The Effects of Chronic Pain Levels on Lower Extremity Energetics During Jump Landing/Cutting in Chronic Ankle Instability Patients

Up to 75% of patients with lateral ankle sprains develop chronic ankle instability (CAI). A majority of CAI patients report chronic pain and show altered jump landing/cutting patterns. Calculating joint energetics affected by chronic pain provides insight into understanding the effects of chronic pain levels on lower limbs in CAI patients. PURPOSE: To identify the effects of chronic pain levels on lower limb energetics during jump landing/cutting in CAI patients. METHODS: This study was a cross-sectional study. Fifteen CAI patients with high pain (High pain) (6males, 9females; age=22.1±2.1year; height=1.74±0.09m; mass=71.3±10.6kg, pain=66.9±9.4), matched 15 CAI patients with low pain (Low pain) (6males, 9females; age=22.3±2.1year; height=1.74±0.08m; mass=70.1±10.7kg, pain=89.3±2.6), and matched 15 healthy controls (Control) (6males, 9females; age=21.3±1.7year; height=1.73±0.08m; mass=70±10.3kg, pain=100±0). We followed the International Ankle Consortium and utilized the Foot and Ankle Outcome Scores for CAI and chronic pain levels. Ground reaction forces were collected during the jump landing/cutting, while joint power was defined by angular velocity and joint moment data. We calculated ankle, knee, and hip joint energy via the integration of negative (dissipation) or positive (generation) power curve areas. The loading phase was defined by the time from initial contact to 150 ms following, while the cutting phase extended from maximal knee flexion to 150 ms following. The Wilcoxon signed-rank test was used to assess joint energetics data. RESULTS: The high pain showed less energy dissipation and generation in the ankle during the loading and cutting phase than the low pain (p=.013 and p=.002) and control (p=.018 and p=.028). The high pain exhibited more energy generation in the hip during the cutting phase than the low pain (p=.038) and control (p=.013). CONCLUSION: The high pain showed lower energy dissipation and generation in the ankle during the loading and cutting phase than the low pain and control, possibly reflecting an effort to reduce the burden on the ankle joint. The high pain reported more energy generation in the hip during the cutting phase than the low pain and control, suggesting a proximal compensatory strategy. Therefore, chronic pain may impact motor outcomes

Examining the Acute Effects of Virtual Reality on the Star Excursion Balance Test in Chronic Ankle Instability

Chronic ankle instability (CAI) patients display mechanical and functional restrictions, along with neurocognitive dysfunction after lateral ankle sprains. Athletes need to divide their attention to effectively multitask during sports activities. Recent studies have utilized virtual reality (VR) to simulate dynamic sporting environments, aiming to enhance cognitive and postural control. However, little is known about the acute effects of VR on dynamic postural control in CAI patients. PURPOSE: To identify the acute effects of VR gear on dynamic postural control in CAI patients. METHODS: This study was a cross-over study. Twenty CAI patients (11males, 9females; age=21±3year; height=1.63±0.28m; mass=74±13.1kg). We used the Foot and Ankle Ability Measures and Ankle Instability Instrument questionnaires for CAI. VR training included 3 trials of single-leg stance; double and single-leg drop landings; and 5 trials of jump landing/cutting. Before and after VR training, participants performed 3 trials each in 3 directions: anterior (ANT), posteromedial (PM), and posterolateral (PL). The average reach distance was normalized by an individual’s leg length from the anterior superior iliac spine to the distal end of the medial malleolus. Matched paired t-tests were used to evaluate the acute effect (posttest-pretest difference) of VR training. The significance level for all analyses was set at a priori of p≤0.05. RESULTS: Acute effects were not observed in both ANT and PM directions (60.2±7.2 vs. 60.9±6.9, p=0.15 and 103.3±10.4 vs. 104.6±11.2, p=0.31). CAI patients showed an acute effect, improving PL reach distance (98.3±11.2 vs. 102.1±13.3, p=0.006) during the star excursion balance test after VR training. CONCLUSION: VR resulted in no difference in ANT direction, which is related to the dorsiflexion range of motion, suggesting that VR training had no improvement in mechanical restriction. After VR training, PL reach distance was increased, suggesting improvement in functional restriction in CAI patients. Therefore, VR training may affect functional restriction, by potentially increasing eversion strength and improving mediolateral static postural control. More data are needed to determine if VR may reduce the risk of recurrent ankle sprains in CAI patients

Effects of Anticipation on Energy Dissipation Patterns among Chronic Ankle Instability Patients

Ankle inversion injuries often lead to chronic ankle instability (CAI). CAI patients use altered energy dissipation patterns during jump-landing, but most studies have been limited to tasks performed under anticipated conditions. It is unclear how the anticipatory condition affects joint energetics in CAI patients. PURPOSE: To identify the effects of anticipation on energy dissipation during jump-landing among CAI, coper, and control subjects. METHODS: 60 subjects were categorized according to the Foot and Ankle Ability Measure and Ankle Instability Index. 20 CAI patients (10males, 10females, 1.74±0.1m, 69.1±10.2kg), 20 Copers (10males, 10females, 1.76±0.1m, 70.9±11.1kg), and 20 Controls (10males, 10females, 1.74±0.1m, 66.0±10.7kg) participated. Participants completed 3 trials of maximal jump-landing tasks (via arrows shown on a screen) performed under anticipated/unanticipated conditions. Energy dissipation by the ankle, knee, and hip joints was calculated by integrating regions of the joint power curve during the task. Lower extremity joint energy dissipation was calculated for the hip, knee, and ankle in the sagittal plane during 50, 100, 150, and 200 ms after initial contact with the force plate. Two-way repeated measures ANOVAs (group × condition) were used to examine the differences between condition (Anticipated, Unanticipated) and group (CAI, coper, control). RESULTS: In the unanticipated condition, copers displayed reduced ankle/hip energy dissipation and increased knee energy dissipation compared to the anticipated condition, while the CAI and Control groups demonstrated no change in energy dissipation between the two conditions. CONCLUSION: CAI patients were unable to change energy dissipation patterns between the two conditions. This finding may represent an apprehension for extra ankle strain compared to the copers. In the earliest stages of jump-landing, copers displayed the most altered energy dissipation patterns, shifting from heavily favoring the ankle during anticipated movement to dissipating much more energy into the knee while reducing the load on the ankle. These energy patterns may indicate a coping mechanism and increased knee energy dissipation in copers may be an effort to attenuate load during landing as a strategy to lessen the load absorbed by the ankle

The Effects of Chronic Pain Levels on Lower Extremity Muscle Activation During Jump Landing/Cutting in Individuals with Chronic Ankle Instability

Lateral ankle sprains (LASs) are the most common injury in sports. Up to 74% of individuals with an initial LAS develop chronic ankle instability (CAI) with chronic ankle pain being one of the residual symptoms. PURPOSE: To Identify the effects of chronic pain levels on lower extremity muscle activation during a maximal jump landing/cutting in CAI individuals. METHODS: This study was a cross-sectional study. Twenty CAI individuals with high pain (High pain) (9M, 11F; age=22±2year; height= 1.74±0.10m; mass=79.4±14.6kg, pain=67.4±7.7), 20 CAI individuals with low pain (Low pain) (9M, 11F; age=21±3year; height=1.73±0.08m; mass=74.2±12.7kg, pain=91.7±3.9), and 20 healthy controls (Control) (9M, 11F; age=22±1year; height=1.74±0.09m; mass=68.2±10.2kg, pain=100±0). We followed the International Ankle Consortium and Foot and Ankle Outcome Scores for classification of CAI and chronic pain. Electromyography (EMG) data were collected using wireless surface electrodes (2,000 Hz) during 5 trials of maximal jump landing/cutting from initial contact to toe-off (0-100% of stance). Reference EMG data were collected standing position for 3 seconds. EMG data were normalized to the reference EMG data. The electrodes were placed over the tibialis anterior (TA), peroneus longus (PL), medial gastrocnemius (MG), vastus lateralis (VL), gluteus medius (Gmed), and gluteus maximus (Gmax). Functional analyses of variance were used to evaluate between-group differences for kinematics outcomes. RESULTS: The high pain showed 3.3%, 16%, and 14% less activation in TA, PL, and MG, and 16% and 14% more activation in the VL and Gmed than the low pain. The high pain displayed 26%, 11.1%, 15%, 8.2%, 25.4%, and 11.5% less activation in the TA, PL, MG, VL, Gmed, and Gmax than the control. The low pain showed 14.9%, 18.7%, and 11.2% less activation in the TA, VL, and Gmed, and 8.7% more activation in the PL during the landing/cutting than the control. CONCLUSION: Chronic pain levels appear to impact muscle activation in CAI individuals. Both the high and low pain demonstrate altered muscle activation patterns in distal and proximal joints. The high pain prompts a hip-dominant strategy, compensating for deactivated distal muscles. The lower the level of chronic pain, the more active the PL muscles that contribute to ankle stability

The Effects of Chronic Pain Levels on Joint Angle During Jump Landing/Cutting in Individuals with Chronic Ankle Instability

About 60% of chronic ankle instability (CAI) individuals report ankle pain persisting for longer than 3 months. They have the risk of recurrent ankle sprains while performing multiplanar tasks such as jumping with landing/cutting. However, little is known about the effects of chronic pain levels on joint kinematics differences and how chronic pain levels contribute to motor outcomes when performing multiplanar motions. PURPOSE: To identify the effects of pain levels on kinematics during jump landing/cutting in CAI individuals. METHODS: This study was a cross-sectional study. Twenty CAI patients with high pain (high pain) (9 males, 11 females; age=22±2year; height=1.74±0.10m; mass=79.4±14.6kg, pain=67.4±7.7), 20 CAI patients with low pain (low pain) (9 males, 11 females; age=21±3year; height=1.73±0.08m; mass=74.2±12.7kg, pain=91.7±3.9), and 20 healthy controls (9 males, 11 females; age=22±1year; height=1.74±0.09m; mass=68.2±10.2kg, pain=100±0). We followed the International Ankle Consortium criteria for classifying CAI and utilized the Foot and Ankle Outcome Scores for chronic pain levels. We used 44 reflective markers to calculate joint angles collected during the jump landing/cutting task from initial contact to toe-off (0-100% of stance). Functional analyses of variance were used to evaluate between-group differences for kinematics outcomes. RESULTS: The high pain showed 4.8° less plantarflexion from 0-12% than the low pain from 0-8% and 4.9° less plantarflexion than the healthy control. The high pain exhibited 1.4° less inversion from 8-12% than the low pain. The knee joint presented 1.5° less flexion from 0-5% and then 4.4° more flexion at 10-24% than healthy controls, showing a greater knee joint angle variability. The high pain showed 5.3°, 3.6°, and 3.5° higher hip flexion from 2-24%, 50-61%, and 75-82%, respectively than the healthy control. CONCLUSION: The high pain demonstrated less plantarflexion and inversion in the ankle while exhibiting more kinematics variance in the knee joint and hip during multiplanar tasks. These findings may result in a stiffer landing in the ankle and proximal landing strategy during jump landing/cutting tasks. Thus, chronic pain levels affect joint kinematics during multiplanar tasks

Femoral Articular Cartilage Quality, but Not Thickness, Is Decreased for Anterior Cruciate Ligament Reconstruction Patients Relative to Control

Anterior cruciate ligament reconstruction (ACLR) patients are at risk of developing posttraumatic knee osteoarthritis (OA). The etiology of posttraumatic knee OA is complex, potentially involving biomechanical and biochemical factors. Changes in femoral cartilage thickness and composition are associated with knee OA, while current research is ambiguous on cartilage in ACLR patients. PURPOSE: This study aimed to compare femoral cartilage thickness and T2 relaxation time (a compositional measure) between ACLR patients and healthy controls in a resting state. We hypothesized that ACLR patients would exhibit thinner femoral cartilage and increased T2 relaxation times. METHODS: Twenty ACLR patients (6-24 months post-surgery) and 20 matched healthy controls were recruited following institutional board approval. Ultrasound and magnetic resonance imaging data were collected on two separate days, allowing cartilage thickness and composition measurements to be made, respectively. Statistical analyses, including independent t-tests and Holm-Bonferroni corrections, were performed on selected regions of interest. RESULTS: The ACLR group showed increased T2 relaxation times in four of eight femoral regions compared to controls. No significant differences in femoral cartilage thickness were observed between the groups. The primary finding from this study is that ACLR patients did not show differences in femoral cartilage thickness (a morphological measure), but displayed prolonged T2 relaxation times (a compositional measure) compared to controls, at rest. This finding suggests that compositional changes precede morphological shifts in femoral cartilage in early post-ACLR periods (6-24 months). CONCLUSION: These early compositional changes may indicate articular cartilage that is more compressible and subject to increased strain on the solid components of the joint. While ultrasound is a more accessible imaging method, magnetic resonance imaging may provide a more accurate and early evaluation of cartilage quality. Further research is needed to develop practical tools for early detection and monitoring of cartilage degradation in ACLR patients before progression into knee osteoarthritis

Effects of Running on Femoral Articular Cartilage Thickness for Anterior Cruciate Ligament Reconstruction Patients and Non-ACLR Control Subjects

Anterior cruciate ligament reconstruction (ACLR) patients are more likely to develop posttraumatic knee osteoarthritis than non-ACLR counterparts. The effect of running on femoral articular cartilage thickness is unclear. PURPOSE: The purpose of this study was to compare how 30 minutes of running influences femoral articular cartilage thickness for ACLR patients and non-ACLR control subjects. We hypothesized that running would deform the femoral articular cartilage more for the ACLR patients than for the control subjects. METHODS: We recruited 20 individuals with primary unilateral ACLR and 20 matched non-ACLR controls. ACLR patients and control subjects were matched based upon age, gender, BMI, and weekly running mileage. The present procedures were approved by the appropriate institutional board and all subjects provided informed consent before data collection. We used ultrasound imaging to measure femoral articular cartilage thickness before and after 30 minutes of running. The ultrasound images were manually analyzed using ImageJ software by the same investigator. Total femoral articular cartilage cross-sectional area of each image was segmented into three regions: medial, lateral, and intercondylar. Deformation due to the run was compared between the ACLR patients and control subjects for each region using independent t tests (P \u3c 0.05, adjusted for multiple comparisons). RESULTS: The 30-minute run resulted in more deformation for the ACLR patients (0.03 ± 0.01 cm) than the matched controls (0.01 ± 0.01 cm) for the medial region (p \u3c 0.01) of the femoral articular cartilage. Identically, the 30-minute run resulted in more deformation for the ACLR patients (0.03 ± 0.01 cm) than the matched controls (0.01 ± 0.01 cm; p \u3c 0.01) for an average of the entire articular cartilage area (medial, lateral, and intercondylar). No significant differences existed between groups for the lateral or intercondylar regions. CONCLUSION: Thirty minutes of running deformed medial and overall femoral articular cartilage more for ACLR patients than non-ACLR control subjects

Running Biomechanics and Knee Cartilage Health in ACLR Patients

Anterior cruciate ligament reconstruction (ACLR) patients are more likely to subsequently suffer from knee osteoarthritis than non-ACLR counterparts. Exercise is thought to influence articular cartilage, however, it is unclear how running biomechanics are associated with femoral cartilage thickness and composition in ACLR patients. PURPOSE: The purpose of this study was to investigate relationships between running biomechanics and measures of femoral articular cartilage condition (thickness and composition) in ACLR patients and control subjects. METHODS: We used ultrasound and MRI (T2 mapping sequence) to measure articular cartilage thickness and composition, respectively, for 20 ACLR patients (age: 23 ± 3 yrs; mass: 70 ± 10 kg; time post-ACLR: 14.6 ± 6.1 months) and 20 matched controls (age: 22 ± 2 yrs; mass: 67 ± 11 kg). After these measures, all participants completed a 30-minute run on a force-instrumented treadmill. Correlational analyses were used to explore relationships between running biomechanics (vertical ground reaction force (vGRF)) and femoral cartilage thickness and composition (T2 relaxation time). The present procedures were approved by the appropriate institutional board and all subjects provided informed consent before data collection was performed. RESULTS: Significant positive correlations existed for the control subjects only between peak vGRF and overall (r = 0.34; p \u3c 0.01), medial (r = 0.23; p \u3c 0.01), lateral (r = 0.39; p = 0.02), and intercondylar (r = 0.31; p \u3c 0.01) femoral thickness. The ACLR patients showed significant negative correlations between T2 relaxation time for the central-medial region of the femoral condyle, and peak vGRF (r = −0.53; p = 0.01) and vertical impulse due to the vGRF (r = −0.46; p = 0.04). CONCLUSION: These findings offer some limited support for the idea that femoral articular cartilage benefits from increase vGRF during running. This is evidenced by the increased thickness for the control subjects and decreased T2 relaxation time (indicative of increased free-flowing water in the cartilage) for the ACLR patients, as running vGRF increased

Job satisfaction and moral distress of nurses working as physician assistants: focusing on moderating role of moral distress in effects of professional identity and work environment on job satisfaction

Abstract Background Physician assistant was created in response to a shortage of physicians. However, this profession is not officially recognized in Korea. Many nurses are working as physician assistants. Their job satisfaction was low due to role conflict. Job satisfaction plays a major role in providing high quality nursing. This study aimed to investigate effects of work environment and professional identity on job satisfaction and identify the mediating role of moral distress in such effects. Methods Participants were 112 nurses working as physician assistants. They were recruited from three General Hospitals. A questionnaire scale was used to collect data. Data were analyzed using frequency, descriptive statistics, independent t-test, one-way ANOVA, Pearson correlation, and Macro Model 4 with SPSS Statistics. Results Job satisfaction of nurses working as physician assistants had a score of 3.08 out of 5. It showed significant associations with work environment and professional identity. Moral distress had a partial mediating role in relationships of job satisfaction with work environment and professional identity. Conclusion Many nurses are working as physician assistants, although physician assistant as a profession is not officially recognized in Korea. Nurses working as physician assistants experience confusion about their professional identity and moral distress. For better nursing outcomes, physician assistant policy should be improved, and various strategies should be provided to improve their job satisfaction