Open and Closed Chained Activity Effect on Shoulder External Rotation Range of Motion using Whole Body Vibration Therapy Timothy L. Cooley, MS, ATC University of Utah Craig L. Switzler, MS, ATC University of Utah Bradley T. Hayes, PhD, ATC, LAT Assistant Professor Department of Exercise and Sport Science University of Utah Charlie A. Hicks-Little, PhD, ATC, LAT Assistant Professor Department of Exercise and Sport Science University of Utah ABSTRACT Manufacturers of vibration plates claim that vibration therapy is a whole body treatmentwhich has the ability to increase strength, balance, muscle endurance and flexibility; however, limited evidence is available to either confirm or refute this claim. The purpose of this study was to investigate the effects of vibration plate therapy on shoulder external range of motion (ROM) after an open kinetic chain (OKC) activity compared to a closed kinetic chain (CKC) activity. Twenty healthy subjects with no prior history of shoulder injury or surgery volunteered to participate in the study. Shoulder external ROM was measured before and immediately after each intervention session. The three interventions consisted of a control trial (no vibration therapy), standing trial (feet on vibration plate, OKC), and plank trial (hands on vibration plate, CKC). Data was analyzed using a repeated measure ANOVA. No statistically significant differences were found for shoulder external ROM for intervention by time (p>.05), or between genders (p>.05). However, a 3 increase in ROM was evident for both the OKC and CKC interventions which may suggest a clinically significant increase in ROM. In conclusion our findings indicate that a whole body effect is received during an OKC environment on the vibration plate. INTRODUCTION Manufacturers of vibration plates suggest that vibration plate therapy is a "whole body" treatment with the ability to increase strength, balance, muscle endurance and flexibility (Guffey, 2009). The focus of this paper was on flexibility and the influence open and closed kinetic chain whole body vibration plate therapy has on range of motion (ROM). ROM is the full movement potential of a joint and requires flexibility of the tissues surrounding the joint to allow for full Volume 1 Number 2 September 2013 Journal of Athletic Medicine Page 104
ROM. The literature currently reports increases in flexibility with soft tissue structures that are either directly in contact with the vibration plate or in a closed kinetic position with the vibration plate (Sands, McNeal, Stone, Russell, Jemni, 2006; Atha, Wheatley, 1976; Issurin, Libermann, Tenenbaum, 1994). However, there is a paucity of information in the literature that addresses the "whole body" physical adaptations with whole body vibration (WBV) treatment. The question remains as to whether a whole body effect can be achieved with vibration plate therapy or if it only affects those structures in contact with the plate. Closed kinetic chain (CKC) movements consist of those movements where the distal end of the limb is in a weight bearing position.[5] Examples of these types of movements include standing for the lower extremity or a plank position for the upper extremity. Open kinetic chain (OKC) movements include standing for the upper extremity or kicking (kicking leg), where the distal end of the extremity is not in contact with the ground or some other surface (Prentice, 2004). The purpose of this study was to determine if the effects of vibration plate therapy are "whole body", OKC, or only localized to those muscles that are in a CKC position with the vibration plate. Previous research has shown statistically significant increases in ROM, specifically in hamstring flexibility. These studies (Sands, McNeal, Stone, Russell, Jemni, 2006; Atha, Wheatley, 1976; Issurin, Libermann, Tenenbaum, 1994); however, only investigated protocols with the subjects standing in a static position on the platform, in a closed kinetic chain position. After extensive literature searches the authors were unable to find any previous studies on the effects of vibration plate therapy on ROM as it relates to open and close kinetic chain activities or the upper extremity, therefore leading to the present investigation. We hypothesized that external rotation shoulder ROM would increase in a healthy population after both the open and closed kinetic chain positions on the vibration plate (see figures 1a and 1b), but the increases in ROM would be similar between the two positions (Control<OKC=CKC). Whole body vibration therapy claims to increase flexibility in normal individuals and therefore a healthy population was chosen to be included as the study population in this research. METHODS Procedures and Findings Twenty (10 male and 10 female), age 23.10 ± 3.68 years, height 171.24 ± 9.80 cm, weight 71.85 ± 10.93 kg, BMI 24.1 ± 3.06 kg/m 2, healthy subjects volunteered for participation in the study. Subjects were excluded if they had a past history or current symptoms of shoulder discomfort, pain, abnormal ROM, as determined by a verbal report, or previous shoulder surgery. This exclusion criterion was selected to ensure all subjects would be able to perform the treatment positions in the study. All subjects completed an informed consent form approved but the University Institutional Review Board. All subjects performed three randomized treatment sessions; testing order was randomized by way of Latin Square. The treatments included the control, standing (upper body open chain) position and plank (upper body close chain) position. The control trial consisted of an initial shoulder external rotation ROM measurement followed by the same external rotation ROM measurement four minutes later. The four minute time period was selected as this was the time it took to perform all WBV treatments. The standing position consisted of the subject standing on the vibration plate with arms unsupported (Figure 1a). The plank position consisted Volume 1 Number 2 September 2013 Journal of Athletic Medicine Page 105
of the subject in the up part of a push-up position with hands shoulder width apart on the vibration plate and feet stationary on the ground (Figure 1b). Both positions were held static throughout the WBV therapy session. As per literature and manufacturer suggested treatment, the WBV (Vforce, Dynatronics, Salt Lake City, Utah) treatment lasted four minutes (30 seconds on followed by 30 seconds of rest) (Guffey, 2009). The frequency was set at 30 Hz and amplitude was set to low (Guffey, 2009). Figure 1a: Standing (OKC) position on Vibration Plate. Volume 1 Number 2 September 2013 Journal of Athletic Medicine Page 106
Figure 1b: Plank (CKC) position on Vibration Plate. External rotation measurements were taken in degrees of the dominant shoulder while in a supine position (Awan, Smith, Boon, (2002). All measurements were recorded before and after the treatment with an electric goniometer (PRO 360 Digital Protractor [± 0.1 ]) by the same examiner who was blinded to condition. The goniometer was attached to the medial side of the forearm along the ulna with the use of Velcro. The first strip of Velcro was placed around the wrist touching the styloid process of the ulna. The second strip was placed around the forearm in correspondence with the Velcro on the goniometer. The goniometer was then secured around the arm with Velcro strips (Figures 2a-c). Goniometer positioning and testing was performed by the same examiner to ensure consistency and reliability of measures (r =.88). External rotation was measured in accordance with Evaluation of Orthopedic and Athletic Injuries (Starkey, Ryan 2002). The end passive ROM measurement was taken once the patient felt discomfort. A predetermined verbal cue was established between subject and examiner prior to testing to inform the examiner when to stop. The verbal cue was used once the patient felt slight discomfort. The subject was instructed to remember the level of discomfort and try to equal that amount for every measurement. Volume 1 Number 2 September 2013 Journal of Athletic Medicine Page 107
Figure 2a-c: Illustration of External Rotation ROM measurements; a) starting position, b) placement of electric goniometer and, c) end position of measurement. Testing with each subject occurred over a period of one week with a minimum of 23 hours and no more than 48 hours between each session. The mean of 3 measures were recorded into our data set and used in a 2 x 3 repeated measures ANOVA analysis. The level of probability was set at P 0.05 for all statistical tests. RESULTS a b c All subjects completed all three testing sessions. Table 1 reveals subject shoulder external rotation range of motion values pre and post each treatment session. No statistically significant differences were found for shoulder external ROM for intervention by time (p>.05). However, a modest 3 increase in external rotation ROM was recorded for both the OKC and CKC interventions. Table 1: Subject External Rotation Range of Motion measures Pre and Post by Condition (N=20). Condition Pre (Mean ± SD) Post (Mean ± SD) Control ER ROM ( ) 128.15 ± 17.37 128.35 ± 19.80 Plank ER ROM ( ) 129.76 ± 17.65 132.83 ± 18.45 Standing ER ROM ( ) 130.69 ± 16.55 133.77 ± 18.55 DISCUSSION The purpose of this study was to determine if the effects of vibration plate therapy are "whole body", OKC, or only localized to those muscles that are in a CKC position with the vibration plate. However, neither OKC nor CKC activity provided statistically significant ROM increases. Figures 3 and 4 demonstrate an increase in shoulder ROM from pre to post test by 3 Volume 1 Number 2 September 2013 Journal of Athletic Medicine Page 108
degrees in both the OKC and CKC position. It is surmised that this modest increase may have a clinically relevant role for clinical healthcare professionals trying to improve ROM, however it must again be noted that this increase in ROM did not meet statistical significance. Figure 3: External Rotation ROM measures pre and post WBV treatments Figure 4: Line graph reflecting changes in ROM post WBV treatment. Currently the research is limited in the area of whole body vibration therapy. There are many theories as to how the vibration therapy may work to increase shoulder ROM; however, it Volume 1 Number 2 September 2013 Journal of Athletic Medicine Page 109
is still relatively unclear. Some of the limitations to this current study may fall under the following assumptions. During a hamstring CKC activity the muscle fibers are in line with the direction of vibration. In our study the plank position resulted in a perpendicular orientation of the fibers to the vibration of the platform. Another issue with fiber direction is use of the muscles. By nature we stand on a regular basis and therefore it is possible that the muscles are custom to that direction of force application. A plank position is not a "normal" daily activity for most people. Even those that partake in the activity don't perform the activity as often as they would stand or walk. This would suggest that holding the plank position might have decreased the possible ROM gains due to the isometric use of the shoulder muscles and a muscle guarding or fatigue effect may have occurred. Therefore, two recommended changes for better outcomes in the future might be to increase the sample size as well as change the orientation of the CKC position of the shoulder to be more parallel to the vibration plate forces. Finally, a further limitation that must be noted regarding this study was that a healthy population with normal ROM was utilized as the study population and therefore only small increases in ROM were possible from the start. However, although there were no statistically significant increases in ROM revealed in this study there was a small increase in ROM present after both the OKC and CKC therapy sessions which provides insight into the potential impact WBV could have on increasing ROM in a patient population with restricted ROM. This increase in shoulder ROM with the use of vibration plate therapy warrants further research in this area to determine whether this modality may potentially be a useful tool in the rehabilitation process, especially in a pathological patient. With the information presented in this study OKC activities and the use of vibration plate therapy could be incorporated into current clinical rehabilitation plans as an adjunct tool. Examples of possible use could be for ankle rehabilitation where the patient stands on the uninvolved limb and suspends their injured limb. Another example would be similar to this study but for post-shoulder surgery ROM increase, where small increases are preferred in the early stages of rehabilitation. CONCLUSION In summary, the results of this study revealed that neither an OKC nor a CKC activity on the vibration plate resulted in a statistically significant increase in shoulder external rotation ROM. However, the results do suggest a practical application of vibration plate therapy to increase shoulder external rotation flexibility in the clinical setting due to the 3 increase in ROM evident after both the OKC and CKC vibration plate therapy sessions. This finding indicates that a whole body effect is received during an OKC environment on the vibration plate. The small increase in shoulder external rotation ROM evident in this study warrants further investigative research into the effectiveness of vibration plate therapy in increasing whole body muscular tissue mobility. REFERENCES Atha, J., Wheatley, D.W. (1976). Joint Mobility Changes Due to Low Frequency Vibration and Stretching Exercise. British Journal of Sports Medicine. 10, 26-34. Awan R. Smith, J, & Boon A.J. (2002, September). Measuring Shoulder Internal Rotation Range Volume 1 Number 2 September 2013 Journal of Athletic Medicine Page 110
of Motion a Comparison of 3 Techniques. Archives of Physical Medicine and Rehabilitation. 38 (9), 1229-1234. Guffey, J. Stephen. (2009) Vibration Therapy: Application's Manual. Issurin, V.B., Libermann, D.G., Tenenbaum, G. (1994) Effect of Vibratory Stimulation Training on Maximal Force and Flexibility. Journal of Sports Science. 12 (6), 561-6. Prentice, W. (2004). Rehabilitation Techniques for Sports Medicine and Athletic Training. (p. 12) (4th ed.) New York, NY: McGraw-Hill Companies. Sands, W.A., McNeal, J.R., Stone, M.H., Russell, E.M., Jemni, M. (2006). Flexibility Enhancement with Vibration: Acute and Long-Term. Medicine & Science in Sports & Exercise. 38 (4), 720-5. Starkey, C. & Ryan J. (2002). Evaluation of Orthopedic and Athletic Injuries. (pp.444-5) (2 nd ed.) Philadelphia, PA: F.A Davis Company. Volume 1 Number 2 September 2013 Journal of Athletic Medicine Page 111