Sitting Sideways Causes Different Femoral-Tibial Rotations in Each Knee.

Purpose According to a previous study, asymmetrical kneeling, such as sitting sideways, does not exhibit asymmetrical movements. Rotational analyses of each femur and tibia help explain why rotational knee kinematics while sitting sideways do not exhibit asymmetrical movement. We aimed to assess the rotation of the femur and tibia in normal knees while sitting sideways. Methods Each volunteer sat sideways under fluoroscopy. Two-dimensional and three-dimensional registration techniques were used. After evaluating the femoral rotation angle relative to the tibia at each flexion angle, the femoral and tibial sole rotation angles at each flexion angle were compared between the ipsilateral and contralateral knees. Results While sitting sideways, both knees showed femoral external rotation relative to the tibia with flexion. In the ipsilateral knees, the femurs exhibited an external rotation of 26.3 ± 8.0°, from 110° to 150° of flexion. Conversely, the tibia exhibited an external rotation of 12.2 ± 7.8°, from 110° to 150° of flexion. From 110° to 150° of flexion, femoral external rotation was significantly larger than tibial external rotation. In the contralateral knees, the femurs exhibited an internal rotation of 23.8 ± 6.3°, from 110° to 150° of flexion (110°, p < 0.001; 120°, p < 0.001; 130°, p < 0.001; 140°, p < 0.001; and 150°, p < 0.001). Contrastingly, the tibia exhibited an internal rotation of 30.4 ± 8.8°, from 110° to 150° of flexion, which was significantly larger than femoral internal rotation (110°, p = 0.002; 120°, p < 0.001; 130°, p < 0.001; 140°, p < 0.001; and 150°, p < 0.001). Conclusions Although bilateral knees exhibited femoral external rotation relative to the tibia while sitting sideways, the ipsilateral and contralateral knees showed femoral and tibial sole rotations in opposite directions. In particular, the contralateral knees might show a strained movement because both femurs and tibias exhibited internal rotation with flexion. Patients who have undergone guided-motion total knee arthroplasty (TKA) or medial-pivot TKAs might be advised to avoid sitting sideways.

Real time artificial intelligence assisted carotid artery stenting: a preliminary experience.

BACKGROUND: Neurointerventionalists must pay close attention to multiple devices on multiple screens simultaneously, which can lead to oversights and complications. Artificial intelligence (AI) has potential application in recognizing and monitoring these devices on fluoroscopic imaging. METHODS: We report out preliminary experience with a real time AI assistance software, Neuro-Vascular Assist (iMed technologies, Tokyo, Japan), in six patients who underwent carotid artery stenting. This software provides real time assistance during endovascular procedures by tracking wires, guiding catheters, and embolic protection devices. The software provides notification when devices move out of a predefined region of interest or off the screen during the procedure. Efficacy, safety, and accuracy of the software were evaluated. RESULTS: The software functioned well without problems and was easily used. Mean number of notifications per procedure was 21.0. The mean numbers of true positives, false positives, and false negatives per procedure were 17.2, 3.8, and 1.2, respectively. Precision and recall were 82% and 94%, respectively. Among the 103 true positive notifications, 24 caused the operator to adjust the inappropriate position of the device (23%), which is approximately four times per procedure. False notifications occurred because of false positive device detection. No adverse events related to the software occurred. No periprocedural complications occurred. CONCLUSIONS: Neuro-Vascular Assist, a real time AI assistance software, worked appropriately and may be beneficial in carotid artery stenting procedures. Future large scale studies are warranted to confirm.

Effect of single-radius design on in vivo kinematics during stair activities after total knee arthroplasty.

BACKGROUND: The single-radius design is one of the major total knee arthroplasty (TKA) designs and widely used all over the world. The objective of this study was to compare in vivo kinematics between the anteroposterior (AP) single-radius design with mediolateral (ML) single-radius (Non Restricted Geometry; NRG) and ML dual-radius (Triathlon) during stair activities. METHODS: A total of 21 knees in 18 patients (NRG group: 10 knees in 7 patients, Triathlon group: 11 knees in 11 patients) with a clinically successful posterior stabilized TKA were examined. Under fluoroscopic surveillance, each patient performed stair ascending and descending motions. In vivo kinematics were analyzed using 2D/3D registration technique. The knee flexion angle, rotation angle, varus-valgus angle, AP translation of the femorotibial contact point for both the medial and lateral sides of the knee, and post-cam engagement were evaluated. RESULTS: There were no significant differences between the two groups in rotation angle and AP translation at each flexion angle. Examining the varus-valgus angle, the NRG group showed varus position at an early flexion angle during both stair activities.Post-cam engagement was observed in both groups during both stair activities. The mean flexion angle of engagement in the NRG group, the post of which was located anterior to the Triathlon, was larger than that in the Triathlon group during both stair activities. CONCLUSION: Despite the same AP single-radius TKA, ML single-radius might affect varus motion at an early flexion angle.

In Vivo Kinematics and Cruciate Ligament Tension Are Not Restored to Normal After Bicruciate-Preserving Arthroplasty.

BACKGROUND: Whether cruciate ligament forces in cruciate-preserving designs, such as unicompartmental knee arthroplasty (UKA) or bi-cruciate-retaining total knee arthroplasty (BCR-TKA), differ from those in normal knees remains unknown. The purpose of this study was to compare the in vivo kinematics and cruciate ligament force in knees before and after UKA or BCR-TKA to those in normal knees during high-flexion activity. METHODS: Overall, twenty normal knees, 17 knees with medial UKA, and 15 knees with BCR-TKA were fluoroscopically examined while performing a squatting activity. A 2-dimensional or 3-dimensional registration technique was employed to measure tibio-femoral kinematics. Ligament strains and tensions in the anteromedial bundle of the anterior cruciate ligament and posterolateral bundle of the anterior cruciate ligament and the anterolateral bundle of the posterior cruciate ligament (aPCL) and posteromedial bundle of the posterior cruciate ligament (pPCL) during knee flexion were analyzed. RESULTS: Tension in both bundles of the anterior cruciate ligament decreased with flexion. At 60° of flexion, anteromedial bundle of the anterior cruciate ligament tension in postoperative UKA knees was greater than that in normal knees. At 30° of flexion, posterolateral bundle of the anterior cruciate ligament tension in postoperative UKA knees was greater than that in normal knees. On the other hand, aPCL and pPCL tensions increased with flexion. From 40 to 110° of flexion, the postoperative aPCL tension in UKA knees was greater than that in normal knees. At 110° of flexion, the preoperative pPCL tension in UKA knees was greater than that in normal knees. In addition, the postoperative pPCL tension in UKA knees was larger than that in normal knees beyond 20° of flexion. Furthermore, the pPCL tension of postoperative BCR-TKA knees was larger than that in normal knees from 20 to 50° and beyond 90° of flexion. CONCLUSIONS: The cruciate ligament tensions, especially posterior cruciate ligament tension in knees after UKA, were greater than those in the normal knees. Surgeons performing bi-cruciat-preserving knee arthroplasties should therefore balance cruciate ligament tension more carefully in flexion and extension.

The impact of malnutrition on the effectiveness of intradialytic exercise in hemodialysis patients: amulticenter cohort study.

PURPOSE: Low physical function can be effectively improved via intradialytic exercise. However, the association between the effects of intradialytic exercise on physical function and malnutrition severity has not been studied extensively. This study aimed to investigate the impact of nutritional status severity on physical function in patients undergoing hemodialysis with low physical function to whom intradialytic exercise was prescribed. METHODS: The participants were patients with decreased mobility [walking speed < 1.0 m/s and/or Short Physical Performance Battery (SPPB) < 12] who had been undergoing hemodialysis thrice a week for 6 months and performing intradialytic exercise program. Patients were divided into groups based on the Geriatric Nutritional Risk Index (GNRI) [Non-malnutrition group (GNRI > 98), Gentle/slim malnutrition group (GNRI ≤ 98, GNRI ≥ 92), Mild malnutrition group (GNRI < 92, GNRI ≥ 82), Severe malnutrition group (GNRI < 82)]. The primary outcomes were Grip strength, isometric knee extension strength (IKES), SPPB, and 10-m walking speed measured at baseline and at 6 months. Statistical analyses were performed using a linear mixed-effects model with the intention-to-treat analysis, including within-group analysis and between-group comparison. RESULTS: A total of 805 participants were included in the study. Within-group comparisons showed significantly improved IKES, 10-m walking speed, and SPPB improved, except in the Severe malnutrition group. Grip strength significantly improved in the Gentle/slim and mild malnutrition groups. Between-group comparison with controls showed that the improvement in Grip strength was significantly bigger in the Gentle/slim malnutrition group [0.98 (0.15 to 1.82) kg] than in the non-malnutrition group. However, IKES in the Severe malnutrition group [- 5.14 (- 9.18 to - 1.10) %] less significantly improve than that in the non-malnutrition group. No significant differences were found in the other indices. CONCLUSION: In patients with severe malnutrition, the changes in IKES scores resulting from Intradialytic exercise were significantly smaller than those observed in non-malnourished patients. Therefore, it is necessary to initiate suitable nutritional and exercise therapy based on the severity of malnutrition.

Factors Associated With a Lateral Ankle Sprain in Young Female Soccer Players: A Prospective Cohort Study.

Background: Previous studies have attempted to determine if certain risk factors can predict the occurrence of a lateral ankle sprain (LAS) in female soccer players. Unfortunately, there is limited evidence with regard to risk factors associated with an LAS in female soccer players. Purpose: To identify intrinsic risk factors for an LAS among young female soccer players. Study Design: Cohort study; Level of evidence, 2. Methods: Participants were 161 young female soccer players in Japan who were evaluated for LAS risk factors during a preseason medical assessment. The assessment included anthropometric, joint laxity, joint range of motion, muscle flexibility, muscle strength, and balance measurements. Each athlete's history of LASs was also collected. The participants were monitored during a single-yearseason for LASs, as diagnosed by physicians. Results: There were 26 instances of an LAS in 25 players (15.5%) during the season. Injured players were significantly more likely to have sustained a previous ankle sprain (P = .045) and demonstrated significantly worse balance than their peers without an LAS during the double- and single-leg balance tests (P = .008 for both). Athletes with lower hamstring-to-quadriceps muscle strength ratios were also significantly more likely to sustain an LAS (P = .02). Conclusion: Poor balance, a low hamstring-to-quadriceps ratio, and a history of ankle sprains were associated with an increased risk of LASs in young female soccer players in the current study. These findings may be useful for developing a program to prevent LASs in this population.

In vivo three-dimensional kinematic comparison of normal knees between flexion and extension activities.

Background/Objective: Normal knee kinematics during flexion and extension activities over the whole range of motion remains unknown. This study aimed to clarify in vivo kinematics during knee flexion and extension activities of normal knees by comparing continuous flexion and extension activities up to a high flexion angle. Methods: Twenty knees of 10 Japanese volunteers were enrolled in this study. Each volunteer performed a continuous squatting motion under fluoroscopy, and a two- or three-dimensional registration technique was used. Rotation and anteroposterior translation of the medial and lateral sides of the femur relative to the tibia at each flexion angle were evaluated. Results: Femoral external rotation was significantly smaller from 10° to 40° flexion during extension activities than during flexion activities. However, the femoral external rotation was larger from 120° to 130° flexion during extension activities than during flexion activities. From 10° to 60° of flexion, the medial side was significantly more posteriorly located during extension activities than during flexion activities. Furthermore, the lateral side was significantly more posteriorly located at 130° of flexion during extension activities than during flexion activities. Conclusion: In vivo kinematics of normal knees during extension activities differ from those during flexion activities in early and high flexion.

Factors associated with improved health-related quality of life due to improvements in physical function and dialysis-related symptoms following intradialytic exercise in outpatients undergoing haemodialysis.

PURPOSE: Exercise therapy is a crucial intervention for improving health-related quality of life (HRQOL) in patients undergoing haemodialysis. However, factors that improve HRQOL by improving physical function and dialysis-related symptoms remain unknown. This study aimed to examine the physical function parameters and dialysis-related symptoms that improve HRQOL following intradialytic exercise. METHODS: This multicentre cohort study included 596 patients who participated in an intradialytic exercise program three times per week for a period of 6 months, which comprised of stretching and resistance training. EuroQol 5 dimensions 5-level (EQ5D-5L), grip strength, isometric knee extension strength, 10-m walking speed, Short Physical Performance Battery (SPPB), and improvement in dialysis-related symptoms were measured at the baseline and post-intervention. A linear mixed model was used to analyse the effects of improved physical function and dialysis-related symptoms on improvements in EQ5D-5L. RESULTS: As a physical function index affecting ΔEQ5D-5L, only SPPB showed a significant increase in ΔEQ5D-5L compared with the non-improved group [difference in ΔEQ5D-5L, 0.05 (0.004 to 0.092) point; p < 0.05]). In addition, dialysis-related symptoms with Improved physical conditions [difference in ΔEQ5D-5L, 0.07 (0.02 to 0.13) point] and an Extended walking distance [difference in ΔEQ5D-5L was 0.07 (0.01 to 0.12) point] significantly influenced ΔEQ5D-5L (p < 0.05, both). CONCLUSIONS: The improvements observed in the SPPB scores and self-percieved physical fitness and ambulation range, attributable to intradialytic exercise, may potentially improve HRQOL.

In Vivo Kinematic Analysis of Mobile-Bearing Unicompartmental Knee Arthroplasty during High Flexion Activities.

Mobile-bearing (MB) unicompartmental knee arthroplasty (UKA) has high conformity between the femoral articular surface and the meniscal bearing; therefore, the surface and subsurface contact stress is reduced. Additionally, the survival rate is high. However, the in vivo kinematics of MB UKA knees during high-flexion activities of daily living remain unknown. The aim of this study was to investigate in vivo the three-dimensional kinematics of MB UKA knees during high-flexion activities of daily living. A total of 17 knees of 17 patients who could achieve kneeling after MB UKA were examined. Under fluoroscopy, each patient performed squatting and kneeling motions. To estimate the spatial position and orientation of the knee, a two-dimensional/three-dimensional registration technique was used. We evaluated the femoral rotation and varus-valgus angle relative to the tibia and the anteroposterior translation of the medial sulcus (medial side) and lateral epicondyle (lateral side) of the femur on the plane perpendicular to the tibial mechanical axis in each flexion angle. From 130° to 140° of flexion, the femoral external rotation during squatting was significantly smaller than that during kneeling. Additionally, the medial side of the femur during squatting was significantly more posteriorly located compared with that during kneeling. There was no significant difference between squatting and kneeling in terms of the lateral side of the femur and the varus-valgus position in each flexion angle. At high flexion angle, the kinematics of MB UKA knees may differ depending on the performance.

Lower hamstring to quadriceps muscle strength ratio and lower body weight as factors associated with noncontact anterior cruciate ligament injury in male American football players: A prospective cohort study.

Background: Previous studies have aimed to determine the use of certain risk factors in predicting the occurrence of noncontact anterior cruciate ligament (ACL) injuries. Unfortunately, evidence regarding noncontact ACL injuries in male American football players is limited. This prospective cohort study aimed to identify intrinsic risk factors for noncontact ACL injury among male American football players. Methods: This study evaluated 152 male American football players in Japan for potential noncontact ACL injury risk factors during a preseason medical assessment, including anthropometric, joint laxity, and flexibility, muscle flexibility, muscle strength, and balance measurements. A total of 25 variables were examined. Participants were monitored during each season for noncontact ACL injury, as diagnosed by physicians. Results: Noncontact ACL injuries occurred in 11 knees of 11 players (prevalence; 7.1 %). Injured players were significantly more likely to have lightweight (P = 0.049). No statistically significant between-group differences were found for any other variables. Participants with a lower hamstring to quadriceps (H/Q) ratio (P = 0.04) were more likely to sustain noncontact ACL injuries. Conclusion: Lower H/Q ratio and lower body weight were significantly associated with new-onset noncontact ACL injury in male American football players. These findings will help develop strategies to prevent noncontact ACL injuries in male American football players.

Age-associated effects of intradialytic exercise on physical function and nutritional status in patients receiving ambulatory hemodialysis: A multicenter cohort study.

INTRODUCTION: Intradialytic exercise is essential for improving physical function for older patients. This study aimed to examine the relationship between the effects of exercise therapy and aging. METHODS: This multicenter cohort study included 1176 patients aged 40-89 years, who participated in an intradialytic exercise program, comprising stretching and resistance training, three times per week for 12 months. Isometric knee extension strength (IKES), 10-m walking speed, Short Physical Performance Battery (SPPB), and Geriatric Nutritional Risk Index (GNRI) were measured at baseline and after 12 months. The patients were divided according to age as follows: 40-59, 60-69, 70-79, and 80-89 years. A linear mixed-effects model examined the improvement within-group and between-control differences, as the 40-59 age group was the control group. FINDINGS: The 40-59, 60-69, 70-79, and 80-89 age groups comprised 180, 317, 466, and 213 participants, respectively. Within-group differences, all the age groups significantly improved IKES and SPPB. The 10-m walking speed [0.02 (0.02) m/s] and GNRI [0.38 (0.33)] did not improved only in the 80-89 age group despite other age groups significantly improved. Between-control differences, IKES of the 70-79 age group [-0.24 (-0.42 to -0.06) %] was significantly lower improvement than control. GNRI of all the older groups were significantly smaller improvement than control (p < 0.05). DISCUSSION: The older group demonstrated difficulty in improving walking ability and nutritional status compared with the younger groups. Clinicians need to consider the difference in effectiveness due to age and prescribe intradialytic exercises accordingly.

Short-term clinical results of bicruciate-retaining total knee arthroplasty using personalized alignment.

BACKGROUND: Bicruciate-retaining (BCR) prosthesis has been introduced to recreate normal knee movement by preserving both the anterior and posterior cruciate ligaments. However, the use of BCR total knee arthroplasty (TKA) is still debatable because of several disappointing reports. We have been performing BCR TKAs with personalized alignment (PA). This study aimed to reveal the limb alignment and soft tissue balance of FA-BCR TKAs and compare the clinical outcomes of FA-BCR TKAs with those of unicompartmental knee arthroplasty (UKA). METHODS: Fifty BCR TKAs and 58 UKAs were included in this study. The joint component gaps of BCR TKA were evaluated intraoperatively and the postoperative hip-knee-ankle (HKA) angle, medial proximal tibial angle (MPTA), and lateral distal femoral angle (LDFA) were measured using full-length standing radiography. The short-term clinical outcomes of BCR TKAs were compared with those of UKA using the scoring system of 2011 Knee Society Scoring (KSS) and the knee injury and osteoarthritis outcome score (KOOS) at an average of 2 years postoperatively (1-4yeras). RESULTS: The coronal alignment values of PA-BCR TKA were as follows: HKA angle, 177.9° ± 2.3°; MPTA, 85.4° ± 1.9°; and LDFA, 87.5° ± 1.9°. The joint component gaps at flexion angles of 10°, 30°, 60°, and 90° were 11.1 ± 1.2, 10.9 ± 1.4, 10.7 ± 1.3, and 11.2 ± 1.4 mm for the medial compartment and 12.9 ± 1.5, 12.6 ± 1.8, 12.5 ± 1.8 and 12.5 ± 1.7 mm for the lateral compartment, respectively. The patient expectation score and maximum extension angle of PA-BCR TKA were significantly better than those of UKAs. CONCLUSIONS: The short-term clinical outcomes of PA-BCR TKA were comparable or a slightly superior to those of UKAs.

Postoperative quadriceps weakness and male sex are risk factors for patellofemoral articular cartilage lesions after anatomical anterior cruciate ligament reconstruction.

PURPOSE: Patellofemoral (PF) compartment cartilage lesions are a frequent problem after anterior cruciate ligament (ACL) reconstruction. This study aimed to determine the factors that influence PF cartilage lesions after anatomical ACL reconstruction. METHODS: This study enrolled a total of 114 patients who did not manifest PF compartment cartilage lesions during anatomical ACL reconstruction and underwent second-look arthroscopy 18 months postoperatively. Arthroscopy using the International Cartilage Repair Society (ICRS) classification was used to assess cartilage lesions. The correlation between surgical findings, radiographic factors, and clinical factors and change of ICRS grade was analysed. Multivariate regression analysis was conducted to reveal the independent risk factors for PF cartilage lesions among patients' demographic data and parameters that correlated with the change of ICRS grade in the correlation analyses. RESULTS: ICRS grade changes in PF cartilage were significantly correlated with age, sex, quadriceps strength at 1 year postoperatively, hamstrings strength at pre- and 1 year postoperatively, and single leg hop test at 1 year postoperatively. However, no significant correlation was found between the time between injury and surgery, posterior tibial slope angle, pre- and postoperative Tegner activity scale, graft type, initial graft tension, meniscus injury, meniscus injury treatment, pre- and postoperative range of motion, anteroposterior laxity and preoperative quadriceps strength, and the change in ICRS grade. Multivariate regression analysis revealed male (P = 0.019) and quadriceps strength weakness at 1 year postoperatively (P = 0.009) as independent risk factors for PF cartilage lesions. CONCLUSIONS: Quadriceps strength weakness 1 year after ACL reconstruction and males were correlated with a new PF cartilage lesion after anatomical ACL reconstruction, with no significant correlation between bone-patellar tendon-bone autograft, initial graft tension, or extension deficit and new PF cartilage lesion. Rehabilitation that focuses on quadriceps strength after ACL reconstruction is recommended to prevent new PF cartilage lesions. LEVEL OF EVIDENCE: Level IV.

Differences in the purpose of exercise between hemodialysis patients who continued or dropped out of exercise programs: a multicenter cohort study.

BACKGROUND: Selecting suitable exercise goals is crucial for fostering adherence to, and maintenance of, exercise therapy. We aimed to evaluate the variance in exercise objectives between individuals who continued and those who dropped out of a 6-month intradialytic exercise program by analyzing an open-ended questionnaire administered to patients undergoing hemodialysis. METHODS: The study consisted of outpatients (n = 541; mean age, 70 years) undergoing maintenance hemodialysis, who had been informed of an intradialytic exercise program and voluntarily agreed to participate. The primary outcome was the exercise purpose. The difference in exercise purpose was quantitatively analyzed between the exercise continuation and dropout groups. A co-occurrence network was created and concepts were constructed. The basic attributes were compared using chi-squared and independent t-tests. RESULTS: Over 6 months, 154 patients (28.5%) dropped out of the intradialytic exercise program. Concepts related to the goals of the program were: (1) physical function and condition, (2) addressing limitations, (3) maintaining daily life activities, and (4) physical condition recognition. Co-occurrence network analysis showed that the exercise continuation group established their objectives based on the health benefits of exercise, and proactively set goals rooted in comprehending their current issues and problems. The dropout group tended to perceive treatment passively as an extension of daily clinical practice, rather than actively formulating exercise objectives. CONCLUSION: The exercise objectives of those who continued the exercise program differed from those who dropped out. Patients in the exercise continuation group set more affirmative and specific exercise objectives, whereas those in the dropout group set more passive and abstract exercise objectives.

Comparison of finite helical axis of the knee joint before and after bi-cruciate-preserving knee arthroplasty.

BACKGROUND: Difference in the finite helical axis of the knee joints before and after anterior cruciate ligament-preserving knee arthroplasties such as unicompartmental knee arthroplasty and bi-cruciate-retaining total knee arthroplasty remains unknown. This study compared the knee finite helical axes before and after bi-cruciate-preserving knee arthroplasty. METHODS: Patients undergoing medial unicompartmental knee arthroplasty and bi-cruciate-retaining total knee arthroplasty were included. Under fluoroscopy, participants performed a deep knee bend before and after surgery. A two/three-dimensional registration technique was employed to measure tibiofemoral kinematics. Femoral finite helical axis was calculated in a flexion range of 0-120° using 30° windows (early-, mid-, late-, and deep-flexion phases). FINDINGS: In unicompartmental knee arthroplasty, the preoperative knee vertical angle was larger than the postoperative vertical angle in mid- and deep-flexion phases. The postoperative knee vertical angle was smaller in unicompartmental knee arthroplasty than in bi-cruciate-retaining total knee arthroplasty. In unicompartmental knee arthroplasty, the preoperative horizontal angle was smaller than the postoperative horizontal angle in the early-flexion phase. However, in bi-cruciate-retaining total knee arthroplasty, the preoperative horizontal angle was larger than the postoperative horizontal angle in mid- and deep-flexion phases. The horizontal angle was smaller before unicompartmental knee arthroplasty than that before bi-cruciate-retaining total knee arthroplasty in early-, mid-, and deep-flexion phases. However, the vertical angle was larger after unicompartmental knee arthroplasty than that after bi-cruciate-retaining total knee arthroplasty in the early-flexion phase. INTERPRETATION: The knee finite helical axes before and after unicompartmental knee arthroplasty differed from those before and after bi-cruciate-retaining total knee arthroplasty.

Association between depressive symptoms and heart rate variability in older patients admitted for rehabilitation: a cross-sectional study.

Heart rate variability (HRV) is associated with depressive symptoms, but this relationship in older inpatients undergoing rehabilitation remains unclear. This study investigated the relationship between HRV and depressive symptoms in older inpatients undergoing rehabilitation. Fifty patients aged ≥65 years were assessed for depressive symptoms using the Geriatric Depression Scale. HRV was assessed by frequency analysis. The relationship between depressive symptoms and HRV indices, age, sex, Short Physical Performance Battery (SPPB) score, Mini-Mental State Examination score was examined using simple linear regression. Next, the predictors from the simple linear regression analysis significant at the 0.15 level were inputted in a multiple regression model. Multiple regression analysis revealed that very low frequency HRV [ ß = -2.13, 95% confidence interval (CI) -3.15 to -1.11, P  < 0.05] and SPPB score ( ß = -0.30, 95% CI -0.52 to -0.08, P  < 0.05) were negatively associated with depressive symptoms: the lower the HRV and the more severe the mobility impairment, the higher the severity of the depressive symptoms. Very low frequency (VLF) HRV and physical performance, as measured by the SPPB score, were associated with depressive symptoms in older patients undergoing rehabilitation. VLF HRV may serve as a useful biomarker for detecting depressive symptoms in this population.

Risk factors for hamstring strain injury in male college American football players -a preliminary prospective cohort study.

BACKGROUND: Given the frequency of hamstring strain injuries (HSI) among male college American football players, several studies have attempted to determine whether certain risk factors can predict their occurrence. However, no consensus on modifiable risk factors for HSIs in male college American football players has yet been reached to prevent these injuries. This study aimed to clarify risk factors for HSI prospectively in college male American football players. METHODS: A total of 78 male college American football players, whose positions were limited to skill positions, were medically assessed for potential risk factors of HSI. The preseason medical assessment included anthropometric measurements, joint laxity and flexibility, muscle flexibility, muscle strength, and balance ability. RESULTS: HSI occurred in a total of 25 thighs from 25 players (32.1%). Injured players had significantly lower hamstring flexibility (p = 0.02) and hamstring to quadriceps strength ratio (H/Q) (p = 0.047) compared to uninjured players. Additionally, injured players had significantly lower general joint laxity scores, especially for the total (p = 0.04), hip (p = 0.007), and elbow (p = 0.04) scores, compared to uninjured players. CONCLUSIONS: Lower hamstring flexibility, lower hamstring to quadriceps strength ratio, and lower general joint laxity score were identified as risk factors for HSI in male college American football players placed in skill positions. The muscle flexibility and H/Q ratio could be useful in preventing HSI in such players.

Bicruciate-retaining total knee arthroplasty procedure reduced tensile force in the middle and posterior components of lateral collateral ligament during deep knee flexion activities with no effect on tensile force of the medial collateral ligament.

PURPOSE: To analyse the effects of bicruciate-retaining total knee arthroplasty (BCR-TKA) on the tensile force of the collateral ligaments during two deep knee flexion activities, cross-leg sitting and squatting. METHODS: Thirteen patients (15 knees) treated using bicruciate-retaining total knee arthroplasty (BCR-TKA) for knee joint osteoarthritis were analysed. Knee joint kinematics during cross-leg sitting (open-chain flexion) and squatting (closed-chain flexion) were evaluated through fluoroscopy. The tensile force was calculated in vivo based on the change in the distance between the femoral and tibial attachment areas for the anterior, middle, and posterior components of the superficial (sMCL) and deep (dMCL) medial collateral ligament and the lateral collateral ligament (LCL). Differences in the calculated tensile forces of the collateral ligaments were evaluated using repeated measures of analysis of variance, with post hoc pairwise comparison (Bonferroni test). Statistical significance was set at P ≤ 0.05. RESULTS: The correction of the coronal alignment was related to the surgical technique, not to the implant design. No significant change in the tensile force in all three components of the sMCL from pre- to post-TKA (n.s.) was observed. For dMCL, a pre- to post-TKA change in the tensile force was observed only for the anterior dMCL component (p = 0.03). No change was observed in the tensile force of the anterior LCL with increasing flexion, with no difference in pre- to post-TKA and between activities (n.s.). In contrast, tensile force in the middle LCL slightly decreased with increasing flexion during squatting, pre- and post-TKA. After surgery, lower forces were generated at 40° of flexion (p = 0.04). Tensile force in the posterior LCL was higher in extension than flexion, which remained high in the extension post-TKA. However, after surgery, lower tensile forces were generated at 10° (p = 0.04) and 40° (p = 0.04) of flexion. CONCLUSIONS: The in vivo change in tensile forces of the collateral ligaments of the knee before and after BCR-TKA can inform the development of appropriate ligament balancing strategies to facilitate recovery of deep knee flexion activities after TKA, as well as for continued improvement of BCR-TKA designs. LEVEL OF EVIDENCE: III.

Factors associated with dropout from an intradialytic exercise program among patients undergoing maintenance hemodialysis.

BACKGROUND: Continuation of an intradialytic exercise program is necessary to improve and maintain physical function in patients undergoing hemodialysis. Factors associated with dropout must be identified to ensure program continuation. This study aimed to investigate the dropout rates from an intradialytic exercise program at 6 and 12 months in patients undergoing hemodialysis and to identify dropout predictors. METHODS: This was a multicenter, retrospective observational study. Overall, 980 patients were enrolled in this study. Grip strength, 10-m walking speed, physical function, demographics and blood sampling data were measured at baseline, and dropouts were observed. Patients were classified as either continued or dropped out of the program at 6 and 12 months. The dropout rate was calculated for each time point. Multivariate logistic regression analysis was performed to identify the predictors of dropout. RESULTS: The dropout rate was 26.4% (n = 259) after 6 months, 24.1% (n = 172) between 6 and 12 months, and 44.3% (n = 424) overall at 1 year. Significant predictors of dropout after 6 months were slower 10-m walking speed, older age and high C-reactive protein level. Predictors of dropout after 12 months were slower 10-m walking speed and lower standardized dialysis volume. CONCLUSIONS: Walking capacity, age, inflammation and hemodialysis volume were determinants of dropout from the exercise program. Our findings provide new and important insights into the potential risk factors for dropout from long-term intradialytic exercise programs in patients undergoing hemodialysis.