Eccentric exercise is able to mechanically engage muscle, initiating strain-sensing molecules that promote muscle recovery by inducing beneficial adaptations in neural activity and muscle morphology, 2 critical components of muscle function that are negatively altered after injury. However, due to misinterpreted mathematic modeling and in situ and in vitro stretch protocols, a dogma that exposing muscle to eccentric exercise is associated with injury has been perpetuated in the literature. In response, clinicians have been biased toward using concentric exercise postinjury to improve the recovery of muscle function. Unfortunately, this conventional approach to rehabilitation does not restore muscle function, and reinjury rates remain high. Here, the authors present experimental evidence and theoretical support for the idea that isolated eccentric exercise is ideally suited to combat muscle inhibition and muscle strains and is an attractive alternative to concentric exercise.
Lindsey K. Lepley and Timothy A. Butterfield
Timothy A. Butterfield and Lindsey K. Lepley
Timothy L. Uhl, Thomas Rice, Brianna Papotto and Timothy A. Butterfield
The role of the rotator cuff is to provide dynamic stability to the glenohumeral joint. Human and animal studies have identified sarcomerogenesis as an outcome of eccentric training indicated by more torque generation with the muscle in a lengthened position.
The authors hypothesized that a home-based eccentric-exercise program could increase the shoulder external rotators’ eccentric strength at terminal internal rotation (IR).
Prospective case series.
Clinical laboratory and home exercising.
10 healthy subjects (age 30 ± 10 y).
All participants performed 2 eccentric exercises targeting the posterior shoulder for 6 wk using a home-based intervention program using side-lying external rotation (ER) and horizontal abduction.
Main Outcome Measures:
Dynamic eccentric shoulder strength measured at 60°/s through a 100° arc divided into 4 equal 25° arcs (ER 50–25°, ER 25–0°, IR 0–25°, IR 25–50°) to measure angular impulse to represent the work performed. In addition, isometric shoulder ER was measured at 5 points throughout the arc of motion (45° IR, 30° IR, 15° IR, 0°, and 15° ER). Comparison of isometric and dynamic strength from pre- to posttesting was evaluated with a repeated-measure ANOVA using time and arc or positions as within factors.
The isometric force measures revealed no significant differences between the 5 positions (P = .56). Analysis of the dynamic eccentric data revealed a significant difference between arcs (P = .02). The percentage-change score of the arc of IR 25–50° was found to be significantly greater than that of the arc of IR 0–25° (P = .007).
After eccentric training the only arc of motion that had a positive improvement in the capacity to absorb eccentric loads was the arc of motion that represented eccentric contractions at the longest muscle length.
Timothy Martinson, Stephen A. Butterfield, Craig A. Mason, Shihfen Tu, Robert A. Lehnhard and Christopher J. Nightingale
Purpose: The purposes of this study were to examine the performance on the progressive aerobic cardiovascular endurance run (PACER) test in children with and without attention-deficit hyperactive disorder (ADHD) over the course of a school year, and also to investigate the possible influence of age, sex, school sport participation, and body mass index on results. Methods: Utilizing a repeated measures design, 892 middle school children aged 11–14 years (mean = 12.25, SD = 0.94) including 55 children with ADHD participated. While controlling for age, sex, sports participation, and body mass index, children were tested on the PACER 3 times during the school year. Procedures specified in the FITNESSGRAM test manual were explicitly followed. Hierarchical linear modeling was applied to analyze the data. Results: Children with ADHD performed 8.6 fewer laps at intercept (baseline), than did healthy children without ADHD (t 878 = −6.20, P < .001). However, no significant differences emerged for time (slope). In addition, no significant interactions were found for ADHD with age, sex, sports participation, or body mass index. Conclusion: A diagnosis of ADHD, independent of selected predictor variables, explained lower PACER performance.
Emily R. Hunt, Shelby E. Baez, Anne D. Olson, Timothy A. Butterfield and Esther Dupont-Versteegden
Massage is a common therapeutic modality utilized by clinicians in a variety of settings to help treat injuries, reduce pain, and return function to patients. Massage benefits the patients both psychologically and physiologically, as patients report less pain and anxiety along with better mood and even decreased blood pressure following massage. Additionally, on the cellular level, massage has the ability to modulate the damaging inflammatory process and, in some cases, influence protein synthesis. Although massage has not been linked to a rehabilitation theory to date, this paper will propose how massage may influence fear-avoidance beliefs, or the patient’s inability to cope with pain that then leads to a pain tension cycle. Pain will often result in use avoidance, which creates muscle tension that further exacerbates the pain. Massage can affect the Fear-Avoidance Model because the beneficial effects of massage can break the cycle by either relieving the patient’s pain or eliminating the muscle tension. A modified Fear-Avoidance Model is presented that conceptualizes how pain and fear-avoidance lead to tension and muscle dysfunction. Massage has been incorporated into the model to demonstrate its potential for breaking the pain tension cycle. This model has the potential to be applied in clinical settings and provides an alternate treatment to patients with chronic pain who present with increased levels of fear-avoidance beliefs.