conditions? By Jonathan Luke Initial Purpose To investigate the - PowerPoint PPT Presentation

DOMS and EIMD: separate conditions? By Jonathan Luke

Initial Purpose • To investigate the acute effects of a high volume, low intensity workout on DOMS in eccentrically injured individuals. • Due to limitations of time, equipment, and protocol this treatment was not tested.

Case study • Instead, a case study was produced in which an individual exhibited clear positive symptoms of DOMS, without accompanying signs of EIMD.

“Differential diagnosis : the distinguishing of a disease or condition from others presenting with similar signs and symptoms .” (Merriam-Webster)

Background • Delayed Onset Muscle Soreness (DOMS) • The subjective experience of pain or soreness localized to a muscle group while at rest, on stretch, or during contraction. • Cause: Eccentric or unaccustomed exercise • Onset at 12 to 24 hours. • Peaks 1-3 days prior to onset and lasts 3-7 days • (Nosaka, 2002)

Background • Exercise Induced Muscle Damage (EIMD) • Causes: Eccentric or unaccustomed exercise • Symptoms: • Strength losses • Soreness (DOMS) • Stiffness • Edema • Structural disruption (Fig .1) Figure 1. Myofibril damage (Lieber, 1999) • Peak symptoms: 1-5 days prior to damage • Some symptoms measurable as long as 30 days • (Howatson, 2008)

DOMS and EIMD in Literature In reference to injuries resulting from eccentric exercise: “[E] ven a cursory perusal of the literature demonstrates that a wide variety of criteria for muscle injury has been employed, and that there has been no general agreement on the best methods for quantifying the pathology .” (Warren, 1999)

Laboratory Markers • Papers referring to • Papers referring to DOMS EIMD or damage • Soreness or pain • Soreness or pain • Strength (typically • Strength (typically MVC) MVC) • Joint angles and ROM • Joint angles and ROM • CK and other blood- • CK and other blood- borne proteins borne proteins

MRI evaluations • Limited number of studies using T2 relaxation times • All report • Significant increase in T2 relaxation times • Significant increase in delayed onset pain • Significant decreases in strength • Only one employs a submaximal exercise protocol • Reported high group variability in pain ratings and T2 times • (Evans, 1998)

Methods: Measurement Protocols • MRI • T2 relaxation times • Measure of muscle damage (Foley, 1999; Jayaraman, 2004) • Strength tests • Isometric MVC (Interpolated Twitch Technique at 90 degrees) • Performed on a Cybex Dynamometer • Perceived pain • 100mm Visual Analog Scale (VAS) Fig 3. A 100mm VAS. Raters place a mark upon the line best representing their pain along the spectrum.

Methods: Injury Protocols • Knee Extensions: Quadriceps • Intensity: 80% Concentric 1RM • 3 second eccentric lowering with one leg • Concentric raising with opposite leg • 5 sets / 2 min rest

Methods: Injury Protocols • Moderate protocol • Heavy protocol • Sets of 10 repetitions • Sets conducted to concentric failure • Did not reach failure • Produced DOMS • Did not produce • Subject P DOMS

Methods: Time Course • Baseline • Eccentric exercise protocol • 30 min post • 24 hr post • 48 hr post

Results: Pain Perceived pain ratings, VAS scores (mm). Subject Subject P Eccentric leg Concentric leg Pre 0 0 Post 8 0 24 56 2 48 60 2

Results: T2 relaxation times 60 Increases in T2 relaxation times in Subject P Relative increase from baseline (%) 40 Eccentric leg Concentric leg Jayaraman et al 20 0 Pre Post 24HR 48HR

Results: T2 relaxation times Subject P (Jayaraman, et al., 2004)

Results: Isometric strength Change in MVC torque relative to baseline in Subject P Percent of baseline torque (%) 100 90 Eccentric leg 80 Concentric leg 70 Jayaraman et al 60 50 Pre Post 24HR 48HR

Results: Voluntary activation Estimated voluntary activation in Subject P 100 Eccentric leg % Voluntary activation Concentric leg 90 80 70 Pre Post 24HR 48HR

Results: Potentiation Change in potentiated twitch torque relative to 120 baseline Percent of baseline torque (%) 100 Subject P 80 eccentric leg 60 Subject P concentric leg 40 20 0 Pre Post 24HR 48HR

Explanations • High inter-subject perceived pain and T2 variability • Reported in Evans, et al (1998) • May be statistical chance that a single subject showed no clear decrement in strength or increase in T2 relaxation times • Alternatively, • DOMS reproducible without muscle damage • DOMS and EIMD share an MOI but not a direct cause • A differential diagnosis for DOMS and EIMD may exist

Precedents • Evans, et al (1998) did not find a significant correlation between change in T2 and pain with muscle damage • In a review, Warren, et al (1999) found pain did not correlate well with muscle damage • Nosaka, et al (2002) found pain did not reflect the magnitude of muscle damage; suggesting, “ DOMS may not be directly related to muscle damage and subsequent inflammation .” • Yu, et al (2004) proposed myofibriller disruption associated with DOMS in literature represented remodeling, not damage

Implications • Further research is required • If the results can be replicated, may indicate a differential diagnosis exists between DOMS and EIMD • If replicated, DOMS in the absence of EIMD should be confirmed through other markers of structural damage (i.e. blood proteins, myofibriller damage) • If confirmed, DOMS in absence of EIMD should be investigated and described to aid in the understanding of causes and potential treatments

References • Differential diagnosis. (n.d.). In Merriam-Webster Online. Retrieved from http://www.merriam-webster.com/dictionary/differential%20diagnosis • Evans, G., Haller, R., Wyrick, P ., Parkey, R., Fleckenstein, J. (1998). Submaximal delayed- onset muscle soreness: correlations between MR imaging findings and clinical measures. Radiology . 208, 815-820. • Foley, J., Jayaraman, R., Prior, B., Pivarnik, J., & Meyer, R. (1999). MR measurements of muscle damage and adaptation after eccentric exercise. Journal of Applied Physiology . 87, 2311-2318. • Howatson, G. & Someren, K. (2008). The prevention and treatment of exercise-induced muscle damage. Sports Medicine. 38(6), 483-503. • Jayaraman, R., Reid, R., Foley, J., Prior, B., Dudley, G., Weingand, K., & Meyer, R. (2004). MRI evaluation of topical heat and static stretching as therapeutic modalities for the treatment of eccentric exercise-induced muscle damage. European Journal of Applied Physiology. 93, 30-38. • Liber, R., & Friden, J. (1999). Mechanisms of muscle injury after eccentric contraction. Journal of Science and Medicine in Sport. 2(3), 253-265. • Nosaka, K., Newton, M., Sacco, P . (2002). Delayed-onset muscle soreness does not reflect the magnitude of eccentric exercise-induced muscle damage. Scandinavian Journal of Medicine and Science in Sports. 12, 337-346. • Warren, G., Lowe, D., Armstrong, R. (1999). Measurement tools used in the study of eccentric contraction-induced injury. Sports Medicine . 27(1), 43-59. • Yu, J., Carlsson, L., Thornell, L. (2004). Evidence for myofibril remodeling as opposed to myofibril damage in human muscles with DOMS: an ultrastructural and immunoelectron microscopic study. Histochemistry and Cell Biology. 121, 219-227.