tissue oxygen saturation (MrSO 2) was monitored using a near-infrared spectroscopy (NIRS) device (INVOS® 5100C Oxymeter). Two NIRS sensors were positioned bilaterally at the L4 level. The intensity of the leg and back pain and perceived exertion before, during, and after the test was evaluated with a visual analogue scale (VAS) and Borg RPE-scale, respectively. Results: All patients were able to perform and complete the test protocol pre-and postoperatively. A consistency of lower median and range values was noted in the sensors of EMG1 (15.3 μV, range 4.5-30.7 μV) and EMG2 (13.6 μV, range 4.0-46.5 μV) that were positioned lateral to NIRS sensors at L4 compared with EMG3 (18.9 μV, range 6.5-50.0 μV) and EMG4 (20.4 μV, range 7.5-49.0 μV) at L2. Right and left side of the erector spinae exhibited a similar electrical activity behaviour over time during Ito test (60 s). Regional MrSO 2 decreased over time during loading and returned to the baseline level during recovery on both left and right side. Both low back and leg pain was significantly reduced postoperatively. Conclusion: Simultaneous measurement of surface EMG and NIRS seems to be a promising tool for objective assessment of paraspinal muscle function in terms of muscular activity and local muscle oxygenation changes in response to isometric trunk extension in patients that have undergone laminectomy for spinal stenosis.

The aim was to investigate the rate of athletes still active at their pre-injury sports level two years after arthroscopic treatment for femoroacetabular impingement syndrome (FAIS), and examine this between different sports and gender, and its correlation to patient-reported outcome measures (PROMs). Method: High-level athletes planned for arthroscopic treatment for FAIS were included prospectively in a Swedish hip arthroscopy registry between 2011 and 2017, and 717 met the inclusion criteria. Self-reported sporting activity was recorded preoperatively. The subjects answered PROMs, including the HSAS, iHOT-12 and HAGOS pre-and postoperatively. Results: A total of 551 athletes (median age 26, interquartile range 20-34 years; 23% women) had completed follow-up PROMs, at mean 23.4 ± 7.2 months postoperatively. In total, 135 (24.5%) were active at their pre-injury level of sports at follow-up (RTS pre). Athletes ≤30 years at time of surgery (n = 366; median age 22 years) had higher rate of RTS pre (31.4%) compared with athletes > 30 years (n = 185; median age 40 years) (10.8%; p < 0.001). All athletes had improvements in iHOT-12 and HAGOS, two years postoperatively (p < 0.001), while RTS pre athletes reported significantly better PROMs, pre-and postoperatively, and had greater improvements two years postoperatively, compared with athletes not active at pre-injury level. Conclusion: Only 25% of all high-level athletes and 31% of athletes ≤30 years were still active at their pre-injury sports level two years after arthroscopic treatment for FAIS. Athletes still active had significantly and clinically greater improvement regarding hip symptoms, function and quality of life, as compared with athletes not active at pre-injury level, two years postoperatively.

Purpose To investigate how range of motion of the hips and the lumbar spine are affected by continued elite, alpine skiing in young subjects, with and without a magnetic resonance imaging verified cam morphology, in a 2-year follow-up study. The hypothesis is that skiers with cam morphology will show a decrease in hip joint range of motion as compared with skiers without cam, after a 2-year follow-up. Method Thirty adolescent elite alpine skiers were examined at the baseline (mean age 17.3 ± 0.7 years) and after 2 years. All skiers were examined for the presence of cam morphology (α-angle > 55°) using magnetic resonance imaging at the baseline. Clinical examinations of range of motion in standing lumbar flexion and extension, supine hip flexion, internal rotation, FABER test and sitting internal rotation and external rotation were performed both at the baseline and after 2 years. Results Skiers with and without cam morphology showed a significant decrease from baseline to follow-up in both hips for supine internal rotation (right: mean − 13.3° and − 10.