Post-hip-fracture knee pain in older adults prolongs their hospital stays: A retrospective analysis using propensity score matching.

BACKGROUND AND PURPOSE: Post-hip-fracture knee pain (PHFKP) occurs in ∼28%-37% of patients and contributes to a prolonged length of hospital stay (LOS). Analyses of LOS prolongation due to PHFKP have been limited to univariate analyses that do not consider important confounding factors. After adjusting for important confounding factors, we investigated whether the presence or absence of PHFKP makes a difference in LOS in patients with hip fractures. METHODS: We conducted a retrospective review of the medical records of patients who had undergone postoperative rehabilitation after surgery for a hip fracture. Demographic and clinical information, discharge parameters, and PHFKP development information were collected from the medical records. Using propensity score matching, we performed a two-group comparison of LOS, the functional independence measure (FIM) motor score (FIMm), FIMm gain, and FIMm effectiveness in patients with and without PHFKP. Six variables were included in the calculation of propensity scores: age, sex, body mass index, fracture type, American Society of Anesthesiologists physical status, and independence in activities of daily living at discharge. One-way analysis of variance was used to examine the details of the relationships between LOS and (i) the time of PHFKP development and (ii) pain intensity. RESULTS: We analyzed the cases of 261 patients, of whom 87 (33.3%) developed PHFKP. In propensity score matching, 80 patients were each matched to a patient in the PHFKP or non-PHFKP group. After propensity score matching, a between-group comparison revealed that the PHFKP group had a longer LOS (+11 days) than the non-PHFKP group, and there were no differences in FIMm gain or FIMm effectiveness. The timing of PHFKP development and pain intensity were not related to the LOS. DISCUSSION: Even after adjusting for confounders, the development of PHFKP was found to prolong LOS. Clinicians should be aware of possible LOS prolongation in hip fracture patients with PHFKP.

Clinical prediction rules for multi surfaces walking independence using the Berg Balance Scale or Mini-Balance Evaluation Systems Test in persons with stroke.

BACKGROUND: A Clinical prediction rule (CPR) for determining multi surfaces walking independence in persons with stroke has not been established. OBJECTIVES: To develop a CPR for determining multi surfaces walking independence in persons with stroke. METHODS: This was a multicenter retrospective analysis of 419 persons with stroke. We developed a Berg Balance Scale (BBS)-model CPR combining the BBS, comfortable walking speed (CWS) and cognitive impairment, and a Mini-Balance Evaluation Systems Test (Mini-BESTest)-model CPR combining the Mini-BESTest, CWS, and cognitive impairment. A logistic regression analysis was conducted with multi surfaces walking independence as the dependent variable and each factor as an independent variable. The identified factors were scored (0, 1) based on reported cutoff values. The CPR's accuracy was verified by the area under the curve (AUC). We used a bootstrap method internal validation and calculated the CPR's posttest probability. RESULTS: The logistic regression analysis showed that the BBS, CWS, and cognitive impairment were factors in the BBS model, and the Mini-BESTest was a factor in the Mini-BESTest model. The CPRs were 0-3 points for the BBS model and 0-1 points for the Mini-BESTest model. The AUCs (bootstrap mean AUC) of the CPR score were 0.89 (0.90) for the BBS model and 0.72 (0.72) for the Mini-BESTest model. The negative predictive value (negative likelihood ratio) was 97% (0.054) for CPR scores < 2 for the BBS model and 94% (0.060) for CPR scores < 1 for the Mini-BESTest model. CONCLUSIONS: The CPR developed herein is useful for determining multi surfaces walking independence.

Clinical Prediction Models for Nonmortality Outcomes in Older Adults With Hip Fractures: A Systematic Review.

BACKGROUND: Several hip fracture clinical prediction models have been developed. We conducted this study to (i) map outcomes used in clinical prediction models for hip fracture, (ii) identify the domains and instruments of predictors, and (iii) assess the risk of bias. METHODS: We performed systematic searches of studies published from June 2002 to June 2023 in the PubMed, Cochrane Library, CINAHL, CiNii, and Ichushi databases. After the relevant articles were identified, we performed the data extraction and bias risk assessment. We used the Prediction Study Risk Of Bias Assessment Tool (PROBAST) to assess each study's risk of bias. Outcome mapping was performed for the core outcome set of hip fractures. Qualitative synthesis and the PROBAST evaluation were performed on other-than-mortality core outcomes, which are difficult to target in rehabilitation. RESULTS: We screened 3 206 studies for eligibility; 45 studies were included in the outcome mapping, and 10 studies were included in the qualitative synthesis. Outcomes included mortality (n = 35), mobility (n = 8), and activities of daily living (n = 2). No clinical prediction models had pain or health-related quality of life as an outcome. Predictors were reported in 8 domains and 38 measures. The PROBAST evaluation showed a high risk of bias in all 10 studies that were eligible for a qualitative synthesis. CONCLUSIONS: The clinical prediction models had only mortality, mobility, and activities of daily living as outcomes. The development of clinical prediction models with pain and health-related quality of life as outcomes is necessary. Clinical prediction models overcoming the risk of bias identified in this study are also needed.

Predictors of post-hip fracture knee pain in hospitalized older adults with intertrochanteric femoral fracture.

BACKGROUND: Post-hip fracture knee pain (PHFKP) is an important issue that contributes to reduced gait speed and prolonged hospitalization. Femoral morphology has been reported to contribute to the development of PHFKP, but an independent association has not been confirmed and clinically applicable cutoffs for predicting the development of PHFKP remain unclear. OBJECTIVE: To determine whether femoral morphology and knee extension range of motion limitation are independent factors in PHFKP and to determine cutoffs for predicting the development of PHFKP. DESIGN: Retrospective chart review study. SETTING: Convalescent inpatient rehabilitation hospital. PARTICIPANTS: Patients in a convalescent ward after intertrochanteric femoral fracture surgery. MAIN OUTCOME MEASURES: PHFKP development, radiographic femoral morphology (leg length discrepancy and neck-shaft angle), and knee extension range of motion limitation. RESULTS: PHFKP developed in 36 (35%) of the 103 patients enrolled. The PHFKP group had a longer hospital stay (p = .029), greater weight (p = .031), greater knee extension range of motion limitation (p = .001), and more varus neck-shaft angle (p < .001) compared to the non-PHFKP group. Varus neck-shaft angle (odds ratio, 0.85; 95% confidence interval [CI], 0.78-0.92; p < .001) and knee extension range of motion limitation (odds ratio, 1.18; 95% CI, 1.07-1.30; p = .001) were significant factors for PHFKP development. Neck-shaft angle discrepancy and knee extension range of motion limitation demonstrated moderate accuracy in discriminating development of PHFKP according to receiver operating characteristic analysis, with cutoffs of 9.6° and 7.5°, respectively. Areas under the receiver operating characteristic curve were 0.77 (95% CI, 0.66-0.88; p < .001) for neck-shaft angle discrepancy and 0.67 (95% CI, 0.56-0.79; p = .004) for knee extension range of motion limitation. CONCLUSIONS: Varus neck-shaft angle and knee extension range of motion limitation were identified as independent predictors of PHFKP. The cutoff for neck-shaft angle may be useful for predicting PHFKP development and to define an acceptable angle of fracture reduction to prevent PHFKP.

Sleep Should Be Focused on When Analyzing Physical Activity in Hospitalized Older Adults after Trunk and Lower Extremity Fractures-A Pilot Study.

Although the importance of resting in bed for hospitalized older adults is known, current methods of interpreting physical activity (PA) recommend the use of a broad definition of sedentary behavior (SB) that includes 0−1.5 metabolic equivalents (METs) of sleep (SL) and sitting. We investigated the characteristics of PA by conducting a cross-sectional study of 25 older adults with trunk and lower extremity fractures. The intensity of their PA was interpreted as SL (0−0.9 METs), SB (1−1.5 METs), low-intensity PA (LIPA: 1.6−2.9 METs), and moderate-to-vigorous PA (MVPA: >3.0 METs). We calculated the correlation coefficients to clarify the relationship between each PA intensity level. Our analyses revealed that the PA time (min/day) was accounted for by SB (53.5%), SL (23.2%), LIPA (22.8%), and MVPA (0.5%). We observed negative correlations between SL and SB (r = −0.837) and between SL and LIPA (r = −0.705), and positive correlations between SB and LIPA (r = 0.346) and between LIPA and MVPA (r = 0.429). SL and SB were also found to have different trends in relation to physical function. These results indicate that SL and SB are trade-offs for PA during the day. Separate interpretations of the SL and SB of older hospitalized adults are thus recommended.

Survey with Innovations to Increase Response Rate Reveals Low Compliance with Guidelines among Youth Baseball Coaches - Including a Survey of Differences between Cities.

Background: Compliance rates of youth baseball team coaches with guidelines regarding pitch count limits have been reported, but response rates from previous surveys have not been high, which may introduce substantial non-response bias. In addition, differences between cities in guideline compliance rates have remained unclear. Purpose: The aim of the present study was to obtain data on coach compliance with guidelines for pitch count limits with a high survey response rate. Secondary aims were to determine compliance with guidelines other than pitch count limits, and to determine whether differences in compliance exists between cities. Methods: A questionnaire was developed for coaches of youth baseball teams in Gunma to assess knowledge of and compliance with the Japan Softball Baseball Association's recommendations for preventing injuries. In the preparation, distribution, and collection of the questionnaire, four strategies were applied to increase the response rate. The questionnaire surveyed basic descriptive information about the team and coach and coaches compliance with guidelines. Survey items were compared between compliant and non-compliant groups for pitch count limits, and by city. Results: Valid responses to the questionnaire were obtained from coaches of 58 of 62 teams surveyed for a response rate of 93.5%. Despite the fact that almost all coaches were aware of the recommendations regarding pitch count limits and felt these limits were needed, only 15.5% were compliant. For guidelines other than the pitch count limits, the recommended values were exceeded for practice time on holidays. Differences between cities were evident in the compliance rate with the pitch count limit, but no differences between cities in other items were observed. Conclusion: The results of this research revealed that compliance with pitch count limits in this sample of youth baseball coaches was much lower than previously reported. Differences between cities were identified in rates of compliance with pitch count limits. These results suggest a need to increase compliance rates with guidelines for pitch count limits and to address differences between cities. Level of Evidence: Cross-sectional survey study, 3b.

Measurement of physical activity and prevention of physical inactivity/sedentary behaviors in patients with septic knee arthritis before and after hospital discharge: A case report.

BACKGROUND: Patients with septic knee arthritis tend to have prolonged pain, which may lead to a decrease in physical activity (PA). Pain catastrophizing, which is associated with chronic pain, is known to be a limiting factor for PA. An objective measurement of PA in patients with septic knee arthritis has not been reported. Here we describe the accelerometry-based measurement of the PA of a patient with septic knee arthritis before and after discharge, and we report the ability of follow-up outpatient physical therapy to increase PA. METHODS: A 70-year-old Japanese woman admitted to the hospital with a diagnosis of left septic knee arthritis presented with prolonged pain and pain catastrophizing in the left knee. We investigated her pre- and post-discharge PA by using an accelerometer. We also investigated her physical function, pain, and pain catastrophizing as a possible influence on PA. Follow-up outpatient physical therapy (consisting of PA feedback, counseling, and reassurance) was performed to improve the patient's physical function and increase her PA. RESULTS: The patient's PA indicated general inactivity from pre-discharge to 1 month post-discharge, especially immediately post-discharge (sedentary behavior [SB]: 540-571.3 min/daytime, light-intensity PA: 145.8-177.8 min/daytime). The follow-up outpatient physical therapy was effective in increasing her physical function and PA (a 31-min decrease in SB, a 32-min increase in light-intensity PA) but was not effective in reducing her pain or pain catastrophizing. DISCUSSION: Contrary to the general trend, this patient showed a decrease in PA after hospital discharge compared to PA during hospitalization. Follow-up outpatient physical therapy had the effect of increasing the patient's PA, which was decreased immediately post-discharge.

Rasch Validation and Comparison of the Mini-BESTest and S-BESTest in Individuals With Stroke.

OBJECTIVE: The purpose of this study was to compare the psychometric properties of the Mini-Balance Evaluation Systems Test (Mini-BESTest) and S-BESTest and to evaluate which is more suitable for use in clinical settings for individuals with stroke. METHODS: This multicenter retrospective cross-sectional study investigated 115 individuals with stroke (mean age, 70.8 y [SD = 11.2 y]) who were able to stand without physical assistance. All individuals were examined with the BESTest and with the Mini-BESTest and S-BESTest scored based on the BESTest results. The data were analyzed using a Rasch analysis (partial credit model). RESULTS: The Mini-BESTest results revealed a correctly functioning rating scale, good fit of the data to the model (apart from 1 overfit item), good reliability for both persons and items (6 statistically detectable levels of balance ability), local dependence between 1 item pair, and essential unidimensionality. The S-BESTest results demonstrated disordered rating scale thresholds (1 response option required collapsing), good fit of the data to the model (apart from 1 underfit item), good reliability for both persons and items (5 statistically detectable levels of balance ability), local dependence between 2 item pairs, and essential unidimensionality. CONCLUSION: The analyses confirmed that the reliability of the S-BESTest was good and unidimensional and that the test provides several improved points, such as item redundancy and local independence of items. Nevertheless, the Mini-BESTest results supported previous findings as a whole and were better than those from the S-BESTest. IMPACT: Rasch analysis demonstrated that the Mini-BESTest was a better balance assessment scale than the S-BESTest for individuals with stroke based on its psychometric properties. The Mini-BESTest may serve as a useful scale for assessing balance in individuals with stroke, and a keyform plot and strata may help clinical decision-making in terms of interpreting scores and goal setting.

Which Balance Evaluation Systems Test sections best distinguish levels of post-stroke functional walking status?

OBJECTIVE: To determine which sections of the Balance Evaluation Systems Test (BESTest) distinguish levels of post-stroke functional walking status and to establish their cut-off scores. DESIGN: A retrospective cross-sectional study. SUBJECTS AND METHODS: The BESTest was administered to 87 stroke patients who were able to walk without physical assistance upon discharge from the hospital. Subjects were divided into 3 functional walking status groups: namely, household ambulators, limited community ambulators, and unlimited community ambulators. The receiver operating characteristic curve was determined and the cut-off score and area under the receiver operating characteristic curve (AUROC) of each section calculated. RESULTS: In the comparison of household and limited community ambulators, the accuracies of all BESTest sections were moderate (AUROC>0.7), and the cut-off scores were 36.1-78.6%. In the comparison of limited and unlimited community ambulators, one section (stability in gait) had high accuracy (AUROC=0.908, cut-off scores=73.8%) and 3 sections (biomechanical constraints, anticipatory postural adjustments, and postural response) had moderate accuracy (AUROC=0.8120-0.834, cut-off scores=75.0-83.4%). CONCLUSION: This study demonstrated that different sections of the BESTest had different abilities to discriminate levels of post-stroke functional walking status, and identified cut-off values for targeted improvement.

Inpatient knee pain after hip fracture surgery affects gait speed in older adults: A retrospective chart-referenced study.

AIM: Post-hip fracture knee pain (PHFKP) develops in 28-37.4% of patients with hip fracture and contributes to prolonged hospitalization. Although reduced balance and gait speed contribute to falls, the effects of PHFKP remain unclear. This study aimed to clarify whether PHFKP is a factor in balance and gait speed. METHODS: We retrospectively reviewed the medical records of patients after hip fracture. Development of PHFKP, basic information, and physical function were examined. Berg balance scale (BBS) and maximum walking speed (MWS) were collected at discharge. These parameters were compared with the presence or absence of PHFKP. In addition, multiple analyses were conducted with BBS and MWS as dependent variables and PHFKP as one of the independent variables. RESULTS: Of the 146 patients enrolled, 43 (29.5%) developed PHFKP, and 37.2% of patients with PHFKP showed residual symptoms at discharge. Intensity of PHFKP was mostly mild to moderate. The PHFKP group showed an extended length of stay (+13.3 days) and a tendency toward more discharges to facilities compared with the control group. Knee extension range of motion limitation, knee extensor strength, and BBS did not differ between groups, while MWS was significantly lower in the PHFKP group (0.85 ± 0.32 m/s vs. 1.07 ± 0.39 m/s). Multiple analyses showed that development of PHFKP was not associated with BBS, but was associated with decreased MWS (standardized beta = -0.202, P = 0.005). CONCLUSIONS: PHFKP was identified as an independent factor in gait speed decline. PHFKP patients should be monitored for reduced gait speed during rehabilitation. Geriatr Gerontol Int 2021; 21: 830-835.

Femoral morphology is associated with development of knee pain after hip fracture injury among older adults: A nine-year retrospective study.

INTRODUCTION: We aimed to clarify differences in femoral morphology associated with post-hip fracture knee pain (PHFKP). METHODS: Medical records and radiographic examinations were retrospectively reviewed to determine the relationship between PHFKP development and femoral morphology. Leg length discrepancy (LLD) and neck-shaft angle discrepancy (NSAD) were measured from hip radiographs. RESULTS: 202 were enrolled, of whom 64 (31.7%) developed PHFKP. The PHFKP group showed more varus NSA. Intertrochanteric femoral fractures (γ-nail or CHS) displayed a more varus NSA. CONCLUSIONS: Femoral morphology (varus NSA) may be involved in the development of PHFKP.

Biomechanical analysis of the pitching characteristics of adult amateur baseball pitchers throwing standard and lightweight balls.

[Purpose] The purpose of this study was to determine the relationship between pitching weight and pitching mechanics, including ball reaction force (BRF) and temporal parameters, for the prevention of throwing injury in adult amateur pitchers. [Participants and Methods] Twenty adult male amateur pitchers (mean age, height, and body mass: 26 ± 3.4 years, 1.7 ± 0.03 m, and 71.6 ± 9.5 kg, respectively) randomly pitched light (110 g) and heavy (145 g) baseballs at maximum velocity. Kinematic, kinetic, and temporal parameters were compared between the light and heavy balls. [Results] Pitching heavy balls significantly increased the BRF to 9.2 N and maximum trunk rotation angular velocity to 26.2°/sec, and decreased the ball speed to 1.4 m/sec and upper limb joint torque efficiency and shoulder internal rotation angular velocity at the moment of ball release at 250.8°/sec. Furthermore, the peak temporal kinetic parameters until ball release appeared early in the throwing of the heavy ball. [Conclusion] Adult amateur pitchers who pitched heavy balls had greater BRF; had decreased upper limb joint torque efficiency, ball speed, and arm angular velocity; and reached maximum kinetics early. Adult amateur pitchers may be at risk of throwing injuries due to throwing of heavy balls.

Comparing the measurement properties and relationship to gait speed recovery of the Mini-Balance Evaluation Systems Test and the Berg Balance Scale in ambulatory individuals with subacute stroke.

OBJECTIVES: Although the Mini-Balance Evaluation Systems Test (Mini-BESTest) is known to be a reliable and valid measure of balance in individuals with stroke, the utility of this tool in relation to subacute stroke walking speed and the recovery of gait ability has not been explored. Here, we compared the measurement properties and their relationship to gait speed on the Mini-BESTest and the Berg Balance Scale (BBS) in middle and older ambulatory individuals with subacute stroke, and we investigated which balance assessment tool is more likely to capture the status of the recovery of gait speed. METHODS: We retrospectively analyzed the cases of 88 individuals 50 years or older with stroke who had been evaluated using the Mini-BESTest by using the BBS and by assessing their comfortable walking speed (CWS). The proportion of subjects who showed improvement was calculated for 34 stroke survivors from data obtained at admission to and discharge from the hospital. RESULTS: Compared with the BBS, the Mini-BESTest showed a better distribution of total scores without a ceiling effect. The two scales showed correlations with gait speed (Mini-BESTest: r=0.702; BBS: r=0.592) and discrimination between fast and slow walkers. The responsiveness of the Mini-BESTest was excellent, with an area under the curve of 0.894, thus discriminating between gait speed improvement versus non-improvement. CONCLUSIONS: These results indicate that the Mini-BESTest is more useful than the BBS in terms of its measurement properties and ability to measure gait recovery in middle and older ambulatory individuals with subacute stroke.

Comparison of the structural validity of three Balance Evaluation Systems Test in older adults with femoral or vertebral fracture.

OBJECTIVE: To clarify and compare the structural validity of 3 Balance Evaluation Systems Tests (BESTest, Mini-BESTest, and Brief-BESTest) in older adults with femoral or vertebral fractures. DESIGN: Cross-sectional study. SUBJECTS: Ninety-four older adults (age ?65 years) with femoral or vertebral fractures, who could walk without physical assistance. METHODS: Four BESTest models (BESTest, one-factor Mini-BESTest, four-factor Mini-BESTest, and Brief-BESTest) were examined using confirmatory factor analysis, and the models goodness-of-fit was assessed. Unidimensionality of the best-fitting model was confirmed by Rasch principal component analysis on the residuals. RESULTS: Confirmatory factor analysis showed that the four-factor Mini-BESTest model (comparative fit index?=?0.952; Tucker-Lewis index?=?0.937; root-mean square error of approximation?=?0.060; standardized root-mean-square residual?=?0.062) has a better structure than other models. The principal component analysis of standardized residuals showed that the variance attributable to Rasch factor was good, with eigenvalues <2, confirming the factors unidimensionality. CONCLUSION: The four-factor Mini-BESTest model shows good structural validity in older adults with femoral or vertebral fracture. Evaluating dynamic balance by focusing on 4 components (anticipatory postural adjustments, postural responses, sensory orientation, and stability in gait) may help therapists in making clinical decisions.

Structural validity of Balance Evaluation Systems Test assessed using factor and Rasch analyses in patients with stroke.

[Purpose] The Balance Evaluation Systems Test (BESTest) is a comprehensive assessment tool, although it is not confined for use in stroke patients. This study aimed to determine the structural validity of the BESTest in self-ambulatory patients with stroke using both factor and Rasch analyses. [Participants and Methods] This retrospective study included 140 self-ambulatory patients with stroke. The structural validity of the BESTest was analyzed according to principal component, exploratory factor, Rasch, confirmatory factor, and correlation analyses. [Results] The analytical results supported a four-factor model comprising 25 items. The four factors included dynamic postural control with gait, static postural control, stepping reaction, and stability limits in sitting. Evidence of high structural validity and reliable internal consistency suggested that the 25-item BESTest is valid and reliable. Each factor was significantly correlated with lower extremity motor function and walking ability. [Conclusion] Eleven items in the BESTest were poorly correlated, and the remaining 25 items were grouped into four factors that demonstrated good structural validity for patients with stroke. Further studies should validate the applicability of the 25-item BESTest four-factor model in a larger sample of patients with stroke in a clinical setting.

Prediction of falling risk after discharge in ambulatory stroke or history of fracture patients using Balance Evaluation Systems Test (BESTest).

[Purpose] The purpose of this study was to clarify the relationships between falls and sections of the Balance Evaluation Systems Test (BESTest) in patients with stroke or those with a history of fracture. [Subjects and Methods] This longitudinal study included 51 self-ambulatory inpatients. Balance was assessed 1 week prior to discharge using the BESTest, and the incidence of falls within 6 months after discharge was investigated. Relationships between falling and balance components were analyzed using the t-test or the Mann-Whitney U test and receiver operating characteristic (ROC) curve analysis. [Results] Five subjects were dropped out before follow-up at 6 months. Falls were reported by 10 of the remaining 46 participants. Scores for two sections (Anticipatory Postural Adjustments and Sensory Orientation) were significantly lower in fallers than in non-fallers with stroke. Four of the six sections (Biomechanical Constraints, Anticipatory Postural Adjustments, Sensory Orientation, and Stability in Gait) showed areas under the ROC curves >0.8 (0.82, 0.83, 0.84, and 0.81, respectively). In patients with a history of fractures, all sections were not significantly different between fallers and non-fallers. [Conclusion] Anticipatory Postural Adjustments and Sensory Orientation sections of the BESTest were related to future occurrence of fall after discharge in self-ambulatory stroke patients.

Correlation of upper limb joint load withsimultaneous throwing mechanics including acceleration parameters in amateur baseball pitchers.

[Purpose] The purpose of this study was to provide information regarding the knowledge of mechanical principles related to the load applied to the shoulder and elbow during the pitching motion. [Subjects and Methods] The three-dimensional kinematics of body segments were measured in 19 amateur baseball players with a VICON motion capture system. The correlation between maximum shoulder internal torque, maximum elbow varus torque, and simultaneous kinematic parameters including joint angular acceleration and ball acceleration was investigated. [Results] Peak shoulder internal rotation torque and elbow varus torque averaged 31 Nm and 26 Nm, respectively. Ball acceleration had the strongest influence on shoulder internal rotational torque (standardized partial regression coefficient 0.69). During previous maximum external rotation (pre-MER), the main cause parameter of elbow varus torque was shoulder horizontal adduction velocity (r=0.672). On the other hand, after MER (post-MER), the main cause was ball acceleration (r=0.745). [Conclusion] Results of our study suggest that one of the main mechanical principles of joint load during the baseball pitching motion may be the 'inertia' yielded on the segment distal to the certain joint.