title: Roller massager improves range of motion of plantar flexor muscles without subsequent decreases in force parameters.
abstract: BACKGROUND
  Limited dorsiflexion range of motion (ROM) has been linked to lower limb injuries. Improving limited ankle ROM may decrease injury rates. Static stretching (SS) is ubiquitously used to improve ROM but can lead to decreases in force and power if performed prior to the activity. Thus, alternatives to improve ROM without performance decrements are needed.
  
  
  OBJECTIVE
  To compare the effects of SS and self massage (SM) with a roller massage of the calf muscles on ankle ROM, maximal voluntary contraction (MVC) force F100 (force produced in the first 100 ms of the MVC), electromyography (EMG of soleus and tibialis anterior) characteristics of the plantar flexors, and a single limb balance test.
  
  
  METHODS
  Fourteen recreationally trained subjects were tested on two separate occasions in a randomized cross-over design. After a warm up, subjects were assessed for passive dorsiflexion ROM, MVC, and a single-limb balance test with eyes closed. The same three measurements were repeated after 10 minutes (min) of rest and prior to the interventions. Following the pre-test, participants randomly performed either SS or SM for 3 sets of 30 seconds (s) with 10s of rest between each set. At one and 10 min post-interventions the participants repeated the three measurements, for a third and fourth cycle of testing.
  
  
  RESULTS
  Roller massage increased and SS decreased maximal force output during the post-test measurements, with a significant difference occurring between the two interventions at 10 min post-test (p < 0.05, ES = 1.23, 8.2% difference). Both roller massage (p < 0.05, ES = 0.26, ~4%) and SS (p < 0.05, ES = 0.27, ~5.2%) increased ROM immediately and 10 min after the interventions. No significant effects were found for balance or EMG measures.
  
  
  CONCLUSIONS
  Both interventions improved ankle ROM, but only the self-massage with a roller massager led to small improvements in MVC force relative to SS at 10 min post-intervention. These results highlight the effectiveness of a roller massager relative to SS. These results could affect the type of warm-up prior to activities that depend on high force and sufficient ankle ROM.
  
  
  METHODS
  2c.
authors.affiliation: School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
authors.forename: Israel
authors.initials: I
authors.lastname: Halperin
authors.affiliation: School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
authors.forename: Saied Jalal
authors.initials: SJ
authors.lastname: Aboodarda
authors.affiliation: School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
authors.forename: Duane C
authors.initials: DC
authors.lastname: Button
authors.affiliation: National Research Centre for the Working Environment, Lersø Parkalle 105 DK 2100 Copenhagen, Denmark.
authors.forename: Lars L
authors.initials: LL
authors.lastname: Andersen
authors.affiliation: School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
authors.forename: David G
authors.initials: DG
authors.lastname: Behm
keywords: Dorsiflexion; electromyography; flexibility; self‐massage; strength