Introduction: Mobile bearing total knee arthroplasty (TKA) has been developed to theoretically provide better, more physiological function of the knee and produce less PE wear. The theoretical superiority of mobile bearing TKAs over fixed bearing devices has not yet been proven in clinical studies. The objective of the present study was to prospectively analyze clinical and functional outcomes of randomized fixed and mobile bearing total knee arthroplasty patients by means of gait analysis, electromyography and established clinical scores. Methods: In a prospective, randomized, patient- and observer-blinded, clinical study, 33 patients (mean age 63 years) received a cruciate retaining Genesis II TKA for primary osteoarthritis. 16 patients received a mobile bearing and 17 patients a fixed bearing device. The day before surgery and 24 months postoperatively, established clinical (KSS, HSS, WOMAC, UCLA, VAS) and quality of life (SF-36) scores were used to compare both patient groups. Electromyography of standardized locations was measured with the MyoSystem 2000 and analyzed with Myoresearch software. Gait analysis was performed with a six camera motion analysis system and force platforms. Results: Both groups showed significant improvements between pre- and postoperative evaluation in gait analysis and electromyography, but gait analysis results as well electromyography did not show any difference between both groups at follow-up. Clinical and quality of life results significantly improved from pre- to postoperative evaluation, but only the Knee Society Score showed a significant superiority of the mobile bearing group (mean 159.0; SD 27.7; range, 105–196) over the fixed bearing group (mean 134.4; SD 41; range, 56–198) (p=0.0022). Conclusions: In the present study, no functional advantage of mobile bearing TKA over fixed bearing devices could be found, although the mobile bearing group had better clinical results. Thus, long-term clinical results and in-vivo wear analyses have to be followed, and more subtle functional analyses (e.g. fluoroscopy) have to be employed to finally judge over the theoretical advantage of mobile bearing TKAs

Abstract. Objectives. Total hip arthroplasty (THA) procedures are physically demanding for surgeons. Repetitive mallet swings to impact a surgical handle (impactions), can lead to muscle fatigue, discomfort and injuries. The use of an automated surgical hammer may reduce fatigue and increase surgical efficiency. The aim of this study was to develop a method to quantify user's performance, by recording surface electromyography (sEMG), for automated and manual impactions. Methods. sEMG signals were recorded from eight muscle compartments (arm and back muscles) of an orthopaedic surgeon during repetitions of manual and automated impaction tasks, replicating femoral canal preparation (broaching) during a THA. Each task was repeated, randomly, four times manually and four times with the automated impaction device. The mechanical outcomes (broaching efficiency and broach advancement) were quantified by tracking the kinematics of the surgical instrumentation. Root mean square (RMS) values and median frequency (MDF) were calculated for each task to, respectively, investigate which muscles were mostly involved (higher RMS) in each task and to quantify the decrease in MDF, which is an indicator of muscle fatigue. Results. RMS for arm muscles was significantly higher (p-value=0.002) during manual impactions than during automated impactions and muscle fatigue was significantly reduced (p-value=0.011), for the same muscles, when the same tasks were performed with the automated surgical hammer. The time required to achieve the same mechanical outcome, in terms of broaching efficiency and broach advancement, was significantly reduced with the automated surgical hammer (p=0.019). Conclusions. Results from this study showed how with this methodology it was possible to discern muscle performance and fatigue, between impaction modalities. Moreover, the reduction in exposure time to automated impactions, could be a factor in muscle fatigue decrease. These results could therefore provide useful insights into the study of surgical ergonomic improvements, to reduce surgeons muscle fatigue and, potentially, injuries. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Background:. Little validation has been done to compare the principle of using the contralateral side as compared to and age and gender matched control. This study seeks to assess the validity of using the contralateral shoulder as the control as opposed to an age- gender- matched control. This study will give insight as to whether the contralateral side is a viable control as compared to a normal age and gender matched control. The study showed that the use of the contralateral shoulder was not a viable normal control. Methods:. 50 subjects were recruited for an institutional review board approved study. We studied 33 subjects who were ≥ 6 months post unilateral RSTA and 17 subjects who comprised our normal age- and gender-matched control group. The activity of the contralateral shoulder for each RTSA subject was recorded. All subjects were prompted to elevate their arm to perform abduction, flexion, and external rotation activities in both weighted and un-weighted configurations. Electromyography activation of the anterior, lateral, and posterior aspects of the deltoid and the upper trapezius muscles were recorded bilaterally using bipolar surface electrodes. Motion capture using passive reflective markers was used to quantify three-dimensional motions of both shoulders. Results:. During abduction and flexion, deltoid and upper trapezius activity was significantly increased in RTSA contralateral shoulder as compared to age and gender matched control shoulders (Figure 1, 2, 3). Figure breakdown comprised of the anterior deltoid: Top left, lateral deltoid: top right, posterior deltoid: bottom left, upper trapezius: bottom right. The red line represents the contralateral shoulder for the RTSA subject while the black line represented the age- and gender- matched control. No differences were seen in the anterior and lateral deltoid activity between groups during un-external rotation. Conclusion:. Muscle activation of the deltoid and the upper trapezius muscle is significantly different in the contralateral shoulder of an RTSA than an age and gender matched control subject. The study suffers from the limitation of the muscle pathology for the contralateral shoulder. Some studies have shown that rotator cuff deficiency is a bilateral issue. All subjects were able to perform the functional tasks required and thereby met the requirements to participate in the study. Differences point to the notion that muscle deficiency in the RTSA subjects may be prevalent in both shoulders. It may also point to a slower rate of deficiency for the non-involved shoulder. The purpose of this study was to investigate whether the contralateral shoulder was a viable control. Significant differences were found between the RTSA contralateral shoulder and the age- and gender- matched control that show that the RTSA contralateral shoulder is not a viable control

The aim of this study was to validate the SENIAM recommendations for surface electromyography placement(sEMG) over rectus femoris(RF) muscle in healthy children and in children with cerebral palsy(CP) during gait analysis and compare placement using these guidelines to using ultrasonography. Methods & Results:. The study included 10 healthy children volunteers and 10 CP children volunteers, aged 8–12. All the CP children had spastic diplegia, were GMFCS levels I–II and had not previously undergone surgery. RF electrodes were placed following SENIAM recommendations. RF was then identified by ultrasound. The distance between the lateral edge of RF and the position of the sEMG electrode as per SENIAM guidelines and the width of RF was measured, to the nearest millimetre. We considered ‘ideal electrode’ position to be at halfway between the edges of RF (i.e. 50%). The mean percentage difference in distance from the ‘ideal electrode’ position as measured by ultrasound to electrode placement following SEMIAN guidelines was 2.7% in the healthy children group compared with 19.5% in the CP group. By performing unpaired t tests we showed that there was no significant difference between the mean electrode position using SEMIAN guidelines and ‘ideal electrode’ position in the healthy children (p=0.0531), however the mean electrode position using SEMIAN guidelines in the CP patients was significantly different from the ‘ideal electrode’ position (p=0.0001). Conclusion:. SENIAM recommendations for sEMG electrode placement over RF muscle were validated in 10 healthy children. We showed that ultrasonography improved the accuracy of sEMG electrode placement in children with CP, who can exhibit anatomical variation due to their condition. Accurate electrode placement will ensure that a more accurate signal is recorded which may have a direct clinical bearing on the decision to proceed with surgical intervention. Level of evidence: II

Purpose: Low frequency peaks (LFP) commonly observed in EMG spectra of paraspinal muscles. These peaks have frequency of 11–15Hz (Median=13, SD=4) and commonly observed in 40% of EMG recordings. We examined the correlation of these peaks with variation in within individuals change in load, between individuals load, gender, age, history of back pain and HW.

Methods and results: Nineteen healthy volunteers were recruited for study of within subject variation in load and data from 106 subjects was examined for the remaining analysis reported here. EMG acquisition was performed using the method described by Oliver et al (Oliver et al., 1996) at a range of load varying from a kilogram to 100% MVC in increments of 10% MVC. The tests were performed in a random order. This method was used for acquisition of data from the second group (n=106) with an exception that only one load fixed at 2/3MVC was used. All parameters including Low frequency peaks and Half Width (HW) was calculated by an automated software developed for this purpose

No correlation between within individual change in load and presence or absence of LFP was found. Only one subject showed a significant correlation between individual change in load with the magnitude of LFPs (r=−0.75, p=0.012). However, when the cumulative data from all 19 subjects was analysed, small correlation between the change in load and magnitude of LFPs (r=−0.17, n=187, p=0.022) was observed, with greater load associated with smaller LFP. No other correlation between gender, individuals load, age and fitness was found.

Conclusion: The appearance of the LFP has been previously described. As yet the underlying cause is not understood, but may be related to a load/feedback loop. The results of this study suggest that load is a factor that may affect LFP and this should be taken into consideration when methods such as HW are used.

Aim: To develop a database of the force generated by brachioradialis muscle (BR) using IEMG.

Methods: The 32 BR muscles of 12 young male and four young female adults were studied using the MedTronic functional diagnostics key point EMG machine. Two self adhesive surface electrodes were placed 3mm apart over the BR belly and a third earth electrode over the radial styloid process. The subject’s arm was at the side of the trunk, the elbow flexed to 90 degrees and the forearm strapped in neutral rotation. Recordings were taken over a five-second voluntary maximum isometric elbow flexion and the force of the contraction measured from the rectified and integrated tracing (mv.ms). Four recordings were taken for each arm; wrist in neutral and at maximum passive flexion, with a two-minute rest between recordings. Recordings were repeated after minimum of 24 hours later.

Results: There was large inter-subject variability with a range of values recorded between 14 685 and 278 533 mv.ms with an average of 99 472 for the wrist in neutral and 93 038 with the wrist flexed in males and 53 292 and 57 224 respectively for females. However, intra-subject variability was low (co-efficient of variation, CV 8 to 11%) and good repeatability (CV 6 to13%). There was no significant statistical difference with the wrist either in neutral or fully flexed.

Conclusions: BR is the key muscle for hand reconstruction in tetraplegia but it has not been possible until now to test its force objectively in isolation from other elbow flexors. Although the results from the study demonstrated a wide range of values for the BR muscle the consistent repeatability probably reflected different involvement of the BR muscle in elbow flexion. If verified, it would indicate that tetraplegics who have low IEMG values should benefit from specific strengthening exercises prior to transfer surgery.

We present the use of dynamic electromyographic analysis (DEMG) in the diagnosis of muscle patterning instability. DEMG’s were requested in 168 of 562 muscle patterning shoulders with suspected subclinical or clinically complex muscle patterning instability. An experienced neurophysiologist (blinded to the clinical findings and direction of instability) inserted dual-wire tungsten electrodes into pectoralis major, latissimus dorsi, infraspinatus and anterior deltoid. Muscle activity was recorded during rest, flexion, abduction, extension, and cross-body adduction. 5 investigations were abandoned. The timing and magnitude of muscle activity was noted and compared to the clinical diagnosis and direction of instability. DEMG identified a total of 204 abnormal muscle patterns in 163 shoulders. The examination was normal in 13 patients (8%). A single muscle was abnormal in 63 shoulders, 2 muscles in 55, 3 muscles in 9, and all 4 muscles in one shoulder. Over-activation of pectoralis major was identified in 58%, and latissimus dorsi in 70%, of shoulders with anterior instability. In posterior instability, latissimus dorsi was overactive in 76%, anterior deltoid in 14% and infraspinatus was under-active in 24%. Pectoralis major and Latissimus dorsi were both overactive in 38% of anterior, 29% of posterior and 38% of multidirectional instability. Abnormal muscle patterns were identified in 52 shoulders with subclinical muscle patterning. A further 98 shoulders had 134 clinically abnormal muscle patterns. These were confirmed by DEMG in 57 cases (sensitivity 43%), and DEMG’s were normal in 77 (specificity 43%). DEMG also identified 65 additional muscles as abnormal in the 98 clinically abnormal shoulders. DEMG performed by an experienced neurophysiologist provides additional information regarding abnormal muscle activation in selected complex or subtle cases of muscle patterning instability in which clinical examination has a low sensitivity and specificity.

The shoulder girdle is an extremely mobile joint. Rotator cuff tears alter the existing equilibrium between bony structures and muscles. The “subacromial impingement syndrome” resulting from this unbalance leads to an extension of the rotator cuff lesion.

Many authors have postulated a “mechanism of compensation”, but its existence still requires evidence. According to this model, the longitudinal muscles of the shoulder and the undamaged muscles of the rotator cuff would be able to functionally compensate, supersede the function of rotator cuff, and reduce symptoms.

The aim of this study was to evaluate muscular activation of the medium fibers of deltoid, the superior fibers of pectoralis major, the latissimus dorsi and the infraspinatus by a superficial electromyographic study (EMG) and the analysis of kinematics in patients with a massive rotator cuff tear.

We evaluated 30 subjects: 15 had pauci-symptomatic massive rotator cuff tear (modest pain and preserved movement), and 15 were healthy controls.

Paired t-test showed significant different activations (p< 0.05) of these 4 muscles between the pathological joint and the healthy one in the same patient.

The unpaired t-test, after comparing the mean EMG values of the 4 muscles, produced a significant difference (p< 0.05) between the experimental group and control group.

This study showed that a mechanism of muscular compensation is activated in patients suffering from rotator cuff tear, involving the deltoid and the infra-spinatus muscle, as already presented in literature, but also demonstrated the activation of 2 other muscles: the latissimus dorsi and the pectoralis major. It is, therefore, probable that, in these patients, these muscles, which would not normally pull the head of the humerus downwards, adapt in order to compensate for the pathological situation. We believe that these data are valuable in the surgical and rehabilitation planning in patients with a massive rotator cuff tear.

Poor trunk extensor endurance is implicated in low back pain; less, however, is known about contributions of left and right sides and upper and lower parts to maximum torque production following fatigue. This study examines torque and electromyographic (EMG) activity in different parts of the left and right trunk extensors before and following a maximal voluntary contraction (MVC) hold.

16 student rowers participated and written informed consent was obtained. Testing was performed in a Cybex isokinetic dynamometer with synchronous bilateral EMG recordings (during brief MVCs) from the left and right the erector spinae (ES) muscles at vertebral levels T12 and L4, prior to and immediately after, and 1, 5 and 10 minutes after a 60 second MVC.

A small decrease in maximum torque was observed during 60s MVC, followed by a non significant step-wise increase. The torque at 10 minutes post MVC was the highest value recorded. EMG activity rose in the right upper back 5 and 10 mins following the fatigue. Furthermore, the ratios of left:right EMG activity revealed an increase compared to pre-fatigue values in the lower back but a decrease in the upper back, suggesting the task involved differential use of left and right sides in addition to upper and lower back muscles.

These results suggest that 60s MVC induces differential activation of left and right sides and upper and lower parts of the trunk extensors. The apparent potentiation in force and asymmetry of activation following the 60s MVC task requires further investigation.

Abstract. Source of Study: London, United Kingdom. This intervention study was conducted to assess two developing protocols for quadriceps and hamstring rehabilitation: Blood Flow Restriction (BFR) and Neuromuscular Electrical Stimulation Training (NMES). BFR involves the application of an external compression cuff to the proximal thigh. In NMES training a portable electrical stimulation unit is connected to the limb via 4 electrodes. In both training modalities, following device application, a standardised set of exercises were performed by all participants. BFR and NMES have been developed to assist with rehabilitation following lower limb trauma and surgery. They offer an alternative for individuals who are unable to tolerate the high mechanical stresses associated with traditional rehabilitation programmes. The use of BFR and NMES in this study was compared across a total of 20 participants. Following allocation into one of the training programmes, the individuals completed training programmes across a 4-week period. Post-intervention outcomes were assessed using Surface Electromyography (EMG) which recorded EMG amplitude values for the following muscles: Vastus Medialis, Vastus Lateralis, Rectus Femoris and Semitendinosus. Increased Semitendinosus muscle activation was observed post intervention in both BFR and NMES training groups. Statistically significant differences between the two groups was not identified. Larger scale randomised-controlled trials are recommended to further assess for possible treatment effects in these promising training modalities

Few surgical techniques to reconstruct the abductor mechanism of the hip have been reported, with outcomes reported only from case reports and small case series from the centres that described the techniques. As in many of our revision THA patients the gluteus maximus was affected by previous repeat posterior approaches, we opted to reconstruct the abductor mechanism using a vastus lateralis to gluteus medius transfer. We report the results of such reconstructions in seven patients, mean age 66 (range, 53–77), five females, presenting with severe abductor deficiency (MRC grade 1–2). Five patients had previous revision THA, two with a proximal femoral replacement, one patient had a primary THA after a failed malunited trochanteric fracture, and one patient had a native hip with idiopathic fatty infiltration of glutei of >90%. All patients had instrumented gait analysis, and surface electromyography (EMG) of the glutei, TFL, and vastus muscles simultaneously before surgery and at each post-op follow-up. Postoperatively, patients were allowed to weight bear as tolerated and were requested to wear an abduction brace for the first six weeks after surgery to protect the transfer. All patients improved after surgery and reached an abductor power of 3 or more. All patients walked without support six months after surgery and were satisfied with the result. Abductor function continued to improve beyond one year of follow-up, and some patients reached an abductor power of 5. EMG demonstrated that the transferred vastus lateralis started firing synchronously with gluteus medius after three months post-surgery, suggesting adaptation to its new function. No knee extension weakness was recorded. One patient complained of lateral thigh numbness and was dissatisfied with the cosmetic look of her thigh after surgery. Our preliminary results are encouraging and comparable with those achieved by the originators of the technique

Mechanical loading of joints with osteoarthritis (OA) results in pain-related functional impairment, altered joint mechanics and physiological nociceptor interactions leading to an experience of pain. However, the current tools to measure this are largely patient reported subjective impressions of a nociceptive impact. A direct measure of nociception may offer a more objective indicator. Specifically, movement-induced physiological responses to nociception may offer a useful way to monitor knee OA. In this study, we gathered preliminary data on healthy volunteers to analyse whether integrated biomechanical and physiological sensor datasets could display linked and quantifiable information to a nociceptive stimulus. Following ethical approval, 15 healthy volunteers completed 5 movement and stationary activities in 2 conditions; a control setting and then repeated with an applied quantified thermal pain stimulus to their right knee. An inertial measurement unit (IMU) and an electromyography (EMG) lower body marker set were tested and integrated with ground reaction force (GRF) data collection. Galvanic skin response electrodes for skin temperature and conductivity and photoplethysmography (PPG) sensors were manually timestamped to the integrated system. Pilot data showed EMG, GRF and IMU fluctuations within 0.5 seconds of each other in response to a thermal trigger. Preliminary analysis on the 15 participants tested has shown skin conductance, PPG, EMG, GRFs, joint angles and kinematics with varying increases and fluctuations during the thermal condition in comparison to the control condition. Preliminary results suggest physiological and biomechanical data outputs can be linked and identified in response to a defined nociceptive stimulus. Study data is currently founded on healthy volunteers as a proof-of-concept. Further exploratory statistical and sensor readout pattern analysis, alongside early and late-stage OA patient data collection, can provide the information for potential development of wearable nociceptive sensors to measure disease progression and treatment effectiveness

Background. Previous work has identified differential kinematics and muscle activity between non-specific chronic low back pain (LBP) subgroups (flexion pattern (FP) and active extension pattern) and healthy controls. However, it is unclear if differences in muscle activity are maintained on resolution of pain and/or if they contribute to pain recurrence. Purpose. To investigate differences in trunk muscle activity between individuals with a history of flexion-related LBP (who are currently pain-free) and no-LBP controls during three functional activities. Methods. Fifteen individuals (10 male, 5 female) with a previous history of FP LBP (but who were currently pain-free) and 15 individuals with no history of low back pain (10 male, 5 female) were recruited. Surface electromyography of bilateral superficial lumbar multifidus, longissimus thoracis, transversus abdominus/internal oblique and external oblique muscle activity was recorded during three functional activities (sit-to-stand, step-up and bending to pick up a pen from the floor). Surface electromyography data was normalised (% maximum voluntary contraction) and compared between groups (Mann-Whitney U test). Results. No significant differences were observed for any muscle in any activity (p>0.05) except for significantly increased right superficial lumbar multifidus during the bending task (p=0.04) in the FP group compared to the control group (36.55 vs. 19.97 respectively). Conclusion. Individuals with resolved FP LBP have similar trunk muscle activation to those with no history of LBP. This suggests that muscle activity behaviours may ‘normalise’ in FP on resolution of pain. Further work should explore muscle activity during recurrent episodes to establish links with pain provocation. No conflicts of interest. No funding obtained

Background. Trunk muscle activity and thoraco-lumbar kinematics have been shown to discriminate non-specific chronic low back pain (NSCLBP) subgroups from healthy controls. Thoracic spine kinematics and muscle activity whilst intuitively associated with NSCLBP, has received less attention and the possibility of intra-regional interactions remains an area for exploration. Purpose. Determine relationships between muscle activation and kinematics in active extension pattern (AEP) and flexion pattern (FP) subgroups and no-low back pain controls during a sagittal bending task. Methods. Fifty NSCLBP subjects (27 FP, 23 AEP) and 28 healthy controls underwent 3D motion analysis (Vicon™) and surface electromyography whilst bending to retrieve a pen from the floor. Mean sagittal angle for the upper and lower thoracic and lumbar regions (UTx, LTx, ULx, LLx) were compared with normalised mean amplitude electromyography of 4 bilateral trunk muscles. Pearson correlations were computed to assess relationships. Results. Significant relationships between lumbar multifidus and ULx/LLx were identified in AEP during bending and return (p<0.01). FP exhibited multiple significant interactions including between longissimus thoracis and lumbar multifidus and LLx/LTx (p<0.035); and external oblique activity and UTx/LTx (p<0.05) during bending and return (and LLx during bending). Correlations were moderate to strong (r= −0.812 to 0.664). Conclusion. Kinematic and trunk muscle activity measurements differentiated between NSCLBP sub-groups and controls, especially between LLx kinematics and lumbar multifidus activity. Contrasting muscle activation patterns between LLx and LTx regions in FP highlights the importance of regional thoracic measurements, and suggests likely compensation strategies. Replication during other tasks should be evaluated in future studies. No conflicts of interest. Funding provided by Versus Arthritis (Formerly Arthritis Research UK)

Abstract. Objectives. Current tools to measure pain are broadly subjective impressions of the impact of the nociceptive impulse felt by the patient. A direct measure of nociception may offer a more objective indicator. Specifically, movement-induced physiological responses to nociception may offer a useful way to monitor knee OA. In this proof-of-concept study, we evaluated whether integrated biomechanical and physiological sensor datasets could display linked and quantifiable information to a nociceptive stimulus. Method. Following ethical approval, we applied a quantified thermal pain stimulus to a volunteer during stationary standing in a gait lab setting. An inertial measurement unit (IMU) and an electromyography (EMG) lower body marker set were tested and integrated with ground reaction force (GRF) data collection. Galvanic skin response electrodes and skin thermal sensors were manually timestamp linked to the integrated system. Results. The integrated EMG, GRF and IMU data show fluctuations within 0.5 seconds of each other when a thermal pain trigger is applied at several time points during a stationary standing test. Manually timestamped physiology measures displayed increased values during testing for skin conductivity (up to 5 µSiemens, 37% compared to baseline) and skin temperature (up to 0.3˚C, 1% compared to baseline). Conclusions. This proof-of-concept study suggests that physiological data mimics biomechanical data in response to a known pain stimuli. While this protocol requires further evaluation as to the measurement parameters, the association of the physiological output to the known pain stimulus suggests the potential development of wearable nociceptive sensors that can measure disease progression and treatment effectiveness

Objectives. The aim of this study was to investigate the biomechanical effect of the anterolateral ligament (ALL), anterior cruciate ligament (ACL), or both ALL and ACL on kinematics under dynamic loading conditions using dynamic simulation subject-specific knee models. Methods. Five subject-specific musculoskeletal models were validated with computationally predicted muscle activation, electromyography data, and previous experimental data to analyze effects of the ALL and ACL on knee kinematics under gait and squat loading conditions. Results. Anterior translation (AT) significantly increased with deficiency of the ACL, ALL, or both structures under gait cycle loading. Internal rotation (IR) significantly increased with deficiency of both the ACL and ALL under gait and squat loading conditions. However, the deficiency of ALL was not significant in the increase of AT, but it was significant in the increase of IR under the squat loading condition. Conclusion. The results of this study confirm that the ALL is an important lateral knee structure for knee joint stability. The ALL is a secondary stabilizer relative to the ACL under simulated gait and squat loading conditions. Cite this article: Bone Joint Res 2019;8:509–517

Introduction and Objective. Medial Knee Osteoarthritis (MKO) is associated with abnormal knee varism, this resulting in altered locomotion and abnormal loading at tibio-femoral condylar contacts. To prevent end-stage MKO, medial compartment decompression is selectively considered and, when required, executed via High Tibial Osteotomy (HTO). This is expected to restore normal knee alignment, load distribution and locomotion. In biomechanics, HTO efficacy may be investigated by a thorough analysis of the ground reaction forces (GRF), whose orientation with respect to patient-specific knee morphology should reflect knee misalignment. Although multi-instrumental assessments are feasible, a customized combination of medical imaging and gait analysis (GA), including GRF data, rarely is considered. The aim of this study was to report an original methodology merging Computed-Tomography (CT) with GA and GFR data in order to depict a realistic patient-specific representation of the knee loading status during motion before and after HTO. Materials and Methods. 25 MKO-affected patients were selected for HTO. All patients received pre-operative clinical scoring, and radiological/instrumental assessments; so far, these were also executed post-operatively at 6-month follow-up on 7 of these patients. State-of-the-art GA was performed during walking and more demanding motor tasks, like squatting, stair-climbing/descending, and chair-rising/sitting. An 8-camera motion capture system, combined with wireless electromyography, and force platforms for GRF tracking, was used together with an own established protocol. This marker-set was enlarged with 4 additional skin-based non-collinear markers, attached around the tibial-plateau rim. While still wearing these markers, all analyzed patients received full lower-limb X-ray in standing posture a CT scan of the knee in weight-bearing Subsequently, relevant DICOMs were segmented to reconstruct the morphological models of the proximal tibia and the additional reference markers, for a robust anatomical reference frame to be defined on the tibia. These marker trajectories during motion were then registered to the corresponding from CT-based 3D reconstruction. Relevant registration matrices then were used to report GRF data on the reconstructed tibial model. Intersection paths of GRF vectors with respect to the tibial-plateau plane were calculated, together with their centroids. Results. Pre-operative clinical and radiological scoring confirmed MKO and associated abnormal varism. The morphological characterization of GRF was successfully achieved pre- and post- HTO on patient-specific tibial plateau. Pre-operative GFR patterns and peaks, including those related to knee joint moments, were observed medially on the knee, as expected. In post-HTO, these resulted lateralized and much closer to the tibial plateau spine, as desired. In detail, when post- is compared to pre-op, the difference of the centroids were, on average, 54.6±18.1 mm (min÷max: 36.7÷72.8 mm) more lateral during walking and 52.5±28.5 mm (24.7÷87.6 mm) during stair climbing. When reported in % of the tibial plateau width, these values became 69.2±20.1 (46.1÷81.4) and 78.1±30.1 (43.4÷98.0), respectively. Post-op also clinical scores and GA revealed a considerable overall improvement, especially in functional performances. Conclusions. The reported novel approach allows a combination of motion data, including GFR, and tibial-plateau morphology. Relevant pre- and post-operative routine application offer a quantification of the effect of the original deformity and executed joint realignment, and an assistance for surgical planning in case of HTO as well as ideally in other orthopedic treatments

Introduction and Objective. Carpal tunnel syndrome (CTS) is a very common compressive neuropathy involving the median nerve. The typical symptoms are paraesthesia, dysesthesia and loss of strength; in severe case, this compression deteriorates the sensorimotor control of the hand and interferes with the adjustment of the forces at the level of the fingers, thus affecting the components that are the basis of dexterity and control of fine movements. For these reasons, the CTS has repercussions on various activities of daily life, including writing skills. Word processing via PC and mobile device (touch-typing) require a fine control of the hand-wrist movement and of the opposition of the thumb, while in handwriting, gripping and gripping movements are carried out in a protracted manner. In modern society, present skills play a role of fundamental importance from an educational, professional and social point of view. The aim of the study is to describe the effects of carpal tunnel release (CTR) on handwriting and digital writing performance. Materials and Methods. We recruited patients suffering from carpal tunnel syndrome (CTS) who were candidates for CTR surgery and collected clinical and demographic data, including age, occupation, duration of symptoms and electromyography outcomes. The first trial session was carried out before surgery and the subsequent ones at 1, 2, 3, 4, 8 and 12 weeks after the CTR. These trials involved copying a 500-character paragraph by handwriting, personal computer (PC) and mobile device, for which a dedicate Google Colab web page was computed. We used as parameters the speed, expressed in words per minute (wpm), and the accuracy of copying, which was measured in number of errors (en). Moreover in each session the patient filled in the QuickDASH (Disabilities of the Arm, Shoulder, and Hand) questionnaire. We used the one-way anova to evaluate the change in the three performances and in the QuickDASH score in follow-up sessions. We used the two-way anova to detect a possible interactions between speed improvement and groups of variables, namely gender, writing frequency, schooling, diabetes, dysthyroidism and metabolic syndrome. Results. We recruited 20 patients of whom 7 dropped out for personal reasons and 13 had completed all trial sessions. The PC writing performance had an average speed and accuracy of 15.1 ± 6.8 wpm and 13.1 ± 8.2 en, respectively, while post-operatively it returned values of 17.6 ± 5.0 wpm and 9.9 ± 5.6 en. Regarding touch-typing, a pre-operative average of 16.9 ± 5.8 wpm and 14.3 ± 14.4 en was recorded, while post-operatively an average of 21.7 ± 6.5 wpm and 11.5 ± 14.7 en was reported. Handwriting performance initially had a mean of 20.5 ± 7.1 wpm and 0.1 ± 0.6 en and after three months returned a mean of 22.4 ± 4.0 wpm and 0 ± 0 n. The QuickDASH score had a pre-operative mean of 39.1 ± 9.1 and post-operative mean of 17 ± 6 points. The only statistically significant improvements were those related to touch-typing (P = 0.022) and QuickDASH score (P < 0.001). There was no significant interaction between gender, comorbidity, writing frequency, level of schooling and recovery of writing ability. Conclusions. The data collected showed, in agreement with previous studies, that CTS has a significant impact on the patient's writing ability, who benefits from the surgical treatment, especially in terms of touch-typing and general manual dexterity. In addition, the recovery of writing ability did not show significant correlation with other variables

Aim of the Study: Evaluation of differences in pro-prioception, gait analysis, electromyography in consideration of clinical results in patients with unicondylar and bicondylar knee arthroplasty. Material and Methods: 17 patients with mean age of 62.5 years were examined after a mean time of 21.5 months after unicondylar knee arthroplasty and compared with 15 patients with a mean age of 67 years and a mean time of 31.9 months after bicondylar knee arthroplasty. For clinical examination the Knee Society, Hospital for Special Surgery and Patella Score were used. Proprioception was examined using the Balance test. In addition each patient was examined by gait analysis with three-dimensional-kinematics and force plate. M. rectus femoris, M. vastus medialis/lateralis, M. semiten-dinosus, M. biceps femoris, M. tibialis anterior and M. gastrocnemius were examined by electromyography. Results: There were neither significant deviations in demographic data, clinical scores, electromyography results (except M. vastus lateralis), gait analysis nor in proprioception. Conclusion: There were no deviations in any clinical or functional results in patients with unicondylar and bicon-dylar knee arthroplasty. Because of the uncertain long term results of unicondylar knee arthroplasty in respect of loosening and development of contralateral osteoarthritis, bicondylar knee arthroplasty can be approved

Surgeries for reverse total shoulder arthroplasty (RTSA) significantly increased in the last ten years. Initially developed to treat patients with cuff tear arthropathy (CTA) and pseudoparalysis, wider indications for RTSA were described, especially complex proximal humerus fractures. We previously demonstrated in patients with CTA a different sequence of muscular activation than in normal shoulder, with a decrease in deltoid activation, a significant increase of upper trapezius activation and slight utility of the latissimus dorsi. There is no biomechanical study describing the muscular activity in patients with RTSA for fractures. The aim of this work is to describe the in vivo action of RTSA in patients with complex fractures of the proximal humerus. We conducted an observational prospective cohort study comparing 9 patients with RTSA for complex humerus fracture (surgery more than 6 months, healed tuberosities and rehabilitation process achieved) and 10 controls with normal shoulder function. Assessment consisted in a synchronized analysis of range of motion (ROM) and muscular activity on electromyography (EMG) with the use of 7 bipolar cutaneous electrodes, 38 reflective markers and 8 motion-recording cameras. Electromyographic results were standardized and presented in muscular activity (RMS) adjusted with maximal isometric contractions according to the direction tested. Five basic movements were evaluated (flexion, abduction, neutral external rotation, external rotation in 90° of abduction and internal rotation in 90° of abduction). Student t-test were used for comparative descriptive analysis (p < 0,05). The overall range of motion with RTSA is very good, but lower than the control group: flexion 155.6 ± 10 vs 172.2 ± 13.9, p<0.05, external rotation at 90° 55.6 ± 25 vs 85.6 ± 8.8, p<0,05, internal rotation at 90° 37.8 ± 15.6 vs 52.2 ± 12, p<0,05. The three heads of the deltoid are more stressed during flexion and abduction in the RTSA group (p. The increased use of the 3 deltoid chiefs does not support the hypothesis proposed by Grammont when the RTSA is performed for a complex proximal humerus fracture. This can be explained by the reduced dispalcement of the rotation center of the shoulder in these patients compared to those with CTA. These patients also didn't present shoulder stiffness before the fracture. The maximal muscle activity of the trapezius in flexion and of the latissimus dorsi in flexion and abduction had not been described to date. These new findings will help develop better targeted rehabilitation programs. In addition, the significant role of the latissimus dorsi must question the risks of its transfer (L'Episcopo procedure) to compensate for external rotation deficits