Comprehensive procedure for injecting Evusheld® for hematological diseases in a single institute.

Tixagevimab and cilgavimab (EVA, Evusheld®), monoclonal antibody combination treatments, consisted of two neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). EVA showed prophylactic and therapeutic effects against coronavirus disease 2019. The Japanese Society of Hematology recommended EVA for such patients with active treatment, but each institution decided on comprehensive administration. We develop a systematic procedure for comprehensive EVA injection prophylactically in patients with hematological malignancies without any over/under-indication. We listed all patients with the required indications from November 2022 to March 2023. We included 178 cases, 84 females and 94 males, with a median age of 70 (range: 19-90) years. Underlying diseases are myeloid neoplasms in 36 (20%), lymphoid neoplasms in 75 (73%), and others. Indications were intensively hematological malignancy treatment, rituximab treatment within 12 months, burton kinase inhibitor treatment, after chimeric antigen receptor T cell immunotherapy, and after stem cell transplantation in 74 (41%), 73 (41%), 3 (2%), 5 (3%), and 23 (13%) cases, respectively. Of the 178 cases, 22 (12.4%) refused EVA injection. Further, 42 and 136 cases were administered outpatient and inpatient, respectively. Over 95% of the listed cases received EVA injection within 3 months. No severe toxicities were observed among them (N = 156), and 8 (5.2%) cases had breakthrough SARS-CoV-2 infection, which was significantly lower (P = 0.02) than those without EVA (4 [18.2%] of 22 cases). Both groups showed no moderate or severe infection cases. This single-center experience showed that comprehensive EVA injection management effectively generated safer completion with preferable clinical impact.

Estimation of Vertical Ground Reaction Force during Single-leg Landing Using Two-dimensional Video Images and Pose Estimation Artificial Intelligence.

OBJECTIVE: Assessment of the vertical ground reaction force (VGRF) during landing tasks is crucial for physical therapy in sports. The purpose of this study was to determine whether the VGRF during a single-leg landing can be estimated from a two-dimensional (2D) video image and pose estimation artificial intelligence (AI). METHODS: Eighteen healthy male participants (age: 23.0 ± 1.6 years) performed a single-leg landing task from a 30-cm height. The VGRF was measured using a force plate and estimated using center of mass (COM) position data from a 2D video image with pose estimation AI (2D-AI) and three-dimensional optical motion capture (3D-Mocap). The measured and estimated peak VGRFs were compared using a paired t-test and Pearson's correlation coefficient. The absolute errors of the peak VGRF were also compared between the two estimations. RESULTS: No significant difference in the peak VGRF was found between the force plate measured VGRF and the 2D-AI or 3D-Mocap estimated VGRF (force plate: 3.37 ± 0.42 body weight [BW], 2D-AI: 3.32 ± 0.42 BW, 3D-Mocap: 3.50 ± 0.42 BW). There was no significant difference in the absolute error of the peak VGRF between the 2D-AI and 3D-Mocap estimations (2D-AI: 0.20 ± 0.16 BW, 3D-Mocap: 0.13 ± 0.09 BW, P = 0.163). The measured peak VGRF was significantly correlated with the estimated peak by 2D-AI (R = 0.835, P <0.001). CONCLUSION: The results of this study indicate that peak VGRF estimation using 2D video images and pose estimation AI is useful for the clinical assessment of single-leg landing.

Relationship between onset of trunk muscle activities and pelvic kinematics in individuals with and without chronic low back pain.

BACKGROUND: Lumbopelvic movement patterns during prone hip extension has been proposed as a clinical screening method for trunk muscle dysfunction in patients with chronic low back pain (CLBP). However, correlations between trunk muscle onset and pelvic kinematics have not been investigated. OBJECTIVE: To examine the correlation between trunk muscle onset and pelvic kinematics during prone hip extension in participants with CLBP. METHODS: Fifteen patients with CLBP and 15 healthy individuals participated. We evaluated the muscle activities of the lumbar multifidus, the longissimus, and the semitendinosus via electromyogram and the displacement angles of the pelvic tilt, oblique and rotation. RESULTS: The onset of the multifidus at the ipsilateral side of hip extension was significantly delayed in the patients with CLBP compared to the control group (P< 0.001). The onset of the ipsilateral multifidus in the control group was significantly correlated with increased anterior pelvic tilt angle (P= 0.019, r= 0.597), whereas no significant correlation was observed in the CLBP group (P= 0.810, r=-0.068). CONCLUSION: The results suggest that pelvic kinematics during prone hip extension does not predict the delayed trunk muscle onset in patients with CLBP.

The Difference in the Assessment of Knee Extension/Flexion Angles during Gait between Two Calibration Methods for Wearable Goniometer Sensors.

Frontal and axial knee motion can affect the accuracy of the knee extension/flexion motion measurement using a wearable goniometer. The purpose of this study was to test the hypothesis that calibrating the goniometer on an individual's body would reduce errors in knee flexion angle during gait, compared to bench calibration. Ten young adults (23.2 ± 1.3 years) were enrolled. Knee flexion angles during gait were simultaneously assessed using a wearable goniometer sensor and an optical three-dimensional motion analysis system, and the absolute error (AE) between the two methods was calculated. The mean AE across a gait cycle was 2.4° (0.5°) for the on-body calibration, and the AE was acceptable (<5°) throughout a gait cycle (range: 1.5-3.8°). The mean AE for the on-bench calibration was 4.9° (3.4°) (range: 1.9-13.6°). Statistical parametric mapping (SPM) analysis revealed that the AE of the on-body calibration was significantly smaller than that of the on-bench calibration during 67-82% of the gait cycle. The results indicated that the on-body calibration of a goniometer sensor had acceptable and better validity compared to the on-bench calibration, especially for the swing phase of gait.

The relationship between joint kinematic patterns during single-leg drop landing and perceived instability in individuals with chronic ankle instability.

BACKGROUND: Perceived instability is a primary symptom among individuals with chronic ankle instability. However, the relationship between joint kinematics during landing remains unclear. Therefore, we investigated the relationships between landing kinematics and perceived instability in individuals with chronic ankle instability. METHODS: In 32 individuals with chronic ankle instability, we recorded ankle, knee, and hip joint angles during a single-leg drop landing. Joint angle waveforms during 200 ms before and after initial contact were summarized into single values using two methods: peak joint angles and principal component scores via principal component analysis. Using Spearman's rank correlation coefficient (ρ), we examined the relationships of peak joint angles and principal component scores with the Cumberland Ankle Instability Tool score, with a lower score indicating a greater perceived instability (α = 0.05). FINDINGS: The second principal component scores of ankle angle in the horizontal and sagittal planes significantly correlated with the Cumberland Ankle Instability Tool score (Horizontal: ρ = 0.507, P = 0.003; Sagittal: ρ = -0.359, P = 0.044). These scores indicated the differences in the magnitude of angles before and after landing. Significant correlations indicated a greater perceived instability correlated with smaller internal rotation and plantarflexion before landing and smaller external rotation and dorsiflexion after landing. In contrast, no peak joint angles correlated with the Cumberland Ankle Instability Tool score (P > 0.05). INTERPRETATION: In individuals with chronic ankle instability, ankle movements during landing associated with perceived instability may be a protective strategy before landing and potentially cause ankle instability after landing.

Graft-versus-host disease after autologous stem cell transplantation in a recipient who underwent allogeneic stem cell transplantation 20 years earlier.

A literature review does not provide information about the safety of autologous hematopoietic stem cell transplantation (HSCT) in a recipient who has previously received allogeneic HSCT. We treated a 69-year-old woman with diffuse large B cell lymphoma. The patient received autologous stem cell transplantation (ASCT) in the second complete remission of malignant lymphoma. The patient had undergone allogeneic hematopoietic SCT (allo-HSCT) for chronic myeloid leukemia 20 years ago. Chronic myeloid leukemia had been in complete remission for the previous 20 years. Thus, the patient received autologous and allogenic HSCT 20 years apart. ASCT involves the patient receiving "self" hematopoietic cells from an allogeneic donor. In other words, this is immunologically the second allo-HSCT. The allo-HSCT 20 years ago was undergone by a related healthy brother, a human leukocyte antigen (HLA) 8/8 full matched donor. The conditioning regimen was reduced-intensity consisting of fludarabine and busulfan. The patient did not experience acute or chronic graft-versus-host disease (GVHD) after allo-HSCT. The second transplantation, ASCT was performed to the MEAM conditioning regimen. Engraftment was uneventful, and complete donor chimerism had been achieved even after ASCT. She suffered from an acute gastric mucosal lesion 52 days after ASCT. Pathological finding of gastric mucosa was nonspecific acute gastritis with significant neutrophil infiltration. Sex chromosome analysis of gastric mucosa demonstrated that mucosal cells had XX signals, whereas infiltrating neutrophils had XY signals. We speculated the patient onset of an acute gastric GVHD in this recipient after the second transplantation. This case remarked infiltration of neutrophils triggered GVHD reaction by resetting allogeneic immune reaction after the second transplantation. We describe a rare occurrence of GVHD reaction in a recipient of ASCT following allo-HSCT.

Clinical effects of tacrolimus blood concentrations early after allogeneic hematopoietic stem cell transplantation.

BACKGROUND AIMS: Tacrolimus (TAC) plus short-term methotrexate (stMTX) is used for graft-versus-host disease (GVHD) prophylaxis after allogeneic hematopoietic stem cell transplantation (allo-HSCT). TAC blood concentrations are frequently adjusted to enhance the graft-versus-leukemia/lymphoma effect or attenuate severe GVHD. Limited information is available on the clinical impact of these adjustments and the optimal time to perform them in order to achieve good clinical outcomes. METHODS: We retrospectively analyzed 211 patients who underwent allo-HSCT at our institutes. RESULTS: Higher TAC concentrations in week 3 correlated with a significantly higher cumulative incidence of relapse (CIR) (P = 0.03) and lower nonrelapse mortality (P = 0.04). The clinical impact of high TAC concentrations in week 3 on CIR was detected in the refined disease risk index: low/intermediate (P = 0.04) and high (P < 0.01), and conditioning regimens other than cyclophosphamide/total body irradiation and busulfan/cyclophosphamide (P = 0.07). Higher TAC concentrations in week 1 correlated with a lower grade 2-4 acute GVHD rate (P = 0.01). Higher TAC concentrations in weeks 2 and 3 correlated with slightly lower (P = 0.05) and significantly lower (P = 0.02) grade 3-4 acute GVHD rates, respectively. Higher TAC concentrations in weeks 1 and 3 were beneficial for severe acute GVHD in patients with a human leukocyte antigen-matched donor (P = 0.03 and P < 0.01, respectively), not treated with anti-thymocyte globulin (P = 0.02 and P = 0.02, respectively), and receiving three stMTX doses (P = 0.03 and P = 0.02, respectively). CONCLUSIONS: The clinical impact of TAC concentrations varied according to patient characteristics, including disease malignancy, conditioning regimens, donor sources, and GVHD prophylaxis. These results suggest that TAC management needs to be based on patient profiles.

Trunk Muscle Activity and Ratio of Local Muscle to Global Muscle Activity during Supine Bridge Exercises under Unstable Conditions in Young Participants with and without Chronic Low Back Pain.

Core exercises on an unstable surface increase trunk muscle activity, especially for local muscle groups. Therefore, there is a possibility that exercises on an unstable surface would be effective in the rehabilitation of non-specific chronic low back pain (NSCLBP). The present study assessed trunk muscle activities during bridge exercise on the floor and two kinds of unstable surfaces, i.e., a balance ball and the BOSU, for individuals with and without NSCLBP. This study enrolled 17 and 18 young participants with and without NSCLBP, respectively. In the balance ball condition, both groups showed a significant increase in erector spinae activity compared to the floor condition, and the increase in activity was significantly greater in the NSCLBP group than in the control group (p = 0.038). On the other hand, neither group showed significant changes in trunk muscle activities in the BOSU condition compared to those in the floor condition. The control group showed a significant increase in internal oblique/transversus abdominis activity under the balance ball condition (p = 0.020), whereas there were no significant changes in these muscle activities between the balance ball and floor conditions in the NSCLBP group. The present study showed that participants with NSCLBP significantly increased muscle activity of the erector spinae, one of the global back muscles, on the balance ball in spite of small effects on muscle activity of the internal oblique/transversus abdominis, which is one of the local abdominal muscles. Therefore, attention should be paid to the application of bridge exercises on the balance ball for individuals with NSCLBP.

Effect of suspensory strategy on balance recovery after lateral perturbation.

Postural stability is essential for performing daily activities and preventing falls, whereby suspensory strategy with knee flexion may play a role in postural control. However, the contribution of the suspensory strategy for postural control during sudden lateral perturbation remains unclear. We aimed to determine how suspensory strategy contributed to postural adjustment during sudden perturbation in the lateral direction and what knee flexion setting maximized its effect. Eighteen healthy young adults (10 male and 8 female) participated in this study. Kinematic data during lateral perturbation at three velocities (7, 15, and 20 cm/s) were collected under three knee flexion angle conditions (0°, 15°, and 65°) using motion capture technology. Postural adjustments to the external perturbation were assessed by four parameters related to the temporal aspects of the center of mass (COM): reaction time, peak displacement/time and reversal time, and minimum value of the margin of stability (minimum-MOS). Our results showed that the COM height before the perturbation significantly lowered with increasing knee flexion angle. The COM reaction times for low and mid perturbation velocities were delayed at 65° of knee flexion compared to 0° and 15°, and the COM reversal times were significantly shorter at 65° of knee flexion than at 0° and 15° across all perturbation velocities. The minimum-MOS at the high-velocity of perturbation was significantly smaller at 65° of knee flexion than at 0° and 15°. In conclusion, the adoption of a suspensory strategy with slight knee flexion induced enhanced stability during sudden external and lateral perturbations. However, excessive knee flexion induced instability.

Hip and knee kinematics, center of pressure position, and ground reaction force are associated with Achilles tendon force during jump landing.

PURPOSE: Jump-landing exercises are often performed during the rehabilitation of Achilles tendon (AT) injuries. However, the factors that affect the AT force (ATF) during landing are unclear. This study aimed to determine the kinematics and ground reaction force (GRF) variables associated with the peak ATF during a drop vertical jump (DVJ). METHODS: The landing phase of DVJ was evaluated in 101 healthy participants (46 males, age: 21.2 ± 1.4 years old) using a three-dimensional motion analysis system with two force plates. ATF was estimated from the ankle flexion angle and moment. Univariate and multivariate regression analyses were performed with the peak ATF as the dependent variable. The vertical GRF (VGRF), center of pressure (COP), forward trunk leaning, hip/knee/ankle joint angles at peak ATF, and sex were used as independent variables. RESULTS: In the univariate regression analysis, larger VGRF (ß = 0.813), more anterior COP position (ß = 0.214), smaller knee flexion (ß = -0.251) and adduction (ß = -0.252), smaller hip flexion (ß = -0.407), smaller forward trunk lean (ß = -0.492), and male sex (ß = -0.282) were significantly associated with a larger peak ATF. Multivariate analysis revealed that larger VGRF (ß = 1.018), more anterior COP position (ß = 0.320), a larger knee (ß = 0.442), and smaller hip flexion (ß = -0.205) were associated with the larger peak ATF. CONCLUSIONS: The VGRF, COP position, and knee and hip flexion were independently associated with ATF. Modifying these factors may be useful in managing tendon loading during jump-landing exercises.

Validity of AI-Based Gait Analysis for Simultaneous Measurement of Bilateral Lower Limb Kinematics Using a Single Video Camera.

Accuracy validation of gait analysis using pose estimation with artificial intelligence (AI) remains inadequate, particularly in objective assessments of absolute error and similarity of waveform patterns. This study aimed to clarify objective measures for absolute error and waveform pattern similarity in gait analysis using pose estimation AI (OpenPose). Additionally, we investigated the feasibility of simultaneous measuring both lower limbs using a single camera from one side. We compared motion analysis data from pose estimation AI using video footage that was synchronized with a three-dimensional motion analysis device. The comparisons involved mean absolute error (MAE) and the coefficient of multiple correlation (CMC) to compare the waveform pattern similarity. The MAE ranged from 2.3 to 3.1° on the camera side and from 3.1 to 4.1° on the opposite side, with slightly higher accuracy on the camera side. Moreover, the CMC ranged from 0.936 to 0.994 on the camera side and from 0.890 to 0.988 on the opposite side, indicating a "very good to excellent" waveform similarity. Gait analysis using a single camera revealed that the precision on both sides was sufficiently robust for clinical evaluation, while measurement accuracy was slightly superior on the camera side.

Change in sensory integration and regularity of postural sway with the suspensory strategy during static standing balance.

Background and aim: The suspensory strategy, a method for controlling postural balance in the vertical direction of the center of mass (COM), is considered by the elderly as a means of balance control. The vertical COM control might alter the sensory integration and regularity of postural sway, which in turn impacts balance. However, to date, this was not confirmed. Thus, this study aimed at investigating the influence of the suspensory strategy achieved through knee flexion on the static standing balance. Methods: Nineteen participants were monitored at knee flexion angles of 0°, 15°, and 65°. Time-frequency analysis and sample entropy were employed to analyze the COM data. Time-frequency analysis was utilized to assess the energy content across various frequency bands and corresponding percentage of energy within each frequency band. The outcomes of time-frequency are hypothesized to reflect the balance-related sensory input and sensory weights. Sample entropy was applied to evaluate the regularity of the COM displacement patterns. Results: Knee flexion led to a decreased COM height. The highest energy content was observed at 65° knee flexion, in contrast with the lowest energy observed at 0° in both the anterior-posterior (AP) and medial-lateral (ML) directions. Additionally, the ultra-low-frequency band was more pronounced at 65° than that at 0° or 15° in the ML direction. Furthermore, the COM amplitudes were notably higher at 65° than those at 0° and 15° in the AP and ML directions, respectively. The sample entropy values were lower at 65° and 15° than those at 0° in the ML direction, with the lowest value observed at 65° in the vertical direction. Conclusion: The suspensory strategy could enhance the sensory input and cause sensory reweighting, culminating in a more regular balance control. Such suspensory strategy-induced postural control modifications may potentially provide balance benefits for people with declining balance-related sensory, central processing, and musculoskeletal system functions.

Association of Psychological Readiness to Return to Sports With Subjective Level of Return at 12 Months After ACL Reconstruction.

Background: Return-to-sports (RTS) rates after anterior cruciate ligament (ACL) reconstruction (ACLR) differ according to the level at which patients return. It is unclear whether the level of RTS is affected by psychological readiness to return. Purpose: To examine the association between psychological readiness to RTS and subjective RTS level 12 months after ACLR. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 47 patients who underwent unilateral primary ACLR surgery were enrolled. Assessments at 6 and 12 months postoperatively consisted of knee strength testing (isokinetic quadriceps and hamstring strength), the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC-SKF), and the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale to measure psychological readiness to RTS. Patients were assigned to 1 of 3 subgroups based on their subjective assessment of RTS level at 12 months postoperatively: RTS at or above preinjury level (RTS≥Pre; n = 19), RTS below preinjury level (RTS

Factors associated with persistent pain in college athletes with a history of lateral ankle sprain.

OBJECTIVES: To determine the factors associated with and prevalence of persistent pain in college athletes with chronic ankle instability (CAI) and with previous lateral ankle sprain (LAS) without CAI. DESIGN: Cross-Sectional Study. SETTING: Online survey at one university. PARTICIPANTS: Of the 385 respondents surveyed online, 140 were identified as having experienced at least one LAS (CAI group: 69, coper group: 24, LAS group not classified as either: 47). MAIN OUTCOME MEASURES: Factors associated with the presence of pain during activities of daily living (ADL) and sports were identified using multivariate logistic regression analyses. Independent variables were demographics, injury characteristics, the Identification of Functional Ankle Instability (IdFAI) score, the Foot and Ankle Ability Measure Sports (FAAM-Sports) and ADL subscales, and the Tampa Scale for Kinesiophobia-11 score. RESULTS: The prevalence of pain during ADL and sports in the three groups was 16.7%-42.0% and 33.3%-56.5%, respectively. FAAM-Sports and IdFAI score were significantly associated with pain during ADL and sports in the CAI group (odd ratio: 0.923 and 1.145), respectively. No significant pain-related factors were found in the coper and LAS groups. CONCLUSIONS: Lower self-reported function and greater perceived ankle instability may be important factors in pain management in athletes with CAI.

Potential factors for and the prognostic impact of ascites after allogeneic hematopoietic stem cell transplantation.

Ascites is sometimes detected after allogeneic hematopoietic stem cell transplantation (allo-HSCT); however, since limited information is currently available, its clinical meaning remains unclear. Therefore, we herein examined potential factors for and the impact of ascites on the prognosis of patients after allo-HSCT at our institutes. Fifty-eight patients developed ascites within 90 days of allo-HSCT (small in 34 (16%), moderate-large in 24 (11%)). A multivariate analysis identified veno-occlusive disease/sinusoidal obstruction syndrome (p = 0.01) and myeloablative conditioning (p = 0.01) as significant potential factors for the development of small ascites. Thrombotic microangiopathy (TMA) (p < 0.01) was a significant potential factor for moderate-large ascites. The incidence of both small and moderate-large ascites correlated with lower overall survival (p = 0.03 for small ascites and p < 0.01 for moderate-large ascites) and higher non-relapse mortality rates (p = 0.03 for small ascites and p < 0.01 for moderate-large ascites). Lower OS and higher NRM rates correlated with the incidence of both small and moderate-large ascites. Further investigation is warranted to establish whether the clinical sign of ascites improves the diagnostic quality of TMA in a large-scale study.

Cetuximab Plus Concurrent Radiotherapy in Patients With Nasopharyngeal Carcinoma.

BACKGROUND/AIM: Several reports have evaluated the efficacy and safety of concurrent radiotherapy with cetuximab (BRT) in patients with nasopharyngeal carcinoma (NPC). Combination therapy with cetuximab can be a treatment option for NPC. Although clinical data regarding the efficacy and safety of BRT without induction chemotherapy (ICT) or adjuvant chemotherapy is essential for the development of new therapeutic strategies, such data are rarely reported. PATIENTS AND METHODS: We retrospectively investigated a series of patients with NPC treated in our institution to evaluate the efficacy and safety of BRT. Eleven patients with newly diagnosed NPC were identified from an inpatient database from July 2015 to April 2018. Seven patients who received BRT were reviewed. RESULTS: All patients completed BRT without cessation of treatment. Six (85.7%) patients achieved a complete response and one (14.3%) achieved stable disease. The response rate was 85.7%. All patients with ≤T3 disease achieved a complete response. Both patients with T3 disease developed local recurrence, and one of the four patients with T1-2 disease developed distant metastases. The 1- and 3-year overall survival rates were 85.7% and 47.6%, respectively. The most common adverse events (AEs) were pharyngeal mucositis (100%), radiation dermatitis (100%), anorexia (28.6%), weight loss (28.6%), acneiform rash (28.6%), and dry mouth (28.6%). Grade 3 AEs were pharyngeal mucositis (42.9%), radiation dermatitis (28.6%), and anorexia (14.3%). No grade 4/5 AEs were observed. CONCLUSION: BRT for NPC was tolerable, but our findings suggest that BRT without induction chemotherapy or adjuvant chemotherapy is insufficient at least for ≥T3 disease.

WPOI-4/5 Correlates With Lymph Node Recurrence and Poor Prognosis in Early-stage Tongue Squamous Cell Carcinoma.

BACKGROUND/AIM: Neck management in patients with early-stage tongue cancer remains controversial. The worst pattern of invasion (WPOI) of the primary tumor has been associated with the incidence of regional metastasis. We investigated the prognostic role of WPOI, especially in relation to regional lymph node recurrence and disease-specific survival (DSS). PATIENTS AND METHODS: We retrospectively reviewed medical records and evaluated tumor specimens of 38 patients with early-stage tongue cancer who underwent primary tumor resection without elective neck dissection. RESULTS: Regional lymph node recurrence rates were significantly higher in patients with WPOI-4/5 compared with WPOI-1 to -3. The 5-year DSS rates were significantly higher for WPOI-1 to -3 than for WPOI-4/5. Notably, patients with WPOI-1 to -3 achieved a 100% 5-year DSS rate with salvage neck dissection and postoperative treatment, even those with cervical lymph node recurrence, whereas patients with WPOI-4/5 had a poorer prognosis. CONCLUSION: Patients with WPOI-1 to -3 tumors can be followed up without neck dissection until regional lymph node recurrence is detected, with a good course after salvage treatment. In contrast, patients with WPOI-4/5 tumors who are followed up until the appearance of regional lymph node recurrence have a poor prognosis, even with adequate treatment for recurrent disease.

Interlimb Asymmetry in Knee Extension Moment During Double-Leg Squatting Is Associated With Persistent Quadriceps Weakness After ACL Reconstruction.

Background: Although double-leg squatting is less dynamic and places less demand on the quadriceps compared with landing tasks, the relationship between double-leg squatting biomechanics and persistent quadriceps weakness after anterior cruciate ligament reconstruction (ACLR) is unknown. Purpose: To clarify the relationships between asymmetries in quadriceps strength and lower limb biomechanics during double-leg squatting >1 year after ACLR. Study Design: Controlled laboratory study. Methods: A total of 26 participants (5.5 ± 3.8 years after ACLR) were enrolled. The limb symmetry index (LSI) of isokinetic quadriceps strength was used to divide participants into the high-quadriceps (HQ) group (LSI ≥90%; n = 18) and the low-quadriceps (LQ) group (LSI <90%; n = 8). The knee, hip, and ankle extension moment (relative to body weight and support moment [sum of knee, hip, and ankle moments]) and vertical ground-reaction force during double-leg squatting were analyzed using 3-dimensional motion analysis. The association of quadriceps strength and biomechanical variables was tested using 2-way analysis of variance and univariate regression analysis. Results: A significant group-by-limb interaction was found for the peak knee extension moment and the ratios of knee and hip extension moment to support moment (P < .001, P = .015 and P < .001, respectively). The LQ group showed a significantly smaller peak knee extension moment and knee to support moment ratio but a larger hip to support moment ratio in the involved limb than in the uninvolved limb (95% CIs: knee extension moment, -0.273 to -0.088 N·m/kg; knee to support moment ratio, -10.7% to -2.2%; hip to support moment ratio, 3.2% to 8.5%). No interlimb difference was found for the HQ group. The LSI of quadriceps strength was significantly associated with the LSI of peak knee extension moment (R2 = 0.183), knee to support moment ratio (R2 = 0.256), and hip to support moment ratio (R2 = 0.233). The mean maximum isokinetic quadriceps strength and peak knee extension moment during squatting on the involved limb of the LQ group were 2.40 ± 0.39 and 0.90 ± 0.16 N·m/kg, respectively. Conclusion: Asymmetrical biomechanics during double-leg squatting was associated with persistent quadriceps weakness after ACLR. The LQ group had reduced knee extensor moment on the involved side during squatting despite loading at approximately half the maximum strength. Clinical Relevance: Quadriceps strengthening exercises, together with interventions to improve neuromuscular control, may reduce asymmetrical biomechanics during double-leg squatting.

Trunk Muscle Activities during Ergometer Rowing in Rowers with and without Low Back Pain.

This study aimed to determine the differences in trunk muscle activity during rowing at maximal effort between rowers with and without low back pain (LBP). Ten rowers with LBP and 12 rowers without LBP were enrolled in this study. All rowers performed a 500-m trial using a rowing ergometer at maximal effort. The amplitudes of the activities of the thoracic erector spinae (TES), lumbar erector spinae (LES), latissimus dorsi (LD), rectus abdominis (RA), and external oblique (EO) muscles were analyzed using a wireless surface electromyography (EMG) system. EMG data at each stroke were converted into 10-time series data by recording averages at every 10% in the 100% stroke cycle and normalized by maximum voluntary isometric contraction in each muscle. Two-way repeated measures analysis of variance was performed. Significant interactions were found in the activities of the TES and LES (P < 0.001 and P = 0.047, respectively). In the post hoc test, the TES activity in the LBP group was significantly higher than that in the control group at the 10% to 20% and 20% to 30% stroke cycles (P = 0.013 and P = 0.007, respectively). The LES activity in the LBP group was significantly higher than that in the control group at the 0% to 10% stroke cycle (P < 0.001). There was a main group effect on the LD activity, with significantly higher activity in the LBP group than in the control group (P = 0.023). There were no significant interactions or main effects in the EO and RA activities between the groups. The present study showed that rowers with LBP compared with those without LBP exhibited significantly higher TES, LES, and LD muscle activities. This indicates that rowers with LBP exhibit excessive back muscle activity during rowing under maximal effort.

Repetitive pitching decreases the elbow valgus stability provided by the flexor-pronator mass: the effects of repetitive pitching on elbow valgus stability.

BACKGROUND: Baseball pitching induces a large elbow valgus load, stressing the ulnar collateral ligament (UCL). Flexor-pronator mass (FPM) contraction contributes to valgus stability; however, repetitive baseball pitching may weaken the FPM contractile function. The present study investigated the effects of repetitive baseball pitching on the medial valgus stability measured using ultrasonography. We hypothesized that repetitive pitching would decrease elbow valgus stability. METHODS: This was a controlled laboratory study. Fifteen young male baseball players at the collegiate level (age: 23.0 ± 1.4 years) were enrolled. The medial elbow joint space was measured using ultrasonography (B-mode, 12-MHz linear array transducer) in the following three conditions: at rest (unloaded), under 3 kg valgus load (loaded), and under valgus load with maximal grip contraction to activate FPM (loaded-contracted). All measurements were performed before and after the pitching tasks, which comprised five sets of 20 pitches. Two-way repeated-measures analysis of variance was applied to determine changes in the medial elbow joint space. The post hoc test with Bonferroni adjustment was applied to assess the changes within the time and condition. RESULTS: The medial elbow joint space was significantly greater under the loaded than the unloaded and loaded-contracted conditions both before and after pitching (P < .001). In the loaded-contracted condition, the medial elbow joint space significantly increased after repetitive baseball pitching (P < .001). CONCLUSIONS: The results of the present study indicated that repetitive baseball pitching reduced the elbow valgus stability. This reduction could be attributed to the decreased FPM contractile function. Insufficient contraction may increase the tensile load on the UCL with pitching. FPM contraction plays a role in narrowing the medial elbow joint space; however, repetitive baseball pitching reduced the elbow valgus stability. It has been suggested that sufficient rest and recovery of the FPM function are required to reduce the UCL injury risk.