Effects of percussion massage therapy,dynamic stretching,and static stretching on physical performance and balance

2.1 Study design

This study is a single-blind randomized trial. The design was set up as 3 separate interventions: Dynamic stretching group; static stretching group and percussive massage therapy group. Demographic information, horizontal jumping test, T drill test and balance measurements on a single leg with open and closed eyes of all participants were recorded before the study. Individuals participating in the study were given numbers according to the order in which they were included in the study. Randomizer.org site was used to generate random numbers for the individuals listed in the order of selection. After 48 numbers were randomly divided into 3 groups, the numbers given to the participants determined the groups of the participants. The evaluators were aware of the study objectives and the allocation of participants in the study groups. The participants were blind the group to which they belonged. The sequence of randomization was hidden from the evaluators and the patients. The participants rested for 30 minutes to avoid fatigue after the first evaluation and were randomly divided into three groups. After the applications, all assessments were performed again.

2.2 Participants

The study was conducted with forty-eight healthy individuals who were at Istanbul Medipol University in Istanbul. All participants were recruited between January and March 2022. This study was performed by the Declaration of Helsinki regarding the ethical principles for medical research involving human subjects. The study protocol was approved by the Non-interventional Ethics of Istanbul Medipol University (Number: E-10840098-772.02-6484). The protocol of the study was registered at ClinicalTrials.gov (NCT05192070). The participants who were 18–25 years of age, able to perform performance tests, did not have any orthopedic surgery, did not have problems during running and sudden turning, and did not have a professional sports history were included in the study. The exclusion criteria were defined as a history of trauma, anatomic deformities such as pes planus or pes cavus and skeletal system fractures, being included in a physiotherapy program in the last 6 months and having orthopedics or rheumatologic diseases.

Two of the fifty-two patients included in the study were excluded because they did not meet the inclusion criteria and two refused to participate in the study. Forty-eight individuals were divided into three groups by the randomization method. A detailed study flowchart was shown in the consolidated standards of reporting trials flow diagram (Fig. 1).

2.3 Intervention

2.4 Outcome measurements

2.5 Statistical analyses

SPSS (Statistical Package for Social Sciences) 22 version program (SPSS, Inc, Chicago, IL) was used in the data analysis of the study. The Kolmogorov-Smirnov test was used to assess the normality. Data was revealed to be normally distributed ( $p>$ 0.05) and equal variances were assumed ( $p>$ 0.05). The mean ± one standard deviation (SD) was computed for all variables. Intra-group and intergroup analyses of data were performed with “One Way ANOVA”. Difference analysis between groups was performed with the post hoc test “Tukey HSD”. An alpha level of 0.05 was set for significance for the statistics.

Individuals were selected among those who were in the Istanbul Medipol University. Individuals were divided into 3 groups as dynamic stretching, static stretching and percussive massage therapy. Baseline characteristics of the participants were shown in Table 1.

The comparison of pre-post treatment evaluation parameters within the group is shown in Table 3. When the values of the pre and post-treatment of all groups in the study were compared, significant improvements were observed in the t-drill test, horizontal jumping test and right/left foot balance with eyes open in the dynamic stretching group ( 0.05). There were no significant changes between pre and post-treatment values in the static stretching group ( $p>$ 0.05). Also, significant improvements were observed in all values in the percussive massage therapy group ( $p>$ 0.017, Table 3).

4.1 The effects of percussive massage therapy on physical performance and balance

There are many applications of percussion massage therapy of different duration and intensities in the literature. Many manufacturers have a variety of models with various settings that may include different speeds/frequencies (i.e., 17–53 Hz), amplitudes, and applicator tips (e.g., large and small ball, flat tip, bullet tip, fork. Device percussion settings are often within the range of frequencies and amplitudes (e.g., 5 to 300 Hz) found to produce positive myofascial outcomes. In most studies, Hypervolt devices moved 2 to 5 seconds along the body region (up and down) for pre-exercise. And 33–40 Hz is preferred for pre and post-exercise for medium speed [2]. In the present study, the Hypervolt device was applied to each muscle group for 3 minutes at an intensity of 40 Hz for medium speed.

Konrad et al. examined the effects of the Hypervolt percussive massage device on plantar flexor muscles’ range of motion and performance. No difference was found in maximal voluntary contraction performance after using the Hypervolt device compared to the control group [18]. Lin et al. indicated that the use of a vibration foam roller of 38 Hz on bilateral hamstrings in college students caused no significant improvement in the vertical jump [19]. Contrary to these studies, physical performance and single-leg balance results were improved with the application of 3 minutes of Hypervolt in each quadriceps, hamstring and gastrocnemius muscle in the present study. T-drill and horizontal jumping results were improved with percussive massage therapy.

A possible mechanism for these results might be that Hypervolt can stimulate more muscle receptors which lead to increased motor fiber recruitment [2]. We speculate that the following mechanism underlies the reduced muscle stiffness after Hypervolt: it may modulate myofascial tone through changes in thixotropic properties, blood flow, and fascial hydration, affecting tissue stiffness [9]. In addition to these effects, the transmission of additional mechanical oscillations to the target muscles affects several physiological systems, such as the Golgi tendon organ. One study showed that vibration therapy considerably improved muscle performance. They reported that there were significant increases in both knee flexion and extension range of motion and muscle strengths as well as dynamic balance after vibration therapy. Lee et al. demonstrated that vibration roller on hamstrings and quadriceps significantly increased the range of motion of knee flexion and extension, and isokinetic peak torque, muscle strength, and dynamic balance were also increased [3]. Another study reported that changes in balance behaviors within the eyes-closed condition were observed when vibratory stimulation was applied to the gastrocnemius muscle. The efficacy of vibration therapy applied to the gastrocnemius muscle at a frequency of 30 and 40 Hz was compared. It was observed that the vibration applied at 40 Hz was more effective on the center of gravity sway [20]. Similar to this, a present study showed that Hypervolt applied at a frequency of 40 Hz improved the balance of standing on one leg with eyes open and closed. Another study reported that vibration stimulation applied to the tibialis anterior and gastrocnemius improve balance when a person’s eyes are closed during double-leg standing [21]. Also, it has been established that somatosensory stimulation with vibration can decrease postural sway in normal subjects when their eyes are closed [22]. Present study results about balance are similar to them. We consider that stimulation of the afferent fiber of the muscle spindles with Hypervolt results in the maintenance of proper postural balance.

4.2 The effects of dynamic and static stretching on physical performance and balance

Several studies have shown that dynamic stretching improves power, sprinting, and jumping performance [23, 24]. For muscular performance, this stretch modality has been proven to be more effective than no-stretch and static stretching [11]. When compared to static stretching, it was found that dynamic stretching generated an equal or larger acute gain in flexibility [25]. On the other hand, others showed that static stretch was more efficient than dynamic stretch for ROM improvements. The viscoelastic stress relaxation that occurs when the muscle tissue is kept stretched in a fixed position during static stretching may be a factor in the difference in stretch-induced effects on flexibility [26]. Also, many studies reported that dynamic stretching has also been shown to be more efficient than no-stretch and static stretching in power, sprint and jump performance [23, 27]. According to our results, t-test and horizontal jumping test results were improved with dynamic stretching while no improvements were seen in physical performance and balance results with static stretching.

According to one study, the 15-second static stretching protocol significantly improved dynamic balance scores [28]. On the other hand, these findings differed from the findings of Brandenburg, who observed balance performance with a 15-second static stretching [29]. Handrakis et al. the effects of an acute static stretching protocol on balance and jump/hop performance in active middle-aged adults. They reported that 10 minutes of acute static stretching improves the dynamic balance of inactive middle-aged people while not affecting jump/hop performance [30]. This study’s findings were not consistent with our findings.

Earlier studies focused on the acute effect of dynamic stretching in facilitating physical performance such as power, sprint, agility, and jump performance through the effect of dynamic stretching on dynamic balance is limited to the best of our knowledge [31, 32]. One study reported that dynamic stretching also produced significant changes in dynamic balance performance [33]. In contrast, Azeem and Sharma found that the dynamic and static stretching exercises have the same effect on the dynamic balance performance [34]. On the other hand, Chatzopoulos et al. compared the effects of the static and dynamic stretching exercises on dynamic balance performance and found that the dynamic stretching exercises were more effective than static stretching [35]. In our study, only dynamic stretching was found to be effective in balance resulting in open eyes and closed. We consider that the reason for the improvement in the balance following dynamic stretching may be due to an increase in heart rate, increase in muscle temperature, enhancement of neural activation, and specific rehearsal of movement patterns possibly leading to increased proprioception.

4.3 Limitations

One of the limitations of the study was that it did not examine the long-term effects of the applied techniques. Also, individuals who do not participate in athletics made up the majority of those included in the study. Another limitation in our study, in which we included healthy people, was not evaluating whether people had difficulties in performance tests.