Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control

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Skyline - The Big Sky Undergraduate Journal Volume 3 Issue 1 Article 1 2015 Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control Cali A.

1 Skyline - The Big Sky Undergraduate Journal Volume 3 Issue 1 Article Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control Cali A. VanValkenburg University of Montana, calivv@gmail.com Britt Dickman University of Montana, brittmakel@hotmail.com Follow this and additional works at: Part of the Arts and Humanities Commons, Business Commons, Education Commons, Life Sciences Commons, Medicine and Health Sciences Commons, and the Social and Behavioral Sciences Commons Recommended Citation VanValkenburg, Cali A. and Dickman, Britt (2015) "Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control," Skyline - The Big Sky Undergraduate Journal: Vol. 3 : Iss. 1, Article 1. Available at: This Research Article is brought to you for free and open access by Skyline - The Big Sky Undergraduate Journal. It has been accepted for inclusion in Skyline - The Big Sky Undergraduate Journal by an authorized editor of Skyline - The Big Sky Undergraduate Journal.

2 Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control Acknowledgments The University of Montana Davidson Honors College funded this study. Thanks to Dr. Valerie Moody for serving as our faculty mentor throughout this project. This research article is available in Skyline - The Big Sky Undergraduate Journal:

3 VanValkenburg and Dickman: Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control Introduction Playing at a high level of competition places many physical demands on the body. Throughout an athletes life, they are taught to take care of their body in order to perform at their best. Many athletes condition, practice, stretch, and lift to optimize their performance. The idea of gaining flexibility to help prevent injury and enhance performance has been preached throughout any athletes career. 1 Stretching has become a universally accepted practice used to increase flexibility, reduce muscle injury, and improve performance. Many athletes stretch as a means to warm up before practice and games. The popularity of this practice is in part due to the main causes of musculoskeletal injuries, which include lack of range of motion and muscle stiffness. 2 Stretching effectively reduces both of these risk factors, but the current literature regarding the effects static stretching has on injury reduction is inconclusive. A recent systematic review found preliminary evidence advocating that a static stretching routine may in fact help reduce the number of injuries. 2 However, the influence that static stretching has on postural control and function remains to be seen. In addition to stretching, modalities, such as ultrasound are used to increase collagen extensibility, therefore increasing range of motion (ROM). Therapeutic ultrasound is commonly used for treating sports-related musculoskeletal injuries such as tendinopathies, muscle spasms, and muscle strains. 3 Both thermal and non-thermal effects can be achieved within the tissue at deep and superficial levels. The thermal effects include increase extensibility of collagen, reduce muscle spasm, and increase blood flow within the target tissue. 4 When the goal is to increase tissue temperature, there are three types of heating: mild heating, moderate heating, and vigorous heating. 3 This study focused on the effects of vigorous heating on the targeted tissue. Published by Skyline - The Big Sky Undergraduate Journal,

4 Skyline - The Big Sky Undergraduate Journal, Vol. 3 [2015], Iss. 1, Art. 1 The premise for this study was to see if combining a stretching routine with ultrasound would improve ROM and postural control. Past research has produced inconclusive results regarding the effects of ultrasound and its correlation with increased range of motion. This study aimed to produce conclusive evidence on how effective ultrasound is with increasing range of motion, which in return should decrease the rate of injury. 5 The goal was to assess the effectiveness of ultrasound and static stretching on hip flexor range of motion, with the hope that this research would guide future clinical decision-making regarding the treatment of hip flexor strains. Methods Design A repeated measure design was used whereby all participants completed three trials over a two-week period. Each trial day, participants were assigned to a randomly selected treatment. A 48-hour window in-between each trial was ensured to avoid carryover of treatment effects. The dominant leg of each participant was used in all trials. Participants Six students from the Professional Athletic Training program at the University of Montana volunteered to participate in this study. Three males and three females between the ages of 18 and 30 were studied. All of the participants were moderately active in addition to their activities of daily living. Prior to this study, all participants were screened for a lower extremity injury. Any participant that reported an injury within the past six months was disqualified from the study. Participants were instructed to refrain from activity 24 hours prior to their trials. Lower extremity stretching was also not allowed for the period of the study. 2

5 VanValkenburg and Dickman: Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control Instruments Ultrasound The Forte CB- 450 ultrasound machine was used for the treatments in this study. Conductor transmission gel (Chattanooga Group in Hixon, TN) was used as the medium in every ultrasound treatment. Each participant used the same parameters, a 4 cm 2 sound head at 1 mhz, 1.0 w/cm 2, 100% duty cycle for 15 minutes to induce vigorous heating, raising the tissue temperature 7.2 degrees Fahrenheit above baseline. 3 An outline, double the size of the ultrasound head, was placed over the hip flexor muscles on the dominant leg of the participant. One person conducted all ultrasound treatments to ensure consistency in treatments. The sound head was moved in circular motions at a rate of 3-4 cm per second. 3 If the heat was uncomfortable for the participant, the intensity was adjusted accordingly. Goniometer A 12 goniometer (Whitehall Manufacturing in City of Industry, CA) was used to obtain the range of motion measurement in this study. Active hip extension was measured with the participant lying prone. The axis of the goniometer was placed on the greater trochanter of the femur on the participant s dominant leg. 6 The stationary arm was placed parallel on the trunk, and the movement arm was placed on the thigh in line with the lateral femoral condyle. 6 Goniometer measurements were taken while the participant performed active range of motion into hip extension using the dominant leg. Three measurements were taken and an average was calculated for every trial. Published by Skyline - The Big Sky Undergraduate Journal,

6 Skyline - The Big Sky Undergraduate Journal, Vol. 3 [2015], Iss. 1, Art. 1 Stretching The Thomas stretch and lunge stretch were used in this study. The Thomas stretch is performed with another person who aids the stretch. The lunge stretch was completed alone. Participants who were assigned a stretching routine for their treatment day were instructed to complete the Thomas stretch first and then the lunge stretch. During the Thomas stretch, the participant laid supine on the treatment table with their lower extremities hanging off the edge. The dominant leg was left hanging while the participant pulled their non-dominant leg to their chest in full knee flexion. One person (B.D.) pushed the participants dominant leg inferiorly at the knee, while simultaneously pushing their ankle posterior. The stretch was held for 30 seconds, two times. The participants were then instructed to do the lunge stretch. There was no assistance needed. Kneeling on the dominant leg and placing the non-dominant leg anterior to the body with the knee and the hip in 90 degrees of flexion is how the participants were instructed to execute the lunge stretch. The participants leaned into the non-dominant leg, creating a stretch in the hip flexors of the dominant leg. The stretch was completed twice, holding it each time for 30 seconds. Star Excursion Balance Test In order to examine the effectiveness of static stretching and ultrasound, the Star Excursion Balance Test (SEBT) was used as a functional assessment. The SEBT is used clinically to assess dynamic postural control. Postural control tests are used most often to evaluate the chance that an injury could occur, the discrepancy that can appear after an injury, and the progress a person is making following an injury. The measure of how far a participant can reach without losing their base of support in the middle of the star is how the postural control component is measured. 7 The SEBT has a high inter-rater reliability as well as 4

7 VanValkenburg and Dickman: Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control good indications of dynamic postural control. It is easy to use and most importantly cost effective for researchers. 8 During the SEBT, the participants are asked to stand on their dominant leg in the center of a pre-made star pattern. They were asked to reach with their nondominant leg as far as they could along the star pattern. Reaching towards eight different angles of the star, the participant was asked to non-weight bear with the non-dominant leg during this test. 8 A mark was placed where the participant would touch down at each angle. Concluding each trial, a measurement from the center of the star out to each mark was taken. Three trials were completed, and the measurements from each trial were averaged. Procedures Upon receiving IRB approval, each participant signed an informed consent during the first meeting. Each participant s height and weight was obtained prior to beginning research. An initial base line measurement of active hip extension was taken prior to each research day. One person took all goniometer measurements to minimize measurement error and to increase reliability. A baseline SEBT test was also obtained prior to each research day. Three measurements were obtained and averaged. Prior to each treatment, the participant randomly selected one of the three trials. The three trials consisted of: stretching alone, ultrasound alone, or stretching and ultrasound combined. After the participant received ultrasound and stretched, we took their measurements for range of motion and the SEBT within ten minutes. Ultrasound Participants who came in for only the ultrasound treatment were first instructed to lie prone on the treatment table, for goniometry measurements. Daily Published by Skyline - The Big Sky Undergraduate Journal,

8 Skyline - The Big Sky Undergraduate Journal, Vol. 3 [2015], Iss. 1, Art. 1 baseline measurements of active hip extension ROM were recorded. The SEBT was also performed to provide daily baseline postural control measurements. The participant would then lie supine with their dominant leg hanging off the lateral edge of the table. A stool was placed under the dominant foot to provide participant comfort. Before beginning the ultrasound treatment, a pre-made stencil was placed over the treatment area and was outlined. The parameters for the ultrasound treatment are listed previously. Immediately following the treatment, active hip extension ROM measurements were taken and recorded. Then, the participant performed the SEBT and these results were also recorded. Stretch Participants who came in for only a stretching treatment were instructed to lie prone on the table. A daily baseline of active hip extension ROM was recorded, as well as a daily baseline to assess postural control (SEBT). The participant completed the Thomas stretch and the lunge stretch, following parameters listed above. Immediately following the treatment, another active hip extension ROM measurement was recorded. Then, the participant performed the SEBT. The results were recorded. Ultrasound and Stretch Participant who came in for ultrasound and stretch were instructed to lie prone on the table. A daily baseline of active hip extension ROM was recorded, as well as a daily baseline to assess postural control (SEBT). The participant would then lie supine with their dominant leg off the lateral edge of the table. A stool was placed under the dominant foot to provide participant comfort. Before beginning the ultrasound treatment, a pre-made stencil was placed over the treatment area and was outlined. The parameters for the ultrasound treatment are listed above. The participant then completed the Thomas stretch and the lunge 6

9 VanValkenburg and Dickman: Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control stretch, using the parameters listed above. Immediately following the treatments, another active hip extension ROM measurement was recorded. The participant then performed the STAR Excursion Balance Test, and the results were recorded. Data Analysis Descriptive statistics were calculated for each subject s age, height, weight, STAR excursion balance test, and range of motion measurements. A 2 x 3 repeated measures (time x condition) ANOVA was used to evaluate significance where alpha was set a priori at If significant interactions were found, pairwise comparisons were run using a Bonferonni adjustment. Microsoft Excel 2013 and IBM SPSS version 22 were used to analyze the data. Results The 2 X 3 repeated measures ANOVA revealed no statistical significance for hip extension and SEBT (p=0.79 and p=0.13 respectively). The mean scores for combo, stretch, and US for hip ROM pre and post trials are shown in Figure 1. The combo and US trials both showed a decrease of 0.83 cm and 0.08 cm respectively for hip ROM. The stretch trial showed the only increase of 0.64 cm for hip ROM, but it was not a big enough increase to have significance. Figure 2 shows the mean scores for combo, stretch, and US for SEBT composite scores. The composite score used the anterior, posterolateral, and posteromedial scores from the SEBT. 8 An increase of 1.70 cm and 1.78 cm was shown for the US and stretch trials respectively, and a decrease of 0.71 cm was shown for the combo trial. Therefore, the statistical analysis showed no significant difference in any trial. Discussion Many clinicians use ultrasound as a therapeutic modality to heat tissues, and promote healing. Ultrasound is also used to improve ROM by increasing Published by Skyline - The Big Sky Undergraduate Journal,

10 Skyline - The Big Sky Undergraduate Journal, Vol. 3 [2015], Iss. 1, Art. 1 collagen extensibility within the desired tissue. This research intended to determine ultrasound s effects on increasing ROM and postural control in the hip flexors and how these effects could be enhanced by a stretching routine. The results of this study were found to be inconclusive for all three trials performed. What follows is a discussion regarding first the stretching trial, second the ultrasound trial, and finally the combination trial. It is believed by many that stretching routines increase ROM but the results from this research showed no statistical significance that stretching improved hip extension. There was actually a decrease in goniometry measurements following the static stretching routine. There was a small increase in SEBT scores, but the increase was not enough to be clinically relevant. A systematic review found some initial evidence that a static stretching routine could in fact decrease injury. 2 However, these results also show that stretching alone would not increase dynamic postural control. A randomized control trial found increases in hip extension following a passive and active stretching routine. This study was conducted over the course of three and six-week trials and found increases in hip extension. 9 This study may have produced different results because of the length of time allotted to conduct research, allowing the benefits of stretching to be seen. Other modalities have been used alongside stretching to facilitate improvements in ROM pre-event. Ultrasound when used to vigorously heat tissue has been shown to improve ROM. The results showed no increase in goniometry measurements, and only slight increases in SEBT scores. Putting the participant s hip flexors in a stretched position was utilized to improve the effects of the ultrasound treatment and lengthen the stretching window. This window is a phase during vigorous heating where the muscles can achieve their greatest extensibility. It is suggested that joint mobilizations and stretching are done immediately following an ultrasound treatment; to ensure that the stretching window is still open. 3 Despite 8

11 VanValkenburg and Dickman: Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control these extra efforts the outcome showed no statistical evidence that ultrasound effectively increased hip flexor ROM. The effects ultrasound had on postural control also remains to be seen because of the lack of clinical significance found in the SEBT data. The focus of this study was to see if the combination of these modalities, stretching and ultrasound would prove a different outcome. This was not the case: decreases in both goniometry measurements and SEBT scores were found in the combination group. If this study could ve been performed over a longer period of time there may have been some clinically significant numbers from the combination trial or the stretching trial. In addition, if a more superficial muscle group was to be studied there may have also been more noteworthy results. Limitations The first limitation to our study was the small sample size. Participants could only be selected from the athletic training classes at the University of Montana. Many of the participants were young and healthy individuals, limiting the diversity in the study. There was also no means to measure the rise in tissue temperature following the ultrasound treatment. Therefore, there was no way to know if specific tissue was achieving the desired raise in temperature. Another limitation was that the study could only be conducted in the evening; therefore, the participants muscles could have been fatigued from their daily activities. Rest times were also not enforced in our stretching trials and during the SEBT trials. During the SEBT trials rest time between each test was based on participant comfort and was not designated. This could ve affected how far they could reach because they may have been fatigued when completing their second and third tests. A rest time of 10 seconds was designated between the stretching trials. This was not based upon past research but was enforced for consistency. Published by Skyline - The Big Sky Undergraduate Journal,

12 Skyline - The Big Sky Undergraduate Journal, Vol. 3 [2015], Iss. 1, Art. 1 When collecting numbers for hip extension the participants were instructed to lie prone, but some participants did not fully lie down but stayed up on their elbows. This could ve decreased their hip extension. There was also not a second researcher to enforce correct form when completing hip extension, to ensure that the hips and back stayed on the table. This could ve increased hip extension. Overall, hip extension was measured as consistently as possible but errors may have occurred. Lastly, participants were not supposed to exercise 24 hours prior to research trials. The majority followed this stipulation, but we had no way of confirming this. The effects of working out could ve decreased hip extension and their SEBT scores due to soreness of muscles. Working out could ve also increased hip extension, if the participants were stretching their lower extremity during their workouts. Future Research If further research were to be conducted, a larger sample size would be desirable. This would give a more diverse group of participants. Ideally, this research would be best conducted with an athletic population, people currently participating in a competitive sport. Research would also have to be carried out over a longer period of time. This would enable the results to be more conclusive, giving a better idea of specific trends. Lastly, using different ultrasound parameters on different subjects could give a better idea on what specific parameters deep heat the hip-flexors best to achieve the desired goal. Conclusion This study aimed to produce conclusive results regarding the effects of static starching and ultrasound on postural control and function. This study produced inconclusive results in all three trials, static stretching alone, ultrasound alone, and the combination of the two modalities. Further research needs to be 10

13 VanValkenburg and Dickman: Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control completed in order to better assess the effects of ultrasound and stretch as they relate to ROM, postural control, and overall function. References 1. Thacker SB, Gilchrist J, Stroup DF, Kimsey CD. The Impact of Stretching on Sports Injury Risk: A Systematic Review of the Literature. Med. Sci Sports Exercise. 2004;36(3): Small K, Mc Naughton L, Matthews M. A Systematic Review into the Efficacy of Static Stretching as Part of a Warm-Up for the Prevention of Exercise-Related Injury. Research in Sports Medicine: An International Journal. 2008;16(3): doi: / Knight KL, Draper DO. Therapeutic Modalities: The Art and Science. Baltimore, MD: Lippincott Williams & Wilkins; Speed CA. Therapeutic Ultrasound in Soft Tissue Lesions. Rheumatology. 2001;40: Reed BV, Ashikaga T, Fleming BC, Zimny NJ. Effects of ultrasound and Stretch on Knee Ligament. Journal of Orthopaedic & Sports Physical Therapy. 2000;30(6): doi: /jospt Starkey C, Brown SD, Ryan J. Examination of Orthopedic and Athletic Injuries. Philadelphia, PA: F.A. Davis Company; Brumitt J. Assessing Athletic Balance with the Star Excursion Balance Test. NSCA s Performance Training Journal. 7(3): Gribble PA, Kelly SE, Refshauge KM, Hiller CE. Interrater Reliability of the Star Excursion Balance Test. Journal of Athletic Training. 2013; 48(5): doi: / Published by Skyline - The Big Sky Undergraduate Journal,

14 Skyline - The Big Sky Undergraduate Journal, Vol. 3 [2015], Iss. 1, Art Winters MV, Blake CG, Trost JS, Marcello-Brinker TB, Lowe L, Garber MB, Wainner, RS. Passive Versus Active Stretching of Hip Flexor Muscles in Subjects With Limited Hip Extension: A Randomized Clinical Trial. Journal of the American Physical Therapy Association. 2004; 84(5): Figure 1. Hip Extension ROM following Treatment 12

15 VanValkenburg and Dickman: Comparing the Effects of Ultrasound and Stretching on Hip Flexor Flexibility and Postural Control Hip Extension ROM Following Treatment 60 Es)mated Marginal Means Pre Post Combo US Stretch Published by Skyline - The Big Sky Undergraduate Journal,

16 Skyline - The Big Sky Undergraduate Journal, Vol. 3 [2015], Iss. 1, Art. 1 Figure 2. Composite SEBT Scores Following Treatment Composite SEBT Scores Following Treatment Mean Scores US Stretch Combo Pre Post 14

COMPARING THE EFFECTS OF DIATHERMY AND DYNAMIC STRETCHING ON HIP FLEXOR FLEXIBILITY AND POSTURAL CONTROL

University of Montana ScholarWorks at University of Montana Undergraduate Theses and Professional Papers 2015 COMPARING THE EFFECTS OF DIATHERMY AND DYNAMIC STRETCHING ON HIP FLEXOR FLEXIBILITY AND POSTURAL