STUDY DESIGN: Cross-sectional experimental laboratory study. OBJECTIVES: To investigate the relationships between hip strength and hip kinematics, and between arch structure and knee kinematics during prolonged treadmill running in runners with and without patellofemoral pain syndrome (PFPS). BACKGROUND: Hip weakness can lead to excessive femoral motions that adversely affect patellofemoral joint mechanics. Similarly, foot mechanics, which are influenced by foot structure, are also known to influence patellofemoral joint mechanics. Thus, proximal and distal factors should be considered when studying individuals with PFPS. METHODS AND MEASURES: Twenty recreational runners with PFPS (5 male, 15 female) and 20 matched uninjured runners participated in the study. Hip abduction and hip external rotation isometric strength measurements were collected before and after a prolonged run, while the arch height index was recorded on all runners before the run. Lower extremity kinematic data were collected at the beginning and end of the run. Two-way repeated-measures analyses of variance (ANOVAs) were used for analysis. RESULTS: Both groups displayed decreases in hip abductor and external rotator strengths at the end of the run. The PFPS group displayed significantly lower hip abduction strength [(kg x cm)/body mass] compared to controls (PFPS group: begin 15.3, end 13.5; uninjured group: begin 17.3, end 15.4). At the end of the run, the level of association between hip abduction strength and the peak hip adduction angle for the PFPS group was statistically significant, indicating a strong relationship (r = -0.74). No other associations with hip strength were observed in either group. Arch height did not differ between groups and no significant association was observed between arch height and peak knee adduction angle during running. CONCLUSIONS: Runners with PFPS displayed weaker hip abductor muscles that were associated with an increase in hip adduction during running. This relationship became more pronounced at the end of the run. LEVEL OF EVIDENCE: Therapy, level 5.

J Orthop Sports Phys Ther. 2008;38(8):448-456, published online 15 April 2008. doi:10.2519/jospt.2008.2490

KEY WORDS: arch height index, hip abductor muscle strength, hip external rotator muscle strength, knee valgus

STUDY DESIGN: Resident's case problem. BACKGROUND: The role of premanipulative testing of the cervical spine is an area of controversy, and there are very few data to inform and guide practitioners on the use of ligamentous stability tests when assessing the upper cervical spine. DIAGNOSIS: A 23-year-old female was referred to physical therapy by a neurologist for the management of intractable headaches of possible musculoskeletal origin. Her Neck Disability Index score was 54% and she rated her headache pain from 3/10 to 9/10 on a Numerical Pain Rating Scale. She reported a 2-year history of intermittent lower extremity paresthesias without a known mechanism or current symptoms. She was treated in physical therapy for 11 visits with improvements in cervical range of motion, strength, and intensity of her headaches, but noted no change in the frequency of headaches. She was subsequently referred to the primary author for a second opinion and potential manual therapy interventions. Initial neurological screening examination for upper and lower motor neuron lesions was unremarkable. Assessment of the transverse ligament, using the anterior shear test in supine, brought on paresthesias in both feet and her toes. The paresthesias continued after the cessation of the test. The Sharp-Purser test performed in sitting, immediately after the transverse ligament test, abolished the paresthesias. She was then referred back to her primary care physician for further evaluation. Subsequent radiographs and magnetic resonance imaging revealed that the patient had a C2-C3 Klippel-Feil congenital fusion and os odontoideum. The patient was examined by a neurosurgeon who concluded that she was not a surgical candidate. Her neurological symptoms completely resolved, but she continued to have headaches. DISCUSSION: Os odontoideum is a clinically important condition, given that the mobile dens may render the transverse ligament incompetent, leading to atlantoaxial instability. Both the role and sequencing of upper cervical ligamentous testing is controversial. The results of this case report suggest that physical therapists should be cognizant of this condition and consider screening the upper cervical ligaments prior to manual or mechanical interventions to this region. LEVEL OF EVIDENCE:  Differential diagnosis, level 4.

J Orthop Sports Phys Ther. 2008;38(8):465-475, published online 27 June 2008. doi:10.2519/jospt.2008.2747

KEY WORDS: Klippel-Feil syndrome, manual therapy, neck, transverse ligament, upper cervical instability

SYNOPSIS: The process of evidence-based practice (EBP) guides clinicians in the integration of individual clinical expertise, patient values and expectations, and the best available evidence. Becoming proficient with this process takes time and consistent practice, but should ultimately lead to improved patient outcomes. The EBP process entails 5 steps: (1) formulating an appropriate question, (2) performing an efficient literature search, (3) critically appraising the best available evidence, (4) applying the best evidence to clinical practice, and (5) assessing outcomes of care. This second commentary in a 2-part series will review principles relating to steps 3 through 5 of this 5-step model. The purpose of this commentary is to provide a perspective to assist clinicians in interpreting results, applying the evidence to patient care, and evaluating proficiency with EBP skills in studies of interventions for orthopaedic and sports physical therapy. 

J Orthop Sports Phys Ther. 2008;38(8):485-501, published online 27 June 2008. doi:10.2519/jospt.2008.2725

STUDY DESIGN: Controlled laboratory study OBJECTIVES: To determine the effects of pulse duration and stimulation duration on the evoked torque after controlling for the activated area by using magnetic resonance imaging (MRI). BACKGROUND: Neuromuscular electrical stimulation (NMES) is commonly used in the clinic without considering the physiological implications of its parameters. METHODS AND MEASURES: Seven able-bodied, college students (mean ± SD age, 28 ± 4 years) participated in this study. Two NMES protocols were applied to the knee extensor muscle group in a random order. Protocol A applied 100-Hz, 450-microsecond pulses for 5 minutes in a 3-seconds-on 3-seconds-off duty cycle. Protocol B applied 60-Hz, 250-microsecond pulses for 5 minutes in a 10-seconds-on 20-seconds-off duty cycle. The amplitude of the current was similar in both protocols. Torque, torque time integral, and normalized torque for the knee extensors were measured for both protocols. MRI scans were taken prior to, and immediately after, each protocol to measure the cross-sectional area of the stimulated muscle. RESULTS: The skeletal muscle cross-sectional areas activated after both protocols were similar. The longer pulse duration in protocol A elicited 22% greater torque output than that of protocol B (P<.05). After considering the activated area in both protocols, the normalized torque with protocol A was 38% greater than that with protocol B (P<.05). Torque time integral was 21% greater with protocol A (P = .029). Protocol B failed to maintain torque at the start and the end of the 10-second activation. CONCLUSIONS: Longer pulse duration, but not stimulation duration, resulted in a greater evoked and normalized torque compared to the shorter pulse duration, even after controlling for the activated muscular cross-sectional areas with both protocols. LEVEL OF EVIDENCE: Therapy, level 5.

J Orthop Sports Phys Ther. 2008;38(8):508-516, published online 25 April 2008. doi:10.2519/jospt.2008.2734  

KEY WORDS: electrotherapy, MRI, NMES, quadriceps