Environmental Risk Factors for Osteoarthritis: The Impact on Individuals with Knee Joint Injury.

Osteoarthritis is a debilitating chronic condition involving joint degeneration, impacting over 300 million people worldwide. This places a high social and economic burden on society. The knee is the most common joint impacted by osteoarthritis. A common cause of osteoarthritis is traumatic joint injury, specifically injury to the anterior cruciate ligament. The purpose of this review is to detail the non-modifiable and modifiable risk factors for osteoarthritis with particular focus on individuals after anterior cruciate ligament injury. After reading this, health care providers will better comprehend the wide variety of factors linked to osteoarthritis.

Modified Biering-Sorenson Protocol Changes Joint Contributions to Total Support in Individuals with a History of Anterior Cruciate Ligament Reconstruction During Drop Vertical Jump Landings.

BACKGROUND: There are persistent deficits of the proximal musculature in individuals with anterior cruciate ligament reconstruction. Previous research has shown that proximal musculature fatigue alters drop vertical jump performance in healthy individuals. It is unknown how proximal musculature fatigue will alter drop vertical jump performance in individuals who have undergone anterior cruciate ligament reconstruction. HYPOTHESIS/PURPOSE: The purpose of this study was to examine the effects of a proximal extensor musculature fatigue protocol on drop vertical jump landing biomechanics of individuals with a history of anterior cruciate ligament reconstruction using both single-joint parameters and total support moment analysis. STUDY DESIGN: Quasi-experimental pre-post laboratory experiment. METHODS: Nineteen participants with a history of unilateral anterior cruciate ligament reconstruction were recruited. Three-dimensional motion analysis was performed bilaterally during a drop vertical jump. Participants then completed a proximal extensor musculature fatigue protocol and immediately repeated the drop vertical jump task. Sagittal plane kinetics and kinematics were collected. Joint contributions to peak total support moment were calculated. A condition-by-limb repeated measures analysis of variance was performed to explore the effects of the fatigue protocol, using an alpha level of 0.05. RESULTS: There were no interactions observed for any parameters. However, the injured limb demonstrated less vertical ground reaction force (13%, p=0.013) and reduced peak dorsiflexion angle (2°, p=0.028) both before and after the protocol. After the fatigue protocol both limbs demonstrated reduced hip extensor contribution to peak total support moment (4%, p=0.035). CONCLUSIONS: Individuals with a history of anterior cruciate ligament reconstruction performed the drop vertical jump with an altered anti-gravity support strategy after the proximal extensor musculature fatigue protocol. The significant reduction in bilateral hip extensor contribution to peak total support moment suggests evidence of targeted fatigue. LEVEL OF EVIDENCE: III.

Three-dimensional joint kinematic and two-dimensional quality of movement comparison between lateral and forward step-downs.

OBJECTIVES: While lateral and forward step-down tasks are commonly used, they may have different kinematic and performance demands that could influence clinical assessment and rehabilitation. Therefore, the purpose of this study was to compare 3D lower extremity kinematics and 2D quality of movement between the tasks. DESIGN: Cross-sectional comparative study. SETTING: Research laboratory. PARTICIPANTS: Thirty healthy adults (18 females, age = 23.2 ± 1.4 years, BMI = 23.9 ± 2.2 kg/m2). MAIN OUTCOME MEASURES: Participants underwent 3D and 2D motion analysis. 3D variables were peak hip, knee, and ankle angles. Dichotomous clinical criteria were used for 2D assessment. An alpha level of 0.05 was used for statistical analyses. RESULTS: In the sagittal plane, the forward step-down averaged 7° more knee flexion (p < 0.001, d = 2.30) and 4° more ankle dorsiflexion (p < 0.001, d = 1.72), but 2° less hip flexion (p = 0.001, d = 0.64). In the frontal plane, forward step-downs averaged 1° more hip adduction (p = 0.006, d = 0.54) and 1° more ankle eversion (p < 0.001, d = 1.04). The forward step-down elicited 2D movement faults more often (p = 0.003). CONCLUSIONS: The increased knee flexion and ankle dorsiflexion demands of the forward step-down were accompanied by increases in frontal plane aberrations. The forward step-down may be more challenging for individuals with reduced tolerance to loaded knee flexion and/or limited ankle mobility.

Relationship of clinical measures with humeral torsion in young adults: a pilot study.

PURPOSE: Humeral retroversion alters range of motion and has been linked to injury risk. Clinically,palpation of the bicipital groove is used to quantify humeral torsion, but the accuracy of this procedure has not been fully examined. The purpose of this study was to investigate the relationship between clinical and diagnostic ultrasound (US) assessment of humeral torsion while considering shoulder position of the participant and clinical expertise of the examiner. METHODS: Seventeen participants (34 shoulders, 16/17 right handed, 10/17 history of throwing) were recruited. US was assessed by an experienced assessor. Two clinical assessments of humeral torsion were performed by two assessors of different experience (expert and novice). Humeral torsion was assessed at 90 degrees shoulder abduction (Palp90) and 45 degrees shoulder abduction (Palp45). Within assessor intraclass correlation coefficients (ICC (3, 1) were calculated. Correlation coefficients (Pearson's) were generated to determine relationship between clinical and US examination findings. RESULTS: Intra-rater reliability for clinical tests were good (ICCs .73 - .92) for both raters. Of the palpation tests, only the expert assessor was significantly correlated to the US measurement (p<.001) at Palp45 (r = .64) and Palp90 (r = .62). For the expert, there was a significantly lower angle calculated for Palp45 compared to Palp90 (p<.001). CONCLUSION: The accuracy of both palpation methods for assessing humeral retrotorsion may depend on the training background of the assessor. Further, the glenohumeral position of the patient during palpation should be consistent for the purposes of repeated testing.

Trunk Muscle Endurance in Individuals With and Without a History of Anterior Cruciate Ligament Reconstruction.

ABSTRACT: Werner, DM and Barrios, JA. Trunk muscle endurance in individuals with and without a history of anterior cruciate ligament reconstruction. J Strength Cond Res 35(1): 118-123, 2021-Anterior cruciate ligament (ACL) rupture is one of the most common knee injuries and often leads to surgery. Second injury after an ACL reconstruction (ACLR) is a major risk after rehabilitation, and may be linked to persistent postoperative deficits in muscular strength and endurance. Trunk muscle endurance has not been well studied after ACLR. Therefore, the purpose of this study was to compare trunk endurance using the established McGill testing battery in 20 individuals who had previously undergone ACLR at least 1 year before with 20 controls matched for sex frequency, limb dominance, age, body mass index, and activity level. Four static positional holds to failure were performed in random order, with time in seconds recorded as the primary dependent variable. Mann-Whitney U tests using an alpha level of 0.05 were conducted comparing hold times for all positions between groups. Effect sizes were also calculated between groups. Deficits in trunk extension endurance were observed in the surgical group. The results of this study suggest that contemporary rehabilitation schemes after ACLR do not fully address trunk endurance deficits. Health care professionals delivering postoperative rehabilitation after ACLR may consider direct assessment of trunk endurance and targeted exercise training to address potential deficits.

In-Line Half-Kneeling as a Motor Control Test of Core Stability: Known-Groups Validity and Reliability.

Context: Core stability is considered critical for the successful execution of rehabilitative and athletic tasks. Although no consensus definition exists, different components related to core stability have been identified. An important component is the domain of motor control. There are few clinical tests assessing the motor control component of core stability (MCCS). Objective: To evaluate the interrater reliability and known-groups validity of a novel test of MCCS, the in-line half-kneeling test. The test is aimed at assessing MCCS by challenging the ability to maintain a static position with minimized contributions from the distal extremities over a minimized base of support. Design: Cross-sectional group comparison study. Setting: Laboratory. Patients or Other Participants: A total of 75 participants (25 individuals with a history of anterior cruciate ligament reconstruction, 25 uninjured Division 1 collegiate athletes, and 25 uninjured controls) were recruited from a university community. Intervention: Participants were video recorded while performing the in-line half-kneeling test for 120 seconds bilaterally. Three observers independently viewed each video to determine if individuals broke form during each test using 2 dichotomous criteria. Main Outcome Measures: Cohen's kappa was used to assess interrater reliability, and chi-square tests of independence were used to compare break rates between groups. Results: Good-to-excellent interrater reliability (.732-.973) was seen between the 3 observers. Chi-square tests of independence revealed different break rates between all 3 groups. Compared to break rate for the reference control group (11/25-44%), those with a history of anterior cruciate ligament reconstruction broke at a higher rate (18/25-72%), whereas the uninjured collegiate athletes broke at a lower rate (4/25-16%). Conclusions: The in-line half-kneeling test is a reliable test between raters that can differentiate between groups expected to differ in MCCS.

2D AND 3D KINEMATICS DURING LATERAL STEP-DOWN TESTING IN INDIVIDUALS WITH ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION.

BACKGROUND: The lateral step-down test is an established clinical evaluation tool to assess quality of movement in patients with knee disorders. However, this test has not been investigated in individuals after anterior cruciate ligament reconstruction (ACLR) in association with quantitative 3D motion analysis. PURPOSES: The purpose of this study was to determine the strength of association between visually-assessed quality of movement during the lateral step-down test and 3D lower limb kinematics in patients with history of ACLR. A second purpose was to compare kinematics between subgroups based on the presence or absence of faulty alignments during the task. The final purpose was to compare visually-assessed quality of movement scores between box heights during lateral step-down testing. METHODS: Twenty subjects at least one year status post-ACLR (18 females, age of 24.5 ± 4.6 years and body mass index of 23.4 ± 2.3 kg/m2) performed the lateral step-down test unilaterally on the surgical limb atop four and six inch boxes. A board-certified orthopedic physical therapist scored overall quality of movement during the lateral step-down test using established criteria during 2D video playback. Lower limb kinematics were simultaneously collected using 3D motion capture. An alpha level of 0.05 was used for all statistical treatments. RESULTS: Overall 2D quality of movement score significantly correlated (r =0.47-0.57) with 3D hip adduction and hip internal rotation across box heights. Across box heights, the presence of faulty pelvic alignment differentiated a subgroup exhibiting less peak knee flexion, and the presence of faulty knee alignment differentiated a subgroup exhibiting greater peak hip adduction. The six inch box elicited worse quality of movement compared to the four inch box. CONCLUSIONS: These results suggest that visually-assessed quality of movement is associated with several kinematic variables after ACLR. 2D movement deviations at the pelvis appear to consistently relate to less knee flexion, and 2D deviations at the knee appear to suggest greater hip adduction. Generally, poorer quality of movement was observed for the six inch box height. Clinically, these data suggest that interventions targeting hip abductor and knee extensor strength and neuromuscular control may be useful in the presence of poor quality of movement during lateral step-down testing. LEVEL OF EVIDENCE: 2b.