Comparison of Differences in Thigh Muscle Morphology and Function according to Post-anterior Cruciate Ligament Surgery Period

PURPOSE Quadriceps muscle weakness caused by muscle atrophy is a typical feature of individuals who undergo anterior cruciate ligament reconstruction. Although many studies have suggested an acceptable timing for returning to sports after anterior cruciate ligament reconstruction, there are still many controversies. Therefore, this study aimed to present an evidence-based recommendation for returning to sports after anterior cruciate ligament reconstruction by evaluating muscle size and function 9 months after the reconstruction. METHODS Eighteen patients who underwent anterior cruciate ligament reconstruction were evaluated for quadricep thickness and isokinetic knee extension strength in both limbs. The Mann-Whitney U test was used to compare the differences 1) in thigh muscle thickness and isokinetic knee extension strength between the reconstructed limbs in “more than 9 months after surgery” and “less than 9 months after surgery” groups and 2) between the limb symmetry index of the two groups. RESULTS The main findings were that the vastus medialis thickness and isokinetic knee extension strength for the reconstructed limbs were significantly greater in the more than 9 months after surgery group (vastus medialis: Z=12.00, p=.014; strength: Z=16.00, p= .034). The vastus medialis and vastus intermedius thicknesses in the more than 9 months after surgery group also showed a significant increase compared to those in the less than 9 months after surgery group (vastus medialis: Z=10.00, p=.006; vastus intermedius: Z= 10.00, p=.006). CONCLUSIONS After anterior cruciate ligament reconstruction, selective muscle atrophy and weakness in the quadriceps muscles were observed. This study emphasizes the need for targeted early rehabilitation of specific quadriceps muscles to prevent muscle atrophy and weakness after anterior cruciate ligament reconstruction

The influence of exercise on single leg jump-cut and double leg jump landing biomechanics

An important field of study within the exercise science realm lies in identifying risk factors for musculoskeletal injuries to inform injury prevention programs. One of the more serious injuries in sports, especially sports involving cutting and jumping, is sprain of the anterior cruciate ligament (ACL). Previous research has found that women are at greater risk for ACL injuries and this injury most commonly occurs during a deceleration movement. For this study, we measured landing biomechanics before and after an exercise protocol to gain insight on the influence of fatigue on knee position and loading during a single leg jump-cut and a double leg jump landing. Forty female participants between the ages of 18-30 who were free of musculoskeletal injury, had no history of ACL injury, and engaged in at least 150 minutes of moderate exercise per week were enrolled. Subjects performed two landing tasks: 1) a double leg landing from a 30 cm high box placed a distance of 50% of their height from the edge of two force platforms and 2) a single leg jump-cut over a small hurdle from a distance of 50% of their max height behind the force platforms prior to completing an exercise protocol. For the exercise protocol, subjects performed 6 cycles of treadmill walking at a self-selected speed between 3.0-3.5 mph for 5 minutes followed by one minute of jumping activities. Following the 30-minute exercise protocol, landing biomechanics were again measured as the subjects repeated the two landing tasks. The results presented in this poster will compare changes in single leg jump-cut and double leg jump landing biomechanics due to exercise. The specific variables of interest are: knee flexion angle at initial contact, peak internal knee extension and varus moments, knee valgus angle at initial contact, and peak knee valgus angle. These factors have previously been identified as significant predictors of ACL injury. By comparing the effects of exercise on knee biomechanics throughout both the single leg jump-cut and the double leg jump landing tasks we aim to identify if the biomechanical changes that occur from exercise are similar between tasks or if they are task dependent.This project was presented at Oregon State University's Celebrating Undergraduate Excellence 2015

Effects of physical activity participation on cognitive impairment in older adults population with disabilities

BackgroundExisting research on the association between cognitive function and physical activity in the older adults population with disabilities is limited. Additionally, there is a need to explore avenues for enhancing the longevity and quality of life among these individuals.ObjectiveThis study aimed to investigate the independent and joint associations between cognitive function and levels of physical activity in the older adults population with disabilities.MethodsA total of 315 older adults adults (men = 182, women = 133), identified with disabilities based on medical evaluation, were recruited from the first survey of the Korean Longitudinal Study of Aging (KLoSA). Participants underwent assessments for cognitive function, physical activity (PA), activities of daily living (ADLs), instrumental activities of daily living (IADLs), and grip strength.ResultsADLs (p < 0.001) and IADLs (p < 0.001) scores were significantly higher in the male normal cognitive group compared to both the male and female cognitive impairment groups. In an unadjusted model, disabled older adults individuals who did not meet the recommended PA guidelines showed an increased odds ratio for cognitive dysfunction (OR = 2.29, 95% CI = 1.32–3.97). Those participating in PA at least 1 day per week also demonstrated an elevated odds ratio (OR = 1.22, 95% CI = 1.08–1.38) for cognitive dysfunction compared to those who engaged in regular PA. A negative correlation was observed between K-MMSE scores and grip strength (r = 0.448, p < 0.001).ConclusionThis study provides robust evidence that disabled older adults individuals who do not meet the recommended guidelines for PA or who do not participate in PA at least once a week have an increased likelihood of cognitive impairment compared to those who are regularly active

Influence of prophylactic ankle tapes on lower-extremity kinematics during a stop-jump task in chronic ankle instability

Background and objective: Numerous tape applications have been used in patients with chronic ankle instability (CAI). However, the effect of prophylactic ankle taping on lower-extremity kinematics is still not well understood. This study aimed to investigate the effects of traditional taping, fibular repositioning taping, and kinesiology taping on the peak angles of the lower extremities in patients with CAI. Materials and Methods: A total of 14 men (age, 24.07 ± 4.46 years; height, 175.06 ± 5.10 cm; weight, 82.24 ± 10.38 kg (mean ± standard deviation)) with CAI identified using screening questionnaires (Cumberland Ankle Instability Tool, 17.64 ± 4.14; Foot and Ankle Ability Measure (FAAM) Activity of Daily Living, 86.69 ± 6.71; and FAAM Sports Subscale, 75.45 ± 6.70) participated. The peak angles of the hip, knee, and ankle joints during a stop-jump task, with and without tape application, were collected using a three-dimensional motion system. Results: The following peak angles were measured: hip flexion, hip adduction (ADD), hip internal rotation (IR), knee flexion, knee abduction (ABD), knee IR, ankle dorsiflexion, ankle inversion, and ankle ADD. No significant differences were observed in the peak angle of each joint across conditions (hip flexion, F(3,39) = 0.85, p = 0.47; hip ADD, F(1.729,22.478) = 1.90, p = 0.18; hip IR, F(1.632,21.220) = 0.67, p = 0.49; knee flexion, F(3,39) = 1.24, p = 0.15; knee ABD, F(1.691,21.982) = 1.24, p = 0.30; knee IR, F(1.830,23.794) = 0.44, p = 0.63; ankle dorsiflexion, F(3,39) = 0.66, p = 0.58; ankle inversion, F(1.385,18.007) = 0.85, p = 0.40; ankle ADD, F(1.865,24.249) = 2.23, p = 0.13). Conclusion: The application of different taping techniques did not significantly change the peak joint angles of the lower extremities during a stop-jump task. These results contradict those of previous studies, suggesting that ankle taping restricts joint range of motion

Anterior Cruciate Ligament Reconstructed Patients Who Recovered Normal Postural Control Have Dissimilar Brain Activation Patterns Compared to Healthy Controls

Postural control, which is a fundamental functional skill, reflects integration and coordination of sensory information. Damaged anterior cruciate ligament (ACL) may alter neural activation patterns in the brain, despite patients’ surgical reconstruction (ACLR). However, it is unknown whether ACLR patients with normal postural control have persistent neural adaptation in the brain. Therefore, we explored theta (4–8 Hz) and alpha-2 (10–12 Hz) oscillation bands at the prefrontal, premotor/supplementary motor, primary motor, somatosensory, and primary visual cortices, in which electrocortical activation is highly associated with goal-directed decision-making, preparation of movement, motor output, sensory input, and visual processing, respectively, during first 3 s of a single-leg stance at two different task complexities (stable/unstable) between ACLR patients and healthy controls. We observed that ACLR patients showed similar postural control ability to healthy controls, but dissimilar neural activation patterns in the brain. To conclude, we demonstrated that ACLR patients may rely on more neural sources on movement preparation in conjunction with sensory feedback during the early single-leg stance period relative to healthy controls to maintain postural control. This may be a compensatory protective mechanism to accommodate for the altered sensory inputs from the reconstructed knee and task complexity. Our study elucidates the strategically different brain activity utilized by ACLR patients to sustain postural control

Bilateral Comparisons of Quadriceps Thickness after Anterior Cruciate Ligament Reconstruction

Background and objectives: Anterior cruciate ligament reconstruction (ACLR) often results in quadricep atrophy. The purpose of this study was to compare the bilateral thickness of each quadricep component before and after ACLR. Materials and Methods: Cross-sectional study design. In 14 patients who underwent ACLR, bilateral quadricep muscle thicknesses were measured using a portable ultrasound device, 1 h before and 48–72 h after ACLR. Two-way analysis of variance (ANOVA) was used to compare muscle thickness pre- and post-ACLR between the limbs. Results: The primary finding was that the vastus intermedius (VI) muscle was significantly smaller in the reconstructed limb after ACLR compared to that in the healthy limb (Reconstructed limb; RCL = Pre-operated (PRE): 19.89 ± 6.91 mm, Post-operated(POST): 16.04 ± 6.13 mm, Healthy limb; HL = PRE: 22.88 ± 6.07, POST: 20.90 ± 5.78 mm, F = 9.325, p = 0.009, η2p = 0.418). Conclusions: The results represent a selective surgical influence on the quadricep muscle thickness. These findings highlight the need of advanced strengthening exercises in order to restore VI thickness after ACLR

Explosive Quadriceps Strength and Landing Mechanics in Females with and without Anterior Cruciate Ligament Reconstruction

Lower explosive quadriceps strength, quantified as rate of torque development (RTD), may contribute to landing mechanics associated with anterior cruciate ligament (ACL) injury risk. However, the association between quadriceps RTD and landing mechanics during high demand tasks remains unclear. Therefore, this study investigated the influence of quadriceps RTD on sagittal plane landing mechanics during double-leg jump landings (DLJL) and single-leg jump cuts (SLJC) in females with and without ACL reconstruction (ACLR). Quadriceps RTD was measured during isometric muscle contractions. Landing mechanics were collected during DLJL and SLJC tasks. Separate stepwise multiple linear regression models determined the amount of variance in sagittal plane landing mechanics that could be explained by quadriceps RTD, group (ACLR or Control), and their interaction. The results indicate that greater quadriceps RTD is associated with lower loading rate (p = 0.02) and longer time to peak vertical ground reaction force (p = 0.001) during SLJC, regardless of ACLR status. As greater loading rate may lead to higher risk of ACL injuries and post-traumatic knee osteoarthritis post-ACLR, explosive muscle strength interventions might be useful for individuals with and without ACLR to facilitate the use of safer landing mechanics

Conduction Velocity of Spinal Reflex in Patients with Acute Lateral Ankle Sprain

Recent literature has highlighted altered spinal-reflex excitability following acute lateral ankle sprain (ALAS), yet there is little information on the conduction velocity of spinal reflex pathways (CV-SRP) in these patients. Therefore, we aimed to investigate the effects of ALAS on the CV-SRP. We employed a cross-sectional study with two groups: ALAS (n = 30) and healthy controls (n = 30). The CV-SRP of the soleus, fibularis longus, and tibialis anterior was assessed using the H-index method. As secondary outcomes, H-reflex and M-wave latencies were assessed as well as acute symptoms including ankle swelling, pain, and self-reported ankle function. Separate group-by-limb ANOVA with repeated measures revealed a significant interaction for soleus CV-SRP (p < 0.001) and H-reflex latency (p < 0.001), showing significant slower CV-SRP and longer H-reflex latency in the involved limb of the ALAS group compared with both limbs in the control group. However, there was no significant interaction or main effect in any other ankle muscles (p > 0.05). A further correlation analysis showed a significant relationship between CV-SRP and acute symptoms, including ankle swelling (r = −0.37, p = 0.048) and self-reported ankle function (r = 0.44, p = 0.017) in ALAS patients. These results suggest a disrupted functionality of the afferent pathway and/or synaptic transmission following ALAS. Level of Evidence: 4