Study Design: Case control design. Objectives: To investigate whether differences exist in lower extremity muscle strength and soft tissue length between patients with patellofemoral pain syndrome (PFPS) and age- and gender-matched control subjects. Background: Based on our clinical experience and emerging data, impairments such as muscular weakness surrounding the hip and limited flexibility of key lower extremity muscles may be important impairments to consider in the conservative management of PFPS. Methods and Measures: Thirty patients with PFPS and 30 age- and gender-matched controls without PFPS (17 females and 13 males in each group) participated in the study. Data were collected during 1 testing session by an examiner not blinded to group assignment. Demographic, health history, physical activity levels, and pain and function were assessed using patient-completed measures. Physical examination measures included assessment of hip external rotation strength, hip abduction strength, length of the iliotibial band/tensor fascia lata complex, gastrocnemius length, soleus length, and quadriceps and hamstrings muscles length. Results: Patients with PFPS demonstrated significantly less flexibility of the gastrocnemius, soleus, quadriceps, and hamstrings compared to healthy control subjects. No differences existed in flexibility of the iliotibial band/tensor fascia lata complex and strength of the hip external rotators and abductors. Multivariate stepwise discriminant analysis identified gastrocnemius length, hip abduction strength, and soleus length as being able to distinguish between patients with PFPS and healthy individuals without PFPS. Conclusion: This study suggests that further research is warranted regarding the association of these impairments of muscle strength and soft tissue length in patients with PFPS.

J Orthop Sports Phys Ther. 2005;35(12):793-801.

Key Words: ankle plantar flexors, anterior knee pain, case control, hip abduction, hip external rotation

Study Design: Fine-wire EMG rotator cuff onset time analysis in 2 matched groups of throwers with and without pain.
Objective: To identify if there is a difference in the activation patterns of the rotator cuff muscles during a rapid shoulder external rotation task between throwers with and without pain.
Background: The coordinated action of the rotator cuff is recognized as essential for glenohumeral joint control in the throwing athlete. Identification of abnormalities occurring in muscle activation patterns for injured athletes is relevant when prescribing rehabilitative exercises.
Methods and Measures: Twelve throwers with shoulder pain were compared to a matched group of 11 asymptomatic throwers. Participants were matched for age, height, body mass, and habitual activity. Fine-wire EMG electrodes were inserted into the subscapularis, supraspinatus, and infraspinatus. EMG activity was measured during a reaction time task of rapid shoulder external rotation in a seated position. The timing of onset of EMG activity was analyzed in relation to visualization of a light (reaction time) and to the onset of infraspinatus activity (relative latency).
Results: In the group with shoulder pain, the onset of subscapularis activity was found to be significantly delayed (reaction time, P = .0018; relative latency, P = .0005) from the onset of infraspinatus activity when compared to the control group.
Conclusions: The presence of shoulder pain in these athletes was associated with a difference in the onset of subscapularis EMG activity during a rapid shoulder external rotation movement. This was an initial step in the understanding of the joint protection mechanisms of the glenohumeral joint and the problems that occur in throwers. This information may assist in providing future guidelines for more effective rehabilitation and prevention strategies for this condition.

J Orthop Sports Phys Ther. 2005;35(12):812-820.

Key Words: baseball, electromyography, throwing

Study Design: Experimental 3-factor design with repeated measures on all factors.
Objectives: The purpose of this study was to determine the effectiveness of 3 prophylactic hyperextension elbow braces on limiting active and passive elbow extension before and after exercise.
Background: Prophylactic hyperextension elbow braces are used to protect the joint against excessive extension, but their effectiveness for this purpose has not been determined.
Methods and Materials: Twenty Division I intercollegiate football players (mean ± SD age, 20.2 ± 1.3 years; mean ± SD height, 184.4 ± 9.9 cm, mean ± SD mass, 102.9 ± 22.0 kg) completed all phases of the study. The Breg Functional Elbow Brace, PRO 470 Kendall Elbow Brace, and DonJoy Elbow Guard were tested both actively and passively before and after an isokinetic exercise session on a Biodex Multi-Joint Testing and Exercise Dynamometer. For all tests, the braces were set at a 30° flexion limit angle. The exercise session consisted of 1 set of reciprocal elbow extension and flexion at an angular velocity of 360°/s, totaling 1627 J of work.
Results: None of the braces limited elbow extension to the 30° flexion limit. However, all of the braces were successful in preventing the elbow from reaching the vulnerable position of hyperextension. The Breg Functional Elbow Brace was the most effective for limiting elbow extension near its set angle, followed by the DonJoy Elbow Guard, and the PRO 470 Kendall Elbow Brace across all test conditions.
Conclusion: The braces’ effectiveness to limit motion is enhanced when limits are set higher than the desired angle of the protected motion.

J Orthop Sports Phys Ther. 2005;35(12):837-843.

Key Words: dislocation, elbow bracing, functional bracing, upper extremity bracing

Index by subject of all manuscripts published by the Journal during 2005.

J Orthop Sports Phys Ther. 2005;35(12):868-876.