Effect of Exhaustive Exercise on Lumbopelvic-Hip Complex Stability, Muscle Activity, and Movement Patterns.

This study aimed to evaluate the effect of exhaustive exercise on lumbopelvic-hip complex (LPHC) muscle activity, stability, and single-leg squat kinematics. Twenty-two healthy participants (12 females, 23.5 ± 3.1 years) were recruited. LPHC stability was measured by number of errors committed during a seated trunk control test (STCT). Surface electromyography recorded muscle activity of rectus abdominis (RA), external oblique, internal oblique (IO), erector spinae, and gluteus medius during the STCT and single-leg squat, and was normalized to peak activity during the task. Two-dimensional motion analysis quantified frontal and sagittal plane kinematics of the trunk, hip, and knee. Following exhaustive exercise, STCT performance worsened (number of errors: pre: 5.5 (interquartile range (IQR) = 1.4-9.0), post: 8.0 (IQR = 3.6-11.3), p = 0.026.), RA activity increased during the single-leg squat (pre: 42.1 (IQR = 33.6-48.5)%, post: 61.1 (IQR = 39.4-156.7 %, p =.004), and participants displayed less hip and knee flexion (hip: pre: 72.4 ± 22.1°; post: 66.2 ± 22.5°, p =.049; knee: pre: 72.4 ± 15.4°; post: 67.4 ± 18.2°, p =.005). Full-body exhaustive exercise negatively affected isolated LPHC stability and resulted in greater RA activity during the single-leg squat. Hip and knee flexion decreased during a single-leg squat after exhaustive exercise which could indicate decreased athletic performance, but changes in the quality of movement during other tasks should be further investigated.

Confidence and Knowledge of Athletic Trainers in Managing Patellofemoral Pain.

CONTEXT: Patellofemoral pain (PFP) is prevalent and challenging to manage. Most patients with PFP are unsatisfied with their knee function at 6 months after treatment and report ongoing pain up to 16 years after diagnosis. The confidence and knowledge of athletic trainers (ATs) in providing evidence-based care to people with PFP is unknown. OBJECTIVE: To investigate the confidence and knowledge of ATs in the diagnosis, risk factors, prognosis, and treatment with current evidence for PFP. DESIGN: Cross-sectional study. SETTING: Online survey. PATIENT OR OTHER PARTICIPANTS: A random sample of 3000 ATs were invited to participate; 261 completed the survey (10% participation rate, 88% completion rate). MAIN OUTCOME MEASURES(S): We surveyed AT demographics, confidence in PFP management, and knowledge related to diagnosis, risk factors, prognosis, and treatment. The confidence and knowledge of ATs in managing PFP was assessed. Their beliefs about evidence were compared with the available evidence (ie, consensus statements, position statements, systematic reviews). RESULTS: Of the ATs surveyed, 91% were confident that their management of PFP aligned with the current evidence, but only 59% were confident in identifying risk factors for PFP development. In addition, 91% to 92% of ATs agreed that quadriceps and hip muscle weakness were risk factors for PFP, which aligns with the current evidence for the former but not the latter. Moreover, 93% to 97% of ATs' responses related to therapeutic exercise aligned with current evidence. However, 35% to 48% supported the use of passive treatments, such as electrophysical agents and ultrasound, which did not align with the current evidence. CONCLUSIONS: Most ATs were aware of supporting evidence for therapeutic exercise in PFP management and were confident providing it, creating a strong foundation for evidence-based care. However, varying levels of awareness of the evidence related to risk factors and passive treatments for PFP highlight the need for professional development initiatives to better align ATs' knowledge with the current evidence.

Relationship between lumbopelvic-hip complex stability, muscle activity, and 2-dimensional kinematics of the trunk and lower extremity.

OBJECTIVES: To observe isolated lumbopelvic-hip complex (LPHC) stability and muscle activity using the Seated Trunk Control Test (STCT) and evaluate the relationship between LPHC stability and 2-dimensional kinematics during movements. DESIGN: Descriptive Study. SETTING: Laboratory. PARTICIPANTS: 22 healthy participants (12F, 10M, 23.5 ± 3.1yrs, 173.0 ± 9.0 cm, 76.1 ± 10.7 kg). MAIN OUTCOME MEASURE(S): Time to first error and number of errors, and muscle activity of the abdominals, erector spinae, and gluteus medius were recorded during the STCT. Lateral trunk movement, hip and knee frontal plane projection angles, hip and knee flexion during single leg squats and single leg drop vertical jumps were measured. Pearson r correlations were calculated among STCT performance, muscle activity, and 2-dimensional kinematics. RESULTS: Number of errors was moderately correlated to hip and knee flexion during single leg squatting (r = 0.456-0.649, p < 0.05). Number of errors and time to first error were moderately correlated to knee-frontal plane projection angle and hip flexion respectively during single leg drop vertical jumping (r = 0.463-0.515, p < 0.05). CONCLUSIONS: Decreased LPHC stability relates to decreased sagittal plane motion during single leg squatting and increased frontal plane motion during single leg drop vertical jumping. Pairing the STCT with 2-dimensional kinematic analysis can demonstrate influence of LPHC function.