Foot Problems and Their Associations with Toe Grip Strength and Walking Speed in Community-Dwelling Older Individuals Using Day Services: A Cross-Sectional Study.

Foot disorders in older individuals compromise balance and contribute to postural and gait instabilities, causing a decrease in the activities of daily living and quality of life. In this cross-sectional study, we analyzed the foot-related data of 160 frail older participants who attended day service centers in A prefecture in Japan to determine the prevalence of foot problems and their associations with toe grip strength and walking speed in frail older people. Multiple regression analysis was used to identify foot-related variables that correlated with toe grip strength and walking speed. The prevalence rates of skin dryness (Support level 88.2%, Care level 85.2% for men; Support level 84.9%, Care level 93% for women) and suspected and existing fungal infections in nails (Support level 94.1%, Care level 92.6% for men; Support level 98.1%, Care level 95.2% for women) were high in both sexes regardless of the level of care required. Furthermore, in both sexes, the prevalence rates of toe and arch deformities were significantly increased in the people who required care. Regression analysis revealed that some right-sided foot-related problems were significantly associated with right toe grip strength and walking speed. The decrease in toe grip strength was significantly associated with walking speed. Our study provides evidence that some specific conditions were associated with toe grip force and walking speed. This finding can contribute to future strategies to protect foot health in community-dwelling older individuals.

Preoperative Factors Affecting Patient-reported Outcome Measures for Total Knee Arthroplasty.

Objectives: The aim of this study was to investigate the preoperative factors affecting health-related quality of life (HRQOL) at 3 and 12 months after total knee arthroplasty (TKA). Methods: In total, 156 patients who underwent unilateral TKA for knee osteoarthritis were included in the study. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used as a measure of HRQOL before surgery and 3 and 12 months post-TKA. The Modified Gait Efficacy Scale (mGES) score, tibiofemoral angle, rest pain, walking pain, knee joint range of motion, knee joint extensor strength, and walking speed were recorded preoperatively. Pearson's correlation coefficient and the correlation ratio were used to calculate the correlation between KOOS and preoperative factors at 3 and 12 months post-TKA. Multiple regression analysis was performed using the stepwise method with the five postoperative KOOS subscales as dependent variables and the other preoperative factors as independent variables. Results: Preoperative mGES scores were significantly correlated with KOOS Activities of Daily Living, Sport/Rec, and QOL subscores at 3 months post-TKA and with all five KOOS subscales at 12 months post-TKA. Multiple regression analysis identified mGES as an influencing factor for all KOOS subscales except Pain at 3 months post-TKA and all KOOS subscales except Symptoms at 12 months post-TKA. Conclusions: Preoperative walking self-efficacy influenced HRQOL at 3 and 12 months post-TKA. Psychological factors such as self-efficacy should be considered when predicting postoperative outcomes.

Association between foot posture and tibiofemoral contact forces during barefoot walking in patients with knee osteoarthritis.

BACKGROUND: Accumulating evidence indicates that abnormal foot posture are risk factors for knee osteoarthritis (OA). However, the relationship between foot posture and tibiofemoral contact force (CF) during habitual weight-bearing activities remains unclear. This study aimed to determine the association between tibiofemoral CF and foot posture while walking. METHODS: In total, 18 patients with knee OA and 18 healthy individuals participated in this cross-sectional study. Foot parameters were evaluated by Foot Posture Index (FPI), Staheli Arch Index (SAI), hallux valgus angle, calcaneus inverted angle relative to the floor as a static rearfoot posture, navicular height, and toe grip strength. In addition, all participants underwent kinetic and kinematic measurements during a self-selected speed gait. The measurement device used was the three-dimensional motion analysis system with a sampling rate of 120 Hz. The musculoskeletal model, which has 92 Hill-type muscle-tendon units with 23 degrees of freedom, was used to calculate tibiofemoral CF. Partial correlations was used to investigate the association between foot parameters and total, medial, and lateral tibiofemoral CF of the first and second peaks while controlling for gait speed. RESULTS: A significant negative correlation was observed between Walking SAI and first peak medial tibiofemoral CF in control participants (r = -0.505, p = 0.039). SAI was also significantly positively correlated with first peak medial tibiofemoral CF in patients with knee OA (r = 0.482, p = 0.042). CONCLUSIONS: Our findings revealed a correlation between the medial first peak tibiofemoral CF and the SAI. This study indicates that people with knee OA and flatfoot have excessive first medial tibiofemoral CF during walking.

Effect of Tilt-in-Space and Reclining Angles of Wheelchairs on Normal Force and Shear Force in the Gluteal Region.

Healthcare workers need to educate patients regarding proper sitting positions to prevent pressure injuries in the elderly and disabled. The purpose of this study was to investigate the differences in normal and shear force in the gluteal region using the combination of tilt-in-space and reclining functions of wheelchairs. Twelve healthy subjects were recruited. Protocols for 15 wheelchair tilt-in-space and reclining angles, including three reclining angles (0°, 10°, and 20°) and five tilt-in-space (0°, 5°, 10°, 15°, and 20°), were randomly assigned. To measure the amount of normal and shear force applied to the gluteal region while sitting on a wheelchair, a force plate was placed on the seat to measure the seat reaction force. For statistical analysis, a two-factor analysis of variance, with tilt-in-space and reclining, was performed for each normal and shear force. The normal force showed a significant decrease with increased reclining angle. For the shear force combined with sagittal and lateral components, the 10° tilt-in-space showed a significant decrease compared to other conditions. The combination of 20° reclining and 10° tilt-in-space angles may decrease both normal and shear force in the gluteal region while sitting. These findings may help wheelchair-dependent individuals avoid pressure injuries.

Footsteps and walking trajectories during the Timed Up and Go test in young, older, and Parkinson's disease subjects.

BACKGROUND: Footsteps and walking trajectories during the Timed Up and Go test (TUG), and their relationships with spatiotemporal gait parameters during turning in people with Parkinson's disease (PD) and older people have not been clarified. RESEARCH QUESTION: We investigated the footsteps, walking trajectories, and spatiotemporal parameters during the TUG in PD, healthy older (HO), and healthy young (HY) subjects and the associations between the parameters of footsteps or walking trajectories and the spatiotemporal parameters during turning. METHODS: Twenty-six PD, 20 HO, and 20 HY subjects participated. They performed the TUG at self-selected speed and underwent evaluations of spatiotemporal parameters in the forward, turning, and return phases and parameters of footsteps and walking trajectories by a system using laser range sensors to measure the two-dimensional distance data of the legs. Foot placement for each foot was measured as the estimated position when the leg speed of movement reached the minimum between foot-contact and foot-off. We calculated the minimum distance from a TUG marker to footsteps and the maximum anterior distance from the start to the footsteps. Step length was calculated using a method for non-linear walking. RESULTS: The PD subjects showed significantly smaller step lengths in all phases. The minimum distance from the marker to the footsteps in PD subjects was significantly smaller than in HO subjects and was significantly positively correlated only with the turning-phase step length. The maximum anterior distance from the start to footsteps in HO subjects was significantly larger than in PD and HY subjects and was not correlated with any spatiotemporal parameters. SIGNIFICANCE: This study demonstrated that people with PD turn close to the TUG marker, and this turning strategy may be associated with the decreased step length when turning. These findings could help in providing instructions which prevent the exaggeration of step-length reduction when turning.

Physical Fitness Testing and Screening Reveal a Gateway to Identify Locomotive Disorders: Retrospective Study of a Japanese Elementary School Population.

This retrospective epidemiological study investigated the relationship between physical fitness testing and locomotive disorder screening results among elementary school children in Japan. The test and screening results of 1033 children from a single elementary school between 2016 and 2018 were examined. Multiple regression analysis was performed for each gender of children of grades third and fourth to generate receiver-operating characteristic curves. Of the 69 children with parent-identified locomotor problems, 29 (42%) had physical fitness test score of mean ± 2 SD. For the standing long jump test in fourth grade girls, the results differed significantly (P < .001; cut-off, 127 cm) for children whose parents did (n = 7) and did not (n = 84) suspect a possible locomotive disorder. Physical fitness testing in combination with school-based screening for locomotive disorders may be useful for identifying and accurately diagnosing these disorders in children.

Estimation of Vertical Ground Reaction Force Using Low-Cost Insole With Force Plate-Free Learning From Single Leg Stance and Walking.

For the evaluation of pathological gait, a machine learning-based estimation of the vertical ground reaction force (vGRF) using a low-cost insole is proposed as an alternative to costly force plates. However, learning a model for estimation still relies on the use of force plates, which is not accessible in small clinics and individuals. Therefore, this paper presents a force plate-free learning from a single leg stance (SLS) and natural walking measured only by the insoles. This method used a linear least squares regression that fits insole measurements during SLS to body weight in order to learn a model to estimate vGRF during walking. Constraints were added to the regression so that vGRF estimates during walking were of proper magnitude, and the constraint bounds were newly defined as a linear function of stance duration. Moreover, a lower bound for the estimated vGRF in mid-stance was added to the constraints to enhance estimation accuracy. The vGRF estimated by the proposed method was compared with force platforms for 4 healthy young adults and 13 elderly adults including patients with mild osteoarthritis, knee pain, and valgus hallux. Through the experiments, the proposed learning method had a normalized root mean squared error under 10% for healthy young and elderly adults with stance durations within a certain range (600-800 ms). From these results, the validity of the proposed learning method was verified for various users requiring assessment in the field of medicine and healthcare.

The muscle pre-activity timing of the hamstrings and quadriceps during 180° and 360° rotational jump landings in healthy female subjects.

BACKGROUND/OBJECTIVE: The muscle activity before the initial contact between during jump landings is referred to as the pre-activity. The muscle pre-activity that occur during jump landing are considered to be an important predictor of non-contact anterior cruciate ligament (ACL) injury risk. ACL injury prevention programs have been widely conducted; these programs are generally focused on increasing the muscle pre-activity and include rotational jump landing. The purpose of this study was to investigate the timing of the muscle pre-activity of the hamstrings and quadriceps during 180° and 360° rotational jump landing. METHODS: The participants were 10 healthy females. Electromyography was conducted on the knee joint muscles of the left leg (the non-dominant leg) during clockwise 180° and 360° rotational jump landings. RESULTS: The muscle pre-activities during 180° rotational jump landing was VM: 35.68 ±â€¯11.22 msec, RF: 38.05 ±â€¯14.77 msec, VL: 47.10 ±â€¯19.96 msec, BF: 115.63 ±â€¯30.48 msec and SM: 136.45 ±â€¯47.52 msec. And the muscle pre-activities during 360° rotational jump landing was VM: 45.25 ±â€¯17.41 msec, RF: 42.38 ±â€¯13.35 msec, VL: 48.75 ±â€¯19.20 msec, BF: 132.20 ±â€¯46.74 msec and SM: 140.70 ±â€¯40.64 msec. For both the 180° rotational jump landing and the 360° jump landing, the pre-activities of the hamstrings occurred significantly earlier than those of the quadriceps (p < 0.01). CONCLUSION: The results of the present study indicate that it may be beneficial for ACL injury prevention programs to include rotational jump landing tasks.

Reliability and responsiveness of a goniometric device for measuring the range of motion in the dart-throwing motion plane.

Background: Dart-throwing motion (DTM) is an important component of wrist function and, consequently, has the potential to become an evaluation tool in rehabilitation. However, no measurement method is currently available to reliably measure range of motion (ROM) of the wrist in the DTM plane. Objectives: To determine the reliability and responsiveness of a goniometric device to measure wrist ROM in the DTM plane. Methods: ROM of the wrist in the DTM plane was measured in 70 healthy participants. The intra-class correlation coefficient (ICC) was used to evaluate the relative reliability of measurement, and a Bland-Altman analysis conducted to establish its absolute reliability, including the 95% limits of agreement (95% LOA). The standard error of the measurement (SEM) and minimal detectable change at the 95% confidence level (MDC95) were calculated as measures of responsiveness. Results: The intra-rater ICC was 0.87, and an inter-rater ICC of 0.71. There was no evidence of a fixed or proportional bias. For intra- and inter-rater reliability, 95% LOA ranged from -13.83 to 11.12 and from -17.75 to 16.19, respectively. The SEM and MDC95 were 4.5° and 12.4°, respectively, for intra-rater reliability, and 6.0° and 16.6°, respectively, for inter-rater reliability. Conclusion: The ROM of the wrist in the DTM plane was measured with fair-to-good reliability and responsiveness and, therefore, has the potential to become an evaluation tool for rehabilitation.

Relationship Between Muscle Strength Asymmetry and Body Sway in Older Adults.

The purpose of this study was to investigate the relationship between muscle strength asymmetry and body sway while walking. We studied 63 older adult women. Strong side and weak side of knee extension strength, toe grip strength, hand grip strength, and body sway while walking were measured. The relationship between muscle strength asymmetry for each muscle and body sway while walking was evaluated using Pearson's correlation coefficient. Regarding the muscles recognized to have significant correlation with body sway, the asymmetry cutoff value causing an increased sway was calculated. Toe grip strength asymmetry was significantly correlated with body sway. Toe grip strength asymmetry causing an increased body sway had a cutoff value of 23.5%. Our findings suggest toe grip strength asymmetry may be a target for improving gait stability.

The association between toe grip strength and osteoarthritis of the knee in Japanese women: A multicenter cross-sectional study.

We evaluated the relationship between altered foot function and knee osteoarthritis through a specific comparison of toe grip strength in older women with and without knee osteoarthritis. Participants were 120 women with knee osteoarthritis (OA group) and 108 healthy community-dwelling women with no history of knee pain and lower limb surgery (control group). The following factors and outcome variables were included in our analysis: measured toe grip strength, isometric knee extension strength, the timed Up-and-Go, and the WOMAC scale. Between-group differences were compared using unpaired t-tests for descriptive characteristics and outcome measures. Pearson's correlation coefficients between toe grip strength and age, body mass index, and other outcome measures were calculated. Multiple logistic regression analysis was used to evaluate the independence of toe grip strength and knee osteoarthritis. Compared to the control group, participants in the OA group were older, heavier, and had a higher body mass index. Toe grip strength and isometric knee extension strength were lower and the timed Up-and-Go longer for the OA group than the control group. Toe grip strength was correlated with age negatively and isometric knee extension strength positively in the OA group and to age and the timed Up-and-Go negatively, and isometric knee extension strength positively in the control group. Multiple logistic regression analysis revealed that body mass index, isometric knee extensor strength, and toe grip strength were independently associated with knee osteoarthritis. Our findings indicate a probable association between altered forefoot function and the incidence or progression of knee osteoarthritis. Increasing toe grip strength might provide a practical intervention for patients with knee osteoarthritis.

Effect of floating toes on knee and trunk acceleration during walking: a preliminary study.

[Purpose] This study investigated the effect of floating toes on knee and trunk acceleration during walking in experimental setting. [Subjects and Methods] Twelve healthy volunteers walked barefoot at a preferred speed along a linear pathway under 2 conditions: normal gait (control) condition and floating toes (FT) condition. In the latter, weight bearing by the toes was avoided using kinesiology tape applied along the toe extensors. Accelerations of the knee (Kn) and lumbar spine (Lx) were assessed using triaxial accelerometers mounted on the right fibular head and the spinous process of L3. Acceleration vectors were oriented such that the anterior, right, and cranial deviations were positive along the anteroposterior, lateral, and vertical axes, respectively. The root mean squares (RMSs; anteroposterior, RMSap; lateral, RMSl; vertical, RMSv) were calculated, and the mean values of 3 trials in each condition were determined. Differences between the conditions were assessed using the Wilcoxon signed-rank test. [Results] LxRMSap and LxRMSv were larger in the FT condition than in the control condition. KnRMSv tended to be higher in the FT condition than in the control condition. [Conclusion] Floating toes increase acceleration and might create mechanical stress on the lower back and knee during walking.

Association between floating toe and toe grip strength in school age children: a cross-sectional study.

[Purpose] This study investigated the association between floating toe and toe grip strength. [Subjects and Methods] A total of 635 Japanese children aged 9-11 years participated in this study. Floating toe was evaluated using footprint images, while toe grip strength was measured using a toe grip dynamometer. All 1,270 feet were classified into a floating toe group and a normal toe group according to visual evaluation of the footprint images. Intergroup differences in toe grip strength were analyzed using the unpaired t-test and logistic regression analysis adjusted for age, gender, and Rohrer Index. [Results] There were 512 feet (40.3%) in the floating toe group. Mean toe grip strength of the feet with floating toe was significantly lower than that of normal feet (floating toe group, 12.9 ± 3.7 kg; normal toe group, 13.6 ± 4.1 kg). In addition, lower toe grip strength was associated with floating toe on logistic regression analysis after adjustment for age, gender, and Rohrer Index (odds ratio, 0.954; 95% confidence interval, 0.925-0.984). [Conclusion] This study revealed that lower toe grip strength was significantly associated with floating toe. Therefore, increasing toe grip strength may play a role in preventing floating toe in school age children.

The Relationship Between Toe Grip Strength and Dynamic Balance or Functional Mobility Among Community-Dwelling Japanese Older Adults: A Cross-Sectional Study.

Evaluating toe flexor strength may be an important method for predicting and preventing walking dysfunction and falls, particularly among older adults. In this study, toe grip strength (TGS), the functional reach (FR, a measure of dynamic balance) test, the timed up and go (TUG) test (a measure of functional ability), isometric knee extension strength (IKES), sex, age, weight, and height were analyzed among 665 healthy Japanese older adults. Statistical analyses were used to assess the relationships between TGS and FR or TUG and to investigate whether TGS was independently associated with FR or TUG. Our results indicate that, among both men and women, TGS was associated with TUG, independent of age, height, weight, and IKES, but TGS was not associated with FR. These results may facilitate the development of strategies for improving functional mobility through physical therapy.

Association of Varus Thrust With Pain and Stiffness and Activities of Daily Living in Patients With Medial Knee Osteoarthritis.

BACKGROUND: Increasing evidence highlights potential associations between varus thrust and health domains associated with knee osteoarthritis (OA). OBJECTIVE: The aim of this study was to investigate the association between varus thrust and 2 subcategories-"pain and stiffness" and "activities of daily living (ADL)"-of the Japanese Knee Osteoarthritis Measure (JKOM). DESIGN: This was a cross-sectional study. METHODS: In total, 296 outpatients with knee OA visiting orthopedic clinics were enrolled. The inclusion criteria were age ≥50 years, medial knee OA and Kellgren-Lawrence (K/L) grade ≥1 in one or both knees, and the ability to walk independently. Standard posterior-anterior knee radiographs were measured for varus alignment. Participants were video recorded while walking and were evaluated for the presence or absence of varus thrust. Pain and stiffness of the knee joint and ADL were evaluated using the JKOM. Multivariate regressions (outcomes: pain and stiffness and ADL; predictor variable: varus thrust) were performed. RESULTS: Varus thrust was present in 46 (16.2%) of 284 patients. Multivariate regression analyses demonstrated that varus thrust is independently associated with pain and stiffness, adjusted for age, sex, body mass index, K/L grade, and varus alignment (ß=.17, P=.005). However, the association between varus thrust and ADL was not significant (ß=.11, P=.058). Based on sensitivity analyses, including participants of K/L grade 1 had little influence on this analysis. LIMITATIONS: Only 16.2% of participants had a varus thrust. Moreover, a cause-effect relationship between varus thrust and pain and stiffness remains unknown due to the cross-sectional design of this study. CONCLUSIONS: Varus thrust was associated with pain and stiffness in patients with medial knee OA. However, the association between varus thrust and ADL did not reach significance.

Clinical Impact of Coexisting Patellofemoral Osteoarthritis in Japanese Patients With Medial Knee Osteoarthritis.

OBJECTIVE: To evaluate the clinical impact in knee osteoarthritis (OA) of coexisting patellofemoral (PF) joint OA (PFOA) in Japanese patients with medial tibiofemoral (TF) joint OA (TFOA). METHODS: Patients with medial knee OA (n = 143) were enrolled. The radiographic severity of the TF and PF joints, anatomic axis angle of the TF joint, patellar alignment, trochlear morphology, patellar height, and passive range of motion (ROM) of the painful knee were evaluated. Additionally, the Japanese Knee Osteoarthritis Measure (JKOM) was used to investigate the association between the presence of PFOA and clinical symptoms. RESULTS: PFOA was present in 98 of 143 patients (68.5%) with medial knee OA. Quantile regression analysis revealed that coexisting PFOA was associated with the pain-related subcategory of the JKOM. Furthermore, multiple logistic regression analysis showed that coexisting PFOA was associated with higher odds of reporting knee pain on using stairs while ascending (odds ratio [OR] 4.81 [95% confidence interval (95% CI) 1.73, 14.3]) and descending (OR 3.86 [95% CI 1.44, 10.8]). A more varus knee alignment and lower knee flexion ROM, which are features of patients with coexisting PFOA, were associated with knee pain while ascending/descending stairs. However, patellar alignment, trochlear morphology, and patellar height were not significantly associated with knee pain. CONCLUSION: PFOA coexisting with medial knee OA was associated with worse clinical symptoms, particularly while ascending/descending stairs, although patellar alignment did not contribute to reporting knee pain. Further studies that include evaluation of the PF joint are warranted to develop a basis for an optimal intervention based on compartmental involvement.

Children with flat feet have weaker toe grip strength than those having a normal arch.

[Purpose] This study investigated the relationship between toe grip strength and foot posture in children. [Subjects and Methods] A total of 619 children participated in this study. The foot posture of the participants was measured using a foot printer and toe grip strength was measured using a toe grip dynamometer. Children were classified into 3 groups; flatfoot, normal, and high arch, according to Staheli's arch index. The differences in demographic data and toe grip strength among each foot posture group were analyzed by analysis of variance. Additionally, toe grip strength differences were analyzed by analysis of covariance, adjusted to body mass index, age, and gender. [Results] The number of participants classified as flatfoot, normal, and high arch were 110 (17.8%), 468 (75.6%), and 41 (6.6%), respectively. The toe grip strength of flatfoot children was significantly lower than in normal children, as shown by both analysis of variance and analysis of covariance. [Conclusion] A significant difference was detected in toe grip strength between the low arch and normal foot groups. Therefore, it is suggested that training to increase toe grip strength during childhood may prevent the formation of flat feet or help in the development of arch.

Associations between toe grip strength and hallux valgus, toe curl ability, and foot arch height in Japanese adults aged 20 to 79 years: a cross-sectional study.

BACKGROUND: The associations between toe grip strength (TGS) and foot structure are not well known, although foot structure is inferred to affect TGS. This study investigated the associations between TGS and hallux valgus angle (HVA), toe curl ability, and foot arch height (FAH). METHODS: This study analysed 227, 20 to 79-year-old, community-dwelling participants. TGS, HVA formed by the first metatarsal bone and the proximal phalanx of the hallux, toe curl ability (percentage) calculated as (foot length-flexed foot length)/foot length, and FAH (percentage) calculated as navicular height/truncated foot length were measured. To elucidate associations between TGS and foot structure, a correlation analysis and stepwise multivariate linear regression analyses were performed, based on the participant's sex. Pearson's correlation coefficients for TGS with age, height, weight, HVA, toe curl ability, and FAH were also calculated. In the stepwise, multivariate linear regression analyses, the independent variable was TGS and the dependent variables were those that significantly correlated with TGS, as shown by the Pearson's correlation coefficients. The significance level was set at 5%. RESULTS: According to the Pearson's correlation coefficients, in men, TGS was significantly correlated with age, height, toe curl ability, and FAH. According to the stepwise multiple regression analysis, TGS correlated with age and toe curl ability (adjusted R(2)=0.22). In women, TGS was significantly correlated with age, height, and toe curl ability (adjusted R(2)=0.40). CONCLUSIONS: TGS was associated with toe curl ability in both men and women. However, TGS was not associated with HVA and FAH in men or women. The results of this study may lead to the development of effective interventions to improve TGS. However, factors other than structure of the foot require more detailed investigation to clarify the factors contributing to TGS.

Clinical Phenotype Classifications Based on Static Varus Alignment and Varus Thrust in Japanese Patients With Medial Knee Osteoarthritis.

OBJECTIVE: To investigate the association between knee pain during gait and 4 clinical phenotypes based on static varus alignment and varus thrust in patients with medial knee osteoarthritis (OA). METHODS: Patients in an orthopedic clinic (n = 266) diagnosed as having knee OA (Kellgren/Lawrence [K/L] grade ≥1) were divided into 4 phenotype groups according to the presence or absence of static varus alignment and varus thrust (dynamic varus): no varus (n = 173), dynamic varus (n = 17), static varus (n = 50), and static varus + dynamic varus (n = 26). The knee range of motion, spatiotemporal gait parameters, visual analog scale scores for knee pain, and scores on the Japanese Knee Osteoarthritis Measure were used to assess clinical outcomes. Multiple logistic regression analyses identified the relationship between knee pain during gait and the 4 phenotypes, adjusted for possible risk factors, including age, sex, body mass index, K/L grade, and gait velocity. RESULTS: Multiple logistic regression analysis showed that varus thrust without varus alignment was associated with knee pain during gait (odds ratio [OR] 3.30, 95% confidence interval [95% CI] 1.08-12.4), and that varus thrust combined with varus alignment was strongly associated with knee pain during gait (OR 17.1, 95% CI 3.19-320.0). Sensitivity analyses applying alternative cutoff values for defining static varus alignment showed comparable results. CONCLUSION: Varus thrust with or without static varus alignment was associated with the occurrence of knee pain during gait. Tailored interventions based on individual malalignment phenotypes may improve clinical outcomes in patients with knee OA.

Reference values for toe grip strength among Japanese adults aged 20 to 79 years: a cross-sectional study.

BACKGROUND: No standardised method has been adopted for measuring toe-grip strength (TGS), and no reference values have been established for evaluating it. The present study investigated age-related changes in TGS and the association of TGS with various descriptive characteristics. METHODS: TGS was measured in both feet of 1842 community-dwelling individuals aged 20-79 years using a toe-grip dynamometer. The participants were classified by decade into six age groups: 20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years. Correlations for TGS between the dominant and non-dominant sides were analysed according to decade and sex using Pearson's correlation coefficient. The mean TGS and TGS-to-weight ratio (TGS/Wt%) were compared between sexes by each decade and among all decades by sex using two-way analysis of variance with post-hoc tests. To assess relationships between mean TGS and various descriptive characteristics, we determined Pearson's correlation coefficient by sex and performed a stepwise multiple-regression analysis. Significance was set at 5%. RESULTS: Correlations for TGS between the dominant and non-dominant sides were significant in all decades by sex, ranging from 0.73 for men in their 70s to 0.91 for women in their 50s. Mean TGS and TGS/Wt% significantly differed between the sexes in all decades and in all decades except the 40s, respectively. In men, the mean TGS and TGS/Wt% significantly decreased with aging after the 50s and 60s, respectively. In women, both the mean TGS and TGS/Wt% significantly decreased between the 40s and 50s and between the 60s and 70s. TGS significantly correlated with age, height, and weight in both sexes. The stepwise multiple-regression analysis revealed TGS was significantly associated with sex, age, height, and weight (adjusted R(2) = 0.31). CONCLUSIONS: TGS was closely correlated between the dominant and non-dominant sides. TGS and TGS/Wt were significantly reduced with aging after the 50s in men and significantly reduced between the 40s and 50s and between the 60s and 70s in women. Age, sex, height, and weight accounted for only 30.8% of the variance in TGS. Therefore, other factors (e.g. toe flexibility, structural characteristics) should be considered for improving the accuracy of predicting TGS.