Quadriceps Surface Electromyography Research Articles

Adductor Canal Nerve Versus Femoral Nerve Blockade for Pain Control and Quadriceps Function Following Anterior Cruciate Ligament Reconstruction With Patellar Tendon Autograft: A Prospective Randomized Trial

To compare femoral nerve blockade (FNB) versus adductor canal nerve blockade (ACB) for postoperative pain control and quadriceps muscle function in patients undergoing anterior cruciate ligament (ACL) reconstruction with patellar tendon autograft. A randomized therapeutic trial of 90 patients undergoing ACL reconstruction with patellar tendon autograft was conducted comparing ACB versus FNB at 24hours, 2 and 4 weeks, and 6months postsurgery. Early outcome measures included average pain score and morphine equivalent units (milligrams) consumed, quadriceps surface electromyography, straight leg raise, and ability to ambulate without assistive devices. The 6-month outcome measures included knee range of motion (ROM), isokinetic knee extension peak torque, single-leg squat, and single-leg hop performance. Complications were recorded throughout the study for the development of anterior knee pain, knee extension ROM loss, deep vein thrombosis, and graft failure. Mixed-model analysis of variance and Mann-Whitney U tests were performed using an alpha of .05. Quadriceps surface electromyography deficits were higher for FNB at 24hours (P < .001) and 2weeks (P < .001) when compared with the ACB group. There were no between-groups difference for subjective pain (P= .793) or morphine consumption (P= .358) within the first 24hours of surgery. A higher percentage of patients in the ACB group met the full ambulation criteria at 4weeks compared with the FNB group (100% vs 84.2%, P < .001). No between-group differences were observed at 6months; however, the rate of knee extension ROM loss was higher for the FNB group versus the ACB group (21.1% vs 5.0%, P= .026), respectively. ACB was as effective as FNB at providing pain control while eliciting fewer quadriceps muscle activation deficits and fewer postoperative complications. Based on previous evidence and the results of this study, we recommend the use of ACB over FNB for theanalgesic management of patients undergoing ACL reconstruction with patellar tendon autograft. Level I, prospective randomized controlled trial.

Reliability of quadriceps surface electromyography measurements is improved by two vs. single site recordings

PurposeThe reliability of surface electromyography (sEMG) is typically modest even with rigorous methods, and therefore further improvements in sEMG reliability are desirable. This study compared the between-session reliability (both within participant absolute reliability and between-participant relative reliability) of sEMG amplitude from single vs. average of two distinct recording sites, for individual muscle (IM) and whole quadriceps (WQ) measures during voluntary and evoked contractions.MethodsHealthy males (n = 20) performed unilateral isometric knee extension contractions: voluntary maximum and submaximum (60%), as well as evoked twitch contractions on two separate days. sEMG was recorded from two distinct sites on each superficial quadriceps muscle.ResultsAveraging two recording sites vs. using single site measures improved reliability for IM and WQ measurements during voluntary (16–26% reduction in within-participant coefficient of variation, CVW) and evoked contractions (40–56% reduction in CVW).ConclusionsFor sEMG measurements from large muscles, averaging the recording of two distinct sites is recommended as it improves within-participant reliability. This improved sensitivity has application to clinical and research measurement of sEMG amplitude.

Lumbar Radiculopathy Confounded: Total Knee Arthroplasty Diminishes the Patellar Tendon Reflex.

Patellar tendon reflexes were elicited among patients who had had a unilateral total knee replacement, those planned for unilateral total knee replacement, and a cohort of controlled patients. Patellar tendon reflex (PTR) response was measured with surface electromyography. The aim of this study was to determine if total knee arthroplasty significantly alters the PTR. As part of the clinical evaluation of the spine, extremity reflexes are provoked. Reflex variation between right and left extremities can be a pathological finding in disease of the spine. It has been noted that in patients who have undergone total knee arthroplasty (TKA), the PTR is diminished on the operative side compared with the contralateral nonoperative side. PTR is part of the clinical exam when evaluating a patient for lumbar radiculopathy. The right and left patellar tendon reflex intensities were measured by quadriceps surface electromyography in 3 groups of patients. Group 1 consisted of 21 patients with unilateral TKA who were at least 6 months postoperative. Group 2 consisted of 18 patients with unilateral severe knee arthritis indicated for TKA. Group 3, serving as the control group, included 20 patients with no evidence of knee arthritis in either knee. The average reflex response for each group was recorded and comparisons were then made between each group. Patients who have undergone unilateral TKA have a PTR on average of 55.1% of their contralateral uninvolved side. This is statistically significant when compared with reflexes in patients who are planned for unilateral total knee arthroplasty, 96.03% (P = 0.001) and when compared with patients without evidence for knee arthritis, 102.2% (P < 0.001). The results of this case control study show that TKAs do significantly diminish PTRs when compared with a contralateral uninvolved knee in the same patient. 3.

Effects of early application of Tuina treatment on quadriceps surface myoelectricity in patients after total knee arthroplasty: a randomized controlled trial

Total knee replacement surgery is commonly used in end-stage diseases of the knee. It is important for improving surgical efficacy and patient satisfaction by promoting early rehabilitation of patients and improving knee function. To observe the effects of early application of Tuina treatment on quadriceps surface electromyography (EMG) in patients with rheumatoid arthritis having undergone total knee arthroplasty. The study was performed at the Orthopedic Department of Huashan Hospital, Fudan University, and the Shanghai Guanghua Hospital of Integrated Traditional Chinese and Western Medicine from June 2010 to September 2011. A total of 66 patients with rheumatoid arthritis who had undergone total knee replacement surgery were randomly divided into control group and observation group, 33 cases in each. The patients in the control group were administered with continuous passive training (CPM), and the patients in the observation group were treated with CPM combined with Tuina, from prior surgery to four weeks post-surgery. The knee function was evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire at baseline and 4 weeks after the surgery. Quadriceps surface EMG was also detected at the same time points. After 4 weeks of Tuina and comprehensive rehabilitation intervention, the WOMAC questionnaire score of the observation group was decreased compared with the control group (P<0.01); median frequency and integrated electromyography of the rectus femoris and vastus medialis muscles, which were recorded by EMG, in the observation group were higher than those in the control group (P<0.01). Tuina can improve the recovery of patients who have undergone total knee replacement by increasing quadriceps EMG.

Mechanics of the Knee

The load moment of force about the knee joint during machine milking and when lifting a 12.8 kg box was quantified using a computerized static sagittal plane body model. Surface electromyography of quadriceps and hamstrings muscles was normalized and expressed as a percentage of an isometric maximum voluntary test contraction. Working with straight knees and the trunk flexed forwards induced extending knee load moments of maximum 55 Nm. Lifting the box with flexed knees gave flexing moments of 50 Nm at the beginning of the lift, irrespective of whether the burden was between or in front of the feet. During machine milking, a level difference between operator and cow of 0.70 m - 1.0 m significantly lowered the knee extending moments. To quantify the force magnitudes acting in the tibio-femoral and patello-femoral joints, a local biomechanical model of the knee was developed using a combination of cadaver knee dissections and lateral knee radiographs of healthy subjects. The moment arm of the knee extensor was significantly shorter for women than for men, which resulted in higher knee joint forces in women if the same moment was produced. A diagram for quantifying patellar forces was worked out. The force magnitudes given by the knee joint biomechanical model correlated well with experimentally forces measured by others. During the parallel squat in powerlifting, the maximum flexing knee load moment was estimated to 335-550 Nm when carrying a 382.5 kg burden and the in vivo force of a complete quadriceps tendon-muscle rupture to between 10,900 and 18,300 N. During isokinetic knee extension, the tibio-femoral compressive force reached peak magnitudes of 9 times body weight and the anteroposterior shear force was close to 1 body weight at knee angles straighter than 60 degrees, indicating that high forces stress the anterior cruciate ligament. A proximal resistance pad position decreased the shear force considerably, and this position is recommended in early rehabilitation after anterior cruciate ligament repairs or reconstructions. The methods presented quantify muscle activity, sagittal knee joint moments and forces, enabling assessments to be made of different work postures, training exercises and joint derangements.