Differences in lower-limb biomechanics during single-leg landing considering two peripheral fatigue tasks.

Dynamic knee valgus (DKV) occurs during landing after a fatigue task involving the lower extremity. However, the manner in which different peripheral fatigue tasks affect DKV remains unknown. In this study, we investigated the DKV via electromyography during single-leg landing considering the hip-joint fatigue task (HFT) and knee-joint fatigue task (KFT) performed by healthy men. We recruited 16 healthy male participants who performed a single-leg jump-landing motion from a height of 20 cm before and after an isokinetic hip abduction/adduction task (HFT) and knee extension/flexion task (KFT). Three-dimensional motion analysis systems were attached to the left gluteus medius and quadriceps, and surface electromyography was used to analyze the lower limb kinematics, kinetics, and muscle activity. The primary effects and interactions of the task and fatigue were identified based on the two-way repeated-measures analysis of variance. The results of the average angle during landing indicated that DKV occurs in KFT, whereas HFT applies external forces that adduct and internally rotate the knee at peak vertical ground reaction force (vGRF). Furthermore, both KFT and HFT exhibited an increase in muscle activity in the quadriceps. The analysis revealed that the occurrence of DKV varies depending on the peripheral fatigue task, and the effects on average DKV during landing and DKV at peak vGRF vary depending on the peripheral fatigue task.

Kinematic effects of lateral wedged insoles in patients with medial knee osteoarthritis.

[Purpose] To examine the effect of lateral wedged insoles on the rotation mechanism of the knee joint in patients with knee osteoarthritis. [Participants and Methods] The participants included 11 patients with medial knee osteoarthritis. We asked all participants to stand up from a 40-cm-high chair, and we measured the rotation angle of the knee joint during the movement. The standing motion was performed under four conditions: barefoot and with 7-, 10-, and 13-mm lateral wedged insoles. We also measured four healthy participants as controls for comparison. [Results] During the standing motion, we internally rotated the tibia relative to the femur. In healthy participants, we measured 19.6° internal rotation of the tibia relative to the femur. Patients with knee osteoarthritis had internal rotations of approximately 9.8° when barefoot and 7.1°, 6.4°, and 7.1° when wearing lateral wedged insoles of 7, 10, and 13 mm, respectively. [Conclusion] Lateral wedged insoles do not modify the knee joint rotation motion of patients with knee OA to the correct style.

Influence of time from injury to surgery on knee biomechanics during walking in patients with anterior cruciate ligament reconstruction.

The pilot study aimed to determine whether the time from injury to surgery influences on postoperative knee biomechanics during walking in patients with anterior cruciate ligament reconstruction (ACLR). Thirty-two patients with unilateral ACLR (early, 10 patients; delayed, 22 patients) and 30 control subjects participated in this study. All examinations for patients with ACLR were performed preoperatively and at 12 months postoperatively and comprised passive knee joint laxity, knee muscle strength, and knee kinematics and kinetics during walking. At both time points, there were no significant differences in passive knee joint laxity and knee muscle strength between the early ACLR and delayed ACLR groups. Preoperatively, both the early ACLR and delayed ACLR patients exhibited significantly reduced knee extension movement from midstance to terminal stance compared to the control subjects. Moreover, the delayed ACLR patients exhibited significantly decreased peak external knee flexion moment compared to the control subjects. At 12 months postoperatively, the early ACLR patients showed significant improvement in knee extension movement from midstance to terminal stance compared to pre-ACLR, while the delayed ACLR patients did not show significant improvement in this knee extension movement. It can be concluded that early ACLR may be more beneficial to improve knee biomechanics during walking.

Effects of Physiatrist and Physiotherapist-supervised Therapeutic Exercise on Physical Function in Frail Older Patients with Multimorbidity.

Objectives: : To ease the burden on care facilities, there is a need to reduce the number of frail older people with multiple chronic and non-communicable diseases (multimorbidity) that require long-term care. We investigated the effects of therapeutic exercise in rehabilitation treatment for older individuals with frailty and multimorbidity. Methods: : We performed 4 weeks of inpatient rehabilitation treatment for frail older patients with multimorbidity. The therapeutic exercise was performed based on whole-body evaluations by qualified physiatrists and physiotherapists. Sixty-minute sessions were conducted twice a day and six times a week in accordance with the American College of Sports Medicine guidelines. Physical functions (grip strength, isometric lower muscle strength, 10-m walking test, and 6-min walking test) were measured at admission and discharge. Results: : Of the 33 patients, 8 were unable to complete physical function evaluations, and 1 patient had a stress fracture of the right calcaneus beyond the rehabilitation time. Twenty-four patients were included in the analysis. Compared to the admission period, significant improvements were observed for all evaluated parameters post-therapy (P < 0.05). However, no significant correlation was found between the number of chronic diseases and changes to physical function (P > 0.05). Conclusions: : Physical function of frail older individuals with multimorbidity improves through rehabilitation treatments supervised by physiatrists and physiotherapists. The number of chronic illnesses and the improvements in physical function were not related. Therefore, rehabilitation treatments for older patients may target both frailty and multimorbidity. Our results will aid in the rehabilitation treatment plans for this demographic.

A cross-sectional survey of consistent rehabilitation through long-term care insurance in Japan: a questionnaire survey.

There seems to be a lack of consistency of maintenance/community-based rehabilitation through long-term care insurance. We aimed to clarify whether consistent rehabilitation can be performed through long-term care insurance by questionnaires. Materials and Methods: This study was a cross-sectional study in a nationwide survey among rehabilitation staff and care recipients who completed disease-specific rehabilitation and required maintenance/community-based rehabilitation through long-term care insurance. Consistency of rehabilitation was compared using Fisher's exact tests. The concordance of the rehabilitation evaluation and treatment conducted under medical and long-term care insurance was assessed using the κ coefficient. Results: Six hundred questionnaires from care recipients and staff were analyzed. Of the rehabilitation staff, 264 (44%) obtained rehabilitation plans from medical institutions. There was a significant difference between the responses of "referral from the same medical corporation" and "obtaining the rehabilitation plan" by Fisher's exact test (odds ratio: 3.242; P<0.001). Most rehabilitation treatments under medical insurance comprised walking or training with parallel rods/canes [498 patients (83%)], and 454 patients (76%) received stretching and range-of-motion training for the limbs and spine for long-term care insurance. Muscle strength evaluation was the most frequently conducted under medical and long-term care insurance [383 (73%) and 487 (83%), respectively]. The concordance of the evaluation and treatment content, except for disease-specific evaluation, was low (κ coefficient≤0.6). Conclusions: The rate of provision of rehabilitation plans was low, and evaluation and treatment content under medical and long-term care insurance was inconsistent. Our results draw attention to the need for consistent rehabilitation plans between disease-specific and maintenance/community-based rehabilitation.

Case report: Physical findings, physical therapy practice, and characteristics of disability of activities of daily living caused by obturator nerve palsy after neurotmesis.

The obturator nerve originates from the lumbar plexus and innervates sensation in the thigh and movement of the adductor muscle group of the hip. Reports on physical therapy for patients with obturator nerve injuries have been limited due to insufficient injuries, and there have been no reports on rehabilitation after neurotmesis. Furthermore, there are no reports on the status of activities of daily living (ADL) and details of physical therapy in patients with paralysis of the adductor muscle group. In this study, we reported on a patient with adductor paralysis due to obturator neurotmesis, including the clinical symptoms, characteristics of ADL impairment, and effective movement instruction. The patient is a woman in her 40's who underwent laparoscopic total hysterectomy, bilateral adnexectomy, and pelvic lymph node dissection for uterine cancer (grade-2 endometrial carcinoma). During pelvic lymph node dissection, she developed an obturator nerve injury. She underwent nerve grafting during the same surgery by the microsurgeon. Donor nerve was the ipsilateral sural nerve with a 3-cm graft length. Due to obturator nerve palsy, postoperative manual muscle test results were as follows: adductor magnus muscle, 1; pectineus muscle, 1; adductor longs muscle, 0; adductor brevis muscle, 0; and gracilis muscle, 0. On postoperative day 6, the patient could independently perform ADL; however, she was at risk of falling toward the affected side when putting on and taking off her shoes while standing on the affected leg. The patient was discharged on postoperative day 8. Through this case, we clarified the ADL impairment of a patient with adductor muscle palsy following obturator neurotmesis, and motion instruction was effective as physical therapy for this disability. This case suggests that movement instruction is important for acute rehabilitation therapy for patients with hip adductor muscle group with obturator neurotmesis.

Detecting side-to-side differences of lower limb biomechanics during single-legged forward landing after anterior cruciate ligament reconstruction.

BACKGROUND: Motion analysis can be used to evaluate functional recovery after anterior cruciate ligament (ACL) reconstruction; however, the biomechanics parameters of the lower limb that are specifically altered in ACL-reconstructed knees compared to the contralateral side are not well understood. This retrospective study aimed to compare side-to-side differences in lower limb biomechanics during the first 100 milliseconds (ms) after initial contact in a single-leg forward landing task. METHODS: Using three-dimensional motion analysis, lower joint kinematic and kinetic variables were measured 8-10 months postoperatively in 22 patients who had undergone ACL reconstruction. We determined side-to-side differences in lower limb biomechanics over the 100-ms timeframe after landing, and receiver operating characteristic (ROC) curve analyses were performed to calculate the area under the curve (AUC) for parameters showing significant side-to-side differences. RESULTS: During the 100-ms timeframe after landing, 58 kinematic and kinetic items showed significant side-to-side differences. Side-to-side differences in lower limb biomechanics over the 40-ms timeframe after landing existed. The ROC curve analysis identified 11 items with AUC values ≥ 0.70, including hip flexion, abduction moment, and knee joint power, and their AUC values were not significantly different. CONCLUSION: Hip flexion/abduction moment and knee power after GRF max could be used as outcomes for assessing functional recovery in patients who have undergone ACL reconstruction.

Rehabilitation in the long-term care insurance domain: a scoping review.

PURPOSE: Since the enactment of the long-term care insurance (LTCI) act in 2000, the number of LTCI users has increased annually. However, evidence regarding what is being carried out as rehabilitation treatment under LTCI is lacking. In this study, a scoping review was performed to bridge this knowledge gap. METHODS: Articles related to rehabilitation in connection with LTCI published between April 2000 and November 2020 were searched for in PubMed, CINAHL, CENTRAL (Cochrane Central Register of Controlled Trials), Ichushi Web Ver.5, and CiNii and randomized controlled trials (RCTs) of rehabilitation provided under LTCI were examined. RESULTS: Of the 15,572 publications identified, 15 RCTs, including rehabilitation treatment by physiatrists and therapists, met the eligibility criteria of our review and were included. The rehabilitation trials in the 15 RCTs varied and included balance training, exercise therapy, cognitive tasks, and activities such as singing and dancing. The results allowed us to focus on three categories: fall prevention, dementia, and theory and tools interventions related to occupational therapy practice. CONCLUSION: The focal points of attention in the rehabilitation treatment of LTCI were identified. However, the physical function, quality of life, and activities of daily living (ADL) of those who "need support" vary from person to person. Therefore, the consolidation of evidence on rehabilitation treatment of LTCI must be continued.

Factors associated with dynamic knee valgus angle during single-leg forward landing in patients after anterior cruciate ligament reconstruction.

BACKGROUND: A few studies have reported on how to predict increased dynamic knee valgus angle (KVA), a risk factor for second anterior cruciate ligament (ACL) injury after ACL reconstruction. This study aimed to identify the factors with the potential to predict the KVA during single-leg hop landing. METHODS: Using three-dimensional motion analysis systems, knee motion during a single-leg hop landing task was measured in 22 patients who had undergone ACL reconstruction at 8-10 months postoperatively. The KVA at initial contact (IC) and maximum KVA during the 40-ms period after IC were calculated using the point cluster technique; correlations between the KVA and other factors were assessed. We performed multiple regression analysis to determine whether KVA could be predicted by these parameters. RESULTS: The KVA was significantly negatively correlated with the static femorotibial angle (FTA; P < 0.01) and patient height (P < 0.01). It was positively correlated with the body mass index (P < 0.05). Multiple regression analysis showed that a small FTA could predict the KVA at IC (ß: 0.52, 95% confidence interval (CI): 2.24-(-0.42); P < 0.01). The maximum KVA during the 40-ms period after IC was associated with the FTA (ß: 0.46, 95% CI: 2.22-(-0.26); P = 0.02) and height (ß: 0.40, 95% CI: 0.59-(-0.02); P = 0.04). CONCLUSION: At 8-10 months after ACL reconstruction, the KVA was significantly correlated with the FTA, with reduced FTA being associated with an increased dynamic KVA during single-leg hop landing. The measurement of anatomical parameters may aid in predicting the second ACL injury risk after reconstruction.

Total knee arthroplasty for patients with medial knee osteoarthritis improves trunk movement during gait.

BACKGROUND: Previous studies have indicated that the kinematics of the knee joint affect the trunk and pelvis during gait. However, the factors that influence trunk movement in knee osteoarthritis patients during gait after surgery remain unclear. OBJECTIVE: To examine the effect of total knee arthroplasty (TKA) on trunk movement during gait by comparing knee osteoarthritis patients with healthy controls. METHODS: Fourteen medial knee osteoarthritis patients who underwent initial unilateral TKA and 11 controls participated in this study. Knee and hip joint flexion and trunk and pelvic tilts during gait were acquired using a three-dimensional motion analysis system. Knee joint range of motion, pain, and kinematic data were collected preoperatively and 1 year postoperatively for knee osteoarthritis patients. RESULTS: Knee extension limitation and pain significantly improved postoperatively compared with preoperative stages. Preoperatively, the peak anterior trunk tilt during the stance phase was significantly larger in osteoarthritis patients than in controls. The peak anterior trunk tilt during the stance phase was significantly smaller postoperatively than at preoperative stages. CONCLUSIONS: These results suggest that after TKA, the trunk movements of knee osteoarthritis patients were approximately equal to those of controls, with improvement in clinical outcomes such as knee extension limitation and pain.

The Relationship between Knee Biomechanics and Clinical Assessments in ACl Deficient Patients.

The purpose of this study was to clarify the relationship between knee biomechanics and clinical assessments in ACL deficient patients. Subjects included 22 patients with unilateral ACL rupture and 22 healthy controls. Knee kinematics and kinetics during walking and running were examined using a 3-dimensional motion analysis system. The passive knee joint laxity, range of motion of knee joint, and knee muscle strength were also measured. Correlations between the knee kinematic and kinetic data and clinical assessments were evaluated. In the ACL deficient patients, there were no significant relationships between tibial translation during walking and running and passive knee joint laxity. The correlations between knee kinematics and kinetics and range of motion of knee joint were also not significant. Additionally, there were no significant correlations between knee kinematics during walking and knee muscle strength. However, there were several significant correlations between knee kinematics during running and knee muscle strength. The results demonstrate the importance of knee muscle strength for knee kinematics and kinetics during running in ACL deficient patients. Patients with stronger knee muscle strength may demonstrate more nearly normal knee joint movement during dynamic activities such as running.

The relationship between knee muscle strength and knee biomechanics during running at 6 and 12 months after anterior cruciate ligament reconstruction.

BACKGROUND: Knee joint kinematics and kinetics during running recover at 12 months, not 6 months, following anterior cruciate ligament (ACL) reconstruction surgery. Knee muscle strength is a criterion used to assess an individual's readiness to return-to-sports (RTS); however, the relationship between knee muscle strength and knee biomechanics is unclear. This study investigated the relationship between knee muscle strength and dynamic knee biomechanics during running at 6 and 12 months after ACL reconstruction surgery. METHODS: Knee joint kinematics and kinetics during running were analyzed in 21 patients (10 males, 11 females) who underwent ACL reconstruction for a unilateral ACL deficiency. Kinematics and Kinetics were measured by three-dimensional motion analysis system, and Knee flexion angle was calculated using Point cluster technique and internal extension moment was calculated by the inverse dynamics method. Patients were compared to a control group matched by age, height and weight. Isokinetic knee extension and flexion strength in ACL-reconstructed patients were measured at 6 and 12 months postsurgery, by separated gender. RESULTS: Knee flexion angle was significantly lower in ACL patients at 6 months postsurgery compared to the control group (F (2, 62)=5.78, P=0.014). There were significant lower peak knee flexion angles in male groups than female (F (1, 62)=6.33, P<0.01). Knee extension moments were significantly lower in both male and female ACL patients compared to the control group at 6 and 12 months postsurgery (F (2, 62)=12.05, P<0.01(6 months), P=0.034(12 months)), and there were significant correlations with knee extension moments and maximum torque of knee extension/flexion (P<0.05). At 12 months after surgery, knee joint kinematics in ACL patients were restored. Both peak knee angle and knee extension moment were significantly associated with maximum knee extension/flexion torque values in female patients at 12 months postsurgery. CONCLUSIONS: Dynamic knee biomechanics during running were not restored 6 and 12 months after ACL reconstruction both male and female. It is necessary to strengthen knee extension and flexion muscles to restore knee kinetics during running, especially female patients.

Oxygen therapy may worsen the survival rate in rats with monocrotaline-induced pulmonary arterial hypertension.

Although oxygen therapy rapidly improves arterial oxygen saturation in idiopathic pulmonary arterial hypertension, the effects of chronic administration of oxygen are unknown. The purpose of the present study was to investigate the effects of chronic oxygen therapy on the histological changes and survival rate in rats with idiopathic pulmonary arterial hypertension. Idiopathic pulmonary arterial hypertension was induced by monocrotaline injection. The rats were then randomly assigned to receive or not receive oxygen therapy (O2 group and non-O2 group, respectively). The rats in the O2 group were exposed to a high (90%) oxygen environment from day 17 following injection of monocrotaline, when hypoxemia was first observed. The pulmonary arteriole walls were significantly thicker in monocrotaline-injected rats than in saline-injected rats as vehicle on day 19 and were significantly thicker in the rats that received oxygen therapy than in the rats that did not. Right ventricular inflammations were significantly higher in monocrotaline-injected rats than in saline-injected rats on day 19 and were significantly higher in the rats that received oxygen therapy than in the rats that did not. By day 20 after injection of monocrotaline, the survival rate was significantly lower in the rats that received oxygen therapy than in those that did not. Superoxide dismutase activity in the lungs was higher in monocrotaline-injected rats than in saline-injected rats on day 19 after monocrotaline injection and was also higher in the saline-injected rats that received oxygen therapy than in the saline-injected rats that did not. No interaction was detected between monocrotaline injection and oxygen therapy. These results suggest that chronic oxygen therapy worsens the histological changes and survival rate in idiopathic pulmonary arterial hypertension. The fact that degradation of the histological changes and survival rate was accompanied by increase in superoxide dismutase activity suggests that antioxidant capacity may contribute to the degradation.

Validity of motion analysis using the Kinect system to evaluate single leg stance in patients with hip disorders.

BACKGROUND: Abnormal movements during single leg stance in patients with hip disorders could be detected by the Kinect system as well as the three-dimensional motion analysis system. However, validity of the Kinect system to evaluate single leg stance in patients with hip disorders remains unknown. RESEARCH QUESTION: To investigate the concurrent validity of the Kinect system, relative to the VICON three-dimensional system which is considered as the gold standard for motion analysis, to measure trunk and pelvis alignment during single leg stance. To investigate the discriminant validity of the Kinect system between with and without hip disorders. METHODS: For evaluation of the concurrent validity of the Kinect system, the intra-class correlation coefficient (ICC (3,1)) was calculated for the angle of inclination of the pelvis and trunk in 5 healthy individuals. For evaluation of the discriminant validity of the Kinect system, the angle of inclination of the pelvis and trunk during single leg stance were measured in 27 individuals with hip disorders and 100 healthy individuals. Differences in the maximum angle of inclination of the pelvis and trunk were evaluated between hip disorders and healthy individuals using the Mann-Whitney U test. RESULTS: ICC values were between 0.83-0.93 for the pelvic and 0.63-0.81 for the trunk angle, respectively. The maximum trunk inclination angle calculated using the Kinect system was significantly higher in patients with hip disorders than healthy individuals, with no significant between-group difference in the angle of inclination of the pelvis. SIGNIFICANCE: The Kinect system was adequate to detect certain abnormal movements during single leg stance among patients with hip disorders. Therefore, the Kinect system could provide a convenient motion analysis tool for the assessment of patients with hip disorders.

The Acute Effects of Static and Cyclic Stretching on Muscle Stiffness and Hardness of Medial Gastrocnemius Muscle.

This study aimed to clarify the acute effects of static stretching (SS) and cyclic stretching (CS) on muscle stiffness and hardness of the medial gastrocnemius muscle (MG) by using ultrasonography, range of motion (ROM) of the ankle joint and ankle plantar flexor. Twenty healthy men participated in this study. Participants were randomly assigned to SS, CS and control conditions. Each session consisted of a standard 5-minute cycle warm-up, accompanied by one of the subsequent conditions in another day: (a) 2 minutes static stretching, (b) 2 minutes cyclic stretching, (c) control. Maximum ankle dorsiflexion range of motion (ROM max) and normalized peak torque (NPT) of ankle plantar flexor were measured in the pre- and post-stretching. To assess muscle stiffness, muscle-tendon junction (MTJ) displacement (the length changes in tendon and muscle) and MTJ angle (the angle made by the tendon of insertion and muscle fascicle) of MG were measured using ultrasonography at an ankle dorsiflexion angle of -10°, 0°, 10° and 20° before and after SS and CS for 2 minutes in the pre- and post-stretching. MG hardness was measured using ultrasound real-time tissue elastography (RTE). The results of this study indicate a significant effect of SS for ROM maximum, MTJ angle (0°, 10°, 20°) and RTE (10°, 20°) compared with CS (p < 0.05). There were no significant differences in MTJ displacement between SS and CS. CS was associated with significantly higher NPT values than SS. This study suggests that SS of 2 minutes' hold duration significantly affected muscle stiffness and hardness compared with CS. In addition, CS may contribute to the elongation of muscle tissue and increased muscle strength.

Gender differences in the restoration of knee joint biomechanics during gait after anterior cruciate ligament reconstruction.

BACKGROUND: The aim of our study was to evaluate the effects of gender on recovery of knee joint biomechanics over the stance phase of gait after reconstruction of the anterior cruciate ligament (ACL). METHODS: Gait parameters and knee joint kinematics and kinetics were compared in 32 patients (16 male and 16 female) who underwent ACL reconstruction for a unilateral ACL deficiency, with comparison to an age-, height-, and weight-matched Control group. Knee flexion, adduction and tibial rotation angles were measured and knee extension and abduction moment was calculated by inverse dynamics methods. RESULTS: Females exhibited more tibial external rotation, in both the Control and ACL groups (P<0.05), which was not changed after ACL reconstruction. Prior to reconstruction, sagittal plane biomechanics were changed, in both males and females, compared to the Control groups (P<0.05). These abnormal sagittal plane mechanics were recovered at 12months, but not six months post-reconstruction. CONCLUSIONS: We identified gender-based differences in tibial rotation that influenced the kinematics and kinetics of the knee over the stance phase of gait, both pre-operatively and post-ACL reconstruction. Evaluation of biomechanical effects of ACL injury, before and after reconstruction, should be separately evaluated for females and males.

Characteristics of thoracic and lumbar movements during gait in lumbar spinal stenosis patients before and after decompression surgery.

BACKGROUND: Although gait analysis has been previously conducted for lumbar spinal stenosis patients, the vertebral segmental movements, such as of the thoracic and lumbar regions, and whether the spinal movement during gait changes after decompression surgery remain unclear. METHODS: Ten patients with lumbar spinal stenosis and 10 healthy controls participated. Clinical outcomes were assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and Visual Analogue Scale. Spinal kinematic data of the participants during gait were acquired using a three-dimensional motion analysis system. The trunk (whole spine), thoracic, and lumbar flexion and pelvic tilting values were calculated. Spinal kinematic data and clinical outcomes were collected preoperatively and 1month postoperatively for the patients. FINDINGS: Compared to that observed preoperatively, the clinical outcomes significantly improved at 1month postoperatively. In the standing position, the preoperative lumbar extension of the patients was significantly smaller than that of the controls. Moreover, during gait, the lumbar flexion relative to the standing position of the patients was smaller than that of the controls preoperatively, and increased at 1month postoperatively. The sum of the thoracic and lumbar flexion values during gait negatively correlated with the score for leg pain. INTERPRETATION: The epidural pressure of lumbar spinal stenosis patients is known to be higher than that of normal subjects during gait, and to decrease during walking with lumbar flexion. Preoperatively, smaller thoracic and lumbar flexion movements during gait relative to the standing position cannot decrease epidural pressure; as a result, severe leg pain might be induced.

Knee biomechanics during walking in recurrent lateral patellar dislocation are normalized by 1 year after medial patellofemoral ligament reconstruction.

PURPOSE: Gait kinematics and kinetics of the knee before and after medial patellofemoral ligament (MPFL) reconstruction in patients with recurrent lateral patellar dislocation (RPD) are unknown. The purpose of this study was to measure knee kinematics and kinetics during gait before and 1 year after anatomical MPFL reconstruction in patients with RPD and compare the results to healthy individuals. METHODS: Eleven RPD patients were treated using an anatomical MPFL reconstruction procedure. Gait analysis was conducted before and at 3, 6, and 12 months after surgery. For comparison, 15 healthy volunteers with no history of orthopaedic problems in their lower limbs were included as the control group. Knee kinematics and kinetics were analysed during gait. RESULTS: Before surgery, the internal knee extension moment in RPD patients was significantly lower than in controls (P = 0.025). At 3 months post-operatively, there was an additional decrease in knee extension moment compared to before surgery, and so it was still significantly lower than in the control group (P < 0.01). One year post-operatively, knee extension moment in the RPD group was significantly increased compared to 3 months post-operatively (P < 0.01). The knee flexion angle in the early stance phase in the RPD group at 3 months post-operatively was significantly lower than that of controls (P < 0.01). Knee kinematics and kinetics were similar to that of controls 1 year after surgery. CONCLUSION: Initially, RPD patients had lower knee extension moments during gait compared with controls, but by 1 year after MPFL reconstruction, knee kinematics and kinetics of gait in the RPD patients had returned to normal. These observations indicate that MPFL reconstruction may help to delay prospective knee OA as long as possible by restoring the conformation of the patellofemoral joint and gait biomechanics by surgery.

Posterior tibial displacement in the PCL-deficient knee is reduced compared to the normal knee during gait.

PURPOSE: Most individuals with an isolated posterior cruciate ligament (PCL) injury do not complain of disability even if posterior instability is objectively revealed by a static physical examination, such as the posterior drawer test. This suggests it is insufficient to only evaluate posterior instability under static conditions. Therefore, we have investigated the effect of isolated PCL injury on the detailed kinematics of the knee in a dynamic environment such as during gait. METHODS: Eight unilateral PCL-deficient males and eight healthy control volunteers participated in this study. Isolated PCL injury was diagnosed by clinical examination. Stress X-ray imaging showed an average side-to-side difference of 12.7 ± 3.5 mm. Knee kinematics including anteroposterior tibial displacement were analysed during walking using the point cluster technique. RESULTS: Posterior tibial displacement from initial contact was significantly smaller during 9-22 % of the gait cycle by an average of 0.4 cm in the PCL group, compared to controls. In the PCL-deficient knee, the external rotational angle increased by an average of 3.3° at the loading response during 3-11 % of the gait cycle and the varus angle from initial contact increased by an average of 2.0° during 28-52 % of the gait cycle, compared to controls. CONCLUSIONS: Dynamic changes in the rotation and posterior translation patterns were seen after isolated PCL injury, suggesting the kinematics of PCL-deficient knees might be different to normal knees. These factors may contribute to long-term osteoarthritic change. Consequently, when choosing conservative treatment for PCL injury, these changes should be considered to prevent osteoarthritic change. LEVEL OF EVIDENCE: III.

[The approach to bone and joint disease for extending the healthy life expectancy].

In Japan, the super-aged society, the difference between the healthy life expectancy and life expectancy is large, it has become a social problem. For the extension of healthy life expectancy, measures to bone and joint disease are important. Lower limb muscle strengthening is useful to decrease in pain and improvement of walking ability. Further, in order to maintain a balance function, improvement in range of motion is important. On the other hand, for patients who had joint destruction, decreased ability of exercise, muscle weakness, balance dysfunction has already occurred, it is necessary for extension of healthy life expectancy including surgical treatment. We believe that by performing the appropriate therapeutic intervention, extending healthy life expectancy would be possible.