Comparison of Continuous and Intermittent Ice Treatments After Muscle Contusion Injury Using Magnetic Resonance Imaging

Open Access
Fontaine, Eric Thomas
Area of Honors:
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Sayers John Miller Iii, Thesis Supervisor
  • Nicole M Mc Brier, Thesis Supervisor
  • Stephen Jacob Piazza, Honors Advisor
  • Giampietro Luciano Vairo, Faculty Reader
  • Ice
  • Icing
  • Magnetic Resonance Imaging
  • MRI
  • Injury
Comparison of Continuous and Intermittent Ice Treatments After Muscle Contusion Injury Using Magnetic Resonance Imaging Fontaine ET, McBrier NM, Neuberger T*, Vairo GL, Miller SJ: Athletic Training Research Laboratory, Department of Kinesiology, Department of Bioengineering*, The Pennsylvania State University, University Park, PA Context: Several recent studies have investigated cryotherapy and its role in the treatment of secondary injury. These studies have used widely varying ice treatment protocols in their study designs. Ice treatment protocols generally fall into two categories: continuous, in which ice is applied for a set length of time and then removed, and intermittent, in which ice is generally applied for shorter amounts of time, but is reapplied several times over the treatment course. To date, continuous and intermittent icing protocols have not been compared. Further research comparing continuous and intermittent icing protocols must be conducted to determine which method provides the greatest therapeutic benefits. Objective: To compare two icing protocols (continuous vs. intermittent) in a rat model following contusion of the gastrocnemius by using MRI T2 scans and volumetric calculations. It was hypothesized that the continuous icing protocol would induce less swelling as measured by a lesser change in limb volume and T2 relaxation time, which indicate that edema and inflammation have occurred. Design: T2 MRI scans were taken 0, 2, 4, and 6 hours after injury. The continuous icing protocol involved ice application throughout the entire 6-hour experiment; the intermittent icing protocol involved a pattern of 30 minutes of icing, followed by 60 minutes of no ice, completed 4 times over the 6-hour experiment. T-tests were used to analyze statistical differences between icing protocols and limb status. Setting: Controlled laboratory environment. Subjects: 20 male Wistar rats (272g ± 29 g) procured from Harlan-Sprague Dawley (Indianapolis, IN). Interventions: Icing protocol (continuous vs. intermittent), limb status (healthy vs. injured) and time point (0, 2, 4, and 6 hours after injury). Main Outcome Measures: T2 signal was measured throughout the experiment to observe fluid accumulation in the limb due to edema and hemorrhage. Limb volume changes were calculated using AMIRA 3D imaging software (Mercury Computer Systems, Inc., Chelmsford, MA, USA). Data were analyzed using T-Tests to identify within and between group differences. Results: Significant differences existed between the injured and healthy limbs in both protocols except at baseline for both T2 and volume. A significant difference in T2 was found between the two protocols at 2 hours and over the 2-to-4 hour timespan post-injury. While continuous T2 relaxation time significantly increased over all timespans, intermittent T2 relaxation time change was not significant over the 2-to-4 and 4-to-6 hour timespans. Significant changes in volume occurred in the intermittent protocol until the 4-to-6 hour timespan, while significant changes occurred over all timespans in the continuous timespan. A significant difference in limb volume occurred between the two protocols in the injured limb over the 4-to-6 hour timespan. Conclusion: Our findings suggest that no statistically significant difference exists between the two icing protocols, although different swelling patterns may have occurred between the two protocols. This indicates that the intermittent protocol would be a better therapeutic choice, as it can elicit the same swelling responses as continuous icing while placing a patient at a lower risk for developing cold-related injuries. Furthermore, because of its less extreme icing schedule, the intermittent protocol may be superior in maintaining patient compliance. Word Count: 512