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Scapular Dyskinesis; Ballistic Stretching; Sleeper Stretching; Kibler’s LSST; Speed Gun.

Introduction

Cricket is played all over the world where high intensity overhead activities are more in Bowling and fielding than batting which involves Physical as well as mental health. Pacers are fast bowlers who have three type of bowling: side-on, Front-on and mixed and spinners are spin bowlers. Mixed type bowling is more problematic and leading high incidence of injuries in fast bowlers [1]. Bowling consists repetitive twisting extension and rotation which over time produce a gradual deterioration in functional capacity of body. Many studies shown that prevalence of Scapular dyskinesia are high in overhead athletes.

According to the standard classification, SD can be type I; a posterior displacement from posterior thorax of inferior medial angle, Type II; entire medial border of scapula and type III; an early scapular elevation or excessive/insufficient scapular upward rotation during dynamic observation.Flexibility is a prime fitness component which helps in performance, posture, movements, body alignment, muscle length, Balance and injury prevention. Stretching used for warm up before and after sports for recovery to prevent injuries and improve flexibility.

The sleeper stretch is performed with the patient lying on their injured side with the shoulder in 90° forward flexion, the scapula manually fixed into retraction, while glenohumeral internal rotation is performed passively [2]. The patient should feel a stretch in the posterior aspect of the shoulder and not in the anterior portion, if they do, then reducing the intensity and rotating the trunk slightly backward can reduce the intensity of the stretch. Ballistic stretching includes rapid, alternating movements or ‘bouncing’ at end-range of motion with repeated several times while gradually increasing the range of motion, so that the targeted tissues become gradually elongated. Muscles to be stretched are infraspinatus, teres minor, supraspinatus, and subscapularis. Static stretching involves moving the joint to the point in which there is considerable resistance from muscles tension [3]. The stretch is maintained at this point until reduction of tension takes place and then the joint is returned so far that the stretch is released. Static stretching may also be repeated several times.

Several studies have shown the alteration of scapular position and decreased flexibility in non- professional bowlers which can lead to sports related shoulder injuries and might affect the performance of athletes. The athlete has to pay a heavy price of delayed recovery, heavy cost of rehabilitation, inability to qualify for the match, ultimately his/ her career goes into toss. Separate studies done on various stretching techniques but there is lack of evidence.

Technique is more effective. The intervention being simple selfperformable by the athletes, and easily administrable under supervision of the therapist, can manifest promising results among the athletes and sports related to upper limb function. This can be a ground breaking intervention among the population of athletes suffering from altered scapular biomechanics if found effective. Therefore, the purpose of the study is to compare the acute effect of ballistic stretching and sleeper stretching in combination with static stretching to improve the flexibility, bowling speed in fast bowlers with scapular dyskinesis [4].

Method

Study design and participants: An Experimental-Comparative study was studied on 30 male subjects selected through Random sampling method with two groups of 15 in each group Fast bowlers aged between 19 years to 40 years from various colleges, cricket academy and clubs with scapular dyskinesis.

Procedure: Subject were instructed to lie-down in side lying position on couch or yoga mat as per their comfort. Therapist stood by the side of the subjects instructing them to abduct their shoulder joint at 90˚ and elbow bent at 90˚.

Group A: Ballistic stretching

The therapist slightly pulls the shoulder joint at end range of external rotation. Then the subject was instructed to perform jerky movement as fast as possible from the end range of external rotation till end range of internal rotation of the shoulder joint. This action was repeated continuously for 15 repetitions per 2 sets for 1 week.

Group B: Sleeper stretching

The subject was instructed to grab the wrist of their dominant side arm with the help of non- dominant hand and slowly push the wrists in the direction of Internal Rotation as far down as until feeling that the shoulder tissue was being pulled without any pain. Then the position was held for 30 sec and repeated 5 times for 1 week.

Static stretching for both group

Subject were instructed to sit or stand as per their comfort. Then the subject was asked to bring their shoulder up toward their ears until a strong stretch sensation was felt in extensor muscles of shoulder joint [5]. Then to perform the unilateral shoulder abductor stretch, subjects were instructed to sit or stand then subjects were asked to bring their arm across the chest as close as possible using help of non-dominant hand. Subjects were asked to repeat 3 times with each repetition lasting for 30 seconds for 1 week.

Outcome measures

All the subjects were evaluated for outcome measurement before and after one week of intervention: the measurement was measured for Scapular dyskinesis using Kibler’s Lateral Scapular Test (KLSST), shoulder flexibility by using Apley’s Back Scratch Test for and bowling speed by Bushnell Radar Gun. Independent variables were Ballistic stretching, sleeper stretching and static stretching whereas Dependent Variables were scapular Dyskinesia, shoulder flexibility and bowing speed [6].

Statistical Analysis

Statistical Methods:

The data had collected on base line characteristics and outcome measures data of Kibler’s Lateral Scapular Slide Test (LSST), Apley’s back scratch test, bowling speed was analysed by SPSS software through using following statistical techniques.

Frequency and percentage analysis, Chi-square test was used to describe the age and gender distribution of the subjects, Apley’s back scratch test for categorical data.

Mean and SD was used to assess the pre and post-test outcome measures of the subjects in both the groups.

Paired ‘t’ test as a parametric was used to analysis the variables pre-test to post-test with calculation of percentage of change.

Independent ‘t’ test as a parametric was used to compare the means of variables between groups with calculation of percentage of difference between the means.

Results and interpretation

Group A had 15 male subjects with mean age 21.33 years and Group B there were 15 subjects with mean age 21.87 years were included in the study. There is no significant difference in mean ages between the groups. There was no female subject were included in the study [7].

Both Group A and Group B had shown statistically significant change in means of Kibler’s Lateral Scapular Slide Test (LSST) measured at o° and 45° and bowling speed but no significance difference LSST at 90° when means were analysed from pre-test to post-test within the group A and group B with p<0.000 respectively.Pre intervention means and post intervention means were compared between Group A and Group B there is no statistically significant difference in means of bowling speed. When post-test means of Apley’s back scratch test score within Group A and Group B found that the higher percentage of score found under excellent category of test measurement. Between the group comparisons the improvement in score from poor to excellent is found in the both groups.

Discussion

Study was conducted to find out the acute effects of ballistic and sleeper stretch in scapular dyskinesis, bowling speed and shoulder flexibility among elite fast bowlers. In this study it was found that within the group comparison between Ballistic stretching and Sleeper Stretching in Group A and Group B respectively, were equally effective in manifesting improvement in scapular dyskinesis, bowling speed and flexibility when compared from the baseline to post intervention test. Whereas comparison between the groups didn’t have statistically significant difference in scapular dyskinesis, bowling speed and flexibility.

In Group A (Ballistic stretching), analysis of scapular dyskinesis, bowling speed and flexibility of shoulder joint within the group in which ballistic stretching was performed showed statistically significant improvement in means of KLSST test measured at 0˚, 45˚, bowling speed and flexibility but no significance difference KLSST at 90˚ when means were analyzed from pre intervention to post intervention within the group. M kaya et al., conducted a study where they recommend using the ballistic stretching technique to achieve greater and longer lasting increase in tendon length and rage of motion.65 Similarly Wolstenholme MT et al., in his study only the ballistic stretching group had demonstrated an acute increase in muscle flexibility. Ballistic stretching consist of quick muscles contraction [8-12]. These are a series of eccentric contractions followed by concentric contraction of muscles. It is understood that if a muscle is stretched immediately before it is shortened concentrically, then the force generated is greater than a concentric contraction alone. This is due to the energy stored in the muscles and tendons. Konrad et al., in his study of ballistic stretching training effects on muscle and tendon concluded that altered tolerance to stretching seems to be a plausible explanation for the gain inflexibility.

In Group B (Sleeper stretching), analysis of scapular dyskinesis, bowling speed and flexibility of shoulder joint within the group in which ballistic stretching was performed showed statistically significant improvement in means of KLSST test measured at 0˚, 45˚, 90˚, bowling speed and flexibility when means were analyzed from pre intervention to post intervention within the group. It is proposed that the muscle spindle records the change in length and sends signals to the spinal cord which convey the stretch information which triggers the stretch reflex. This change in muscle length by causing stretched muscle to contract.66A possible explanation for the greater increase in flexibility after the static exercise may be the viscoelastic stress relaxation that occurs when the muscle tissue is kept stretched in a fixed position.

There is no statistically significant difference found in means of Kibler’s Lateral Scapular Slide Test for SD, bowling speed and Apley’s Back Scratch test for shoulder flexibility when compared in-between the Ballistic Group and Sleeper Stretching Group, that suggest both groups intervention were equally effective.

Analysis shows that Ballistic Group and Sleeper Group respectively have shown statistically significant improvement in Scapular Dyskinesis, Speed of bowling and Shoulder flexibility.

Hence the present study accepts the null hypothesis. As there is no statistically significant difference in means between the groups.

Future Recommendations

1. Both male and females subjects can be included in the study.

2. Long term effect of the intervention can be studied.

3. Interventions addressing both the factor leading to biomechanical misalignment

4. Compliance with Ethical Standards:

Ethical approval: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with declaration and its later amendments .

1. Khalil M, Teunissen CE, Otto M, Piehl F, Sormani MP, et al. (2018) . Nat Rev Neurol 14:577-589.
2. Schlaepfer W, Lynch R (1977) . J Cell Biol 1:74:241-250.
3. Kuhle J, Barro C, Andreasson U, Derfuss T, Lindberg R, et al. (2016) . Clin Chem Lab Med. 1:54:1655-1661.
4. Gaiottino J, Norgren N, Dobson R, Topping J, Nissim A, et al. (2013) . PloS One.8:e75091.
5. Disanto G, Barro C, Benkert P, Naegelin Y, Schädelin S, et al. (2017) : Serum NfL as a Biomarker in   MS. Ann Neurol. 81:857-870.
6. Barro C, Benkert P, Disanto G, Tsagkas C, Amann M, et al. (2018) . Brain J Neurol. 1:141:2382-2391.
7. Cantó E, Barro C, Zhao C, Caillier SJ, Michalak Z, et al. (2019) . JAMA Neurol 76:1359-1366.
8. Novakova L, Zetterberg H, Sundström P, Axelsson M, Khademi M, et al. (2017) . Neurol. 89:2230-2237.
9. Jakimovski D, Kuhle J, Ramanathan M, Barro C, Tomic D, et al. (2019) . Ann Clin Transl Neurol. 6:1757-1770.
10. Siller N, Kuhle J, Muthuraman M, Barro C, Uphaus T, et al. (2019) . Mult Scler Houndmills Basingstoke Engl. 25:678-686.
11. Delcoigne B, Manouchehrinia A, Barro C, Benkert P, Michalak Z, et al. (2020) . Neurology. Mar 17:94: e1201-1212.
12. Piehl F, Kockum I, Khademi M, Blennow K, Lycke J, et al. (2018) . Mult Scler Houndmills Basingstoke Engl. 24:1046-1054.