Participants:
41 male fast and medium-fast pace bowlers out of which 36 players were Right arm and 5 were left-arm bowlers (having different Age (20.56 ± 4.13); Body Mass (65.62 ± 11.96); Height (1.69 ± 0.07); BMI (22.98 ± 3.34)) from various cricket academies from Amritsar, Punjab, India volunteered to participate in the study. Sample size was calculated with G power software (version 3.1). Sample size 33 was calculated at α error 0.05 with 80% power (1-β err prob). Participants included were asymptomatic and had no injuries, especially to the shoulder joint and back during 3 months before the testing.[11] 32 out of 41 participants had participated in at least state level tournament.
Surface:
Two distinct categories of surface namely natural bowling turf and concrete-based pitch were used to assess the bowling speed.
Different balls:
Two different types of balls were used in the study.
1) SG Club four-piece cricket leather ball (Red, weight- 156 gm) (Sanspareils Greenlandscricket) (Meerut, Uttar Pradesh, India)
2) Sixer hard tennis ball (Red, Weight- 120 gm) (Jalandhar, Punjab, India)
Four new balls (2 of each type mentioned above) were used in this study. [2]
Testing procedure
The study was approved by the institutional medical ethics committee of Guru Nanak Dev University, Amritsar, Punjab, India. Single occasion Cross-sectional design study, which included Physical profile evaluation and Bowling speed assessment, was performed. The bowling speed assessment was performed at various academies of Amritsar, Punjab, India. Physical profile evaluation included Body mass & Stature which was performed at strength analysis lab, Department of sports sciences and medicine, Guru Nanak Dev University, Amritsar. Statistical analysis and other research work were conducted at Human performance lab, Department of sports sciences and medicine, Guru Nanak Dev University, Amritsar. SRA 3000 Tracer Precision Radar gun (Homosassa, Florida, United States) with range up to 60 feet and measuring speed of 10-199 mph was used to assess the bowling speed of players.[12] Morning session (7 to 10 am) was selected for speed evaluation to avoid excessive exertion or fatigue for the bowlers as Amritsar is known for extremely hot weather in this season.
Participants were instructed to perform a warm-up of 15 minutes including running, stretching (static and dynamic stretches) & shadow deliveries.[11,13,14] Bowling facilities were pre-assessed for length, to confirm that each one is having a standard length of 20.12 m (22 yards). The edges of good length deliveries were marked with bowling cones at 3.8 to 5.8 m from Keeper’s end.
Participants were required to bowl 24 deliveries [(4 * 6 bowls per over); (2 overs on natural turf, 2 on cement surface* 2 different balls)]. The size of the facility enabled the participants to use their full run-up lengths. Participants were asked to bowl good length deliveries of maximum speed possible. Rest periods given between each delivery was 40-60s.[13] During deliveries front foot placement was monitored by assessor, so the “no-ball” deliveries get excluded as per the cricket bowling rules.[14] Within one over, half of the deliveries measured were at one end of the pitch (Bowling end) and a half at the other (Keeper’s end).[2] The order was consistent as Natural turf followed by Concrete-based surface.
At the bowling end, the gun was placed 5 m behind the bowling crease, pointing down a line joining the middle stump at the bowler’s end to the middle stump at the Keeper’s end.[13] At Keeper’s end, the gun was placed 3 m behind the middle stump, pointing towards the ball landed at good length from the middle stump.[2]A protective net was placed between a radar gun and stumps to prevent injury to the tester and radar gun.[3]
The procedure was repeated as two balls were included in the study. The sequence was maintained as bowling with SG season ball followed by Sixer hard tennis ball. Players were given adequate rest so they do not get fatigued. For this, each player was assessed for 2 days, 2 overs per day. Between each delivery 40-60 s rest was given and after each over 10-15 mins active rest was given.
Statistical analysis:
Measures of centrality and spread are presented as mean ± SD. The analysis was performed with all data included for 2 different surfaces. i.e. Natural turf and concrete-based pitch. Separately comparison between two ends of pitch and two different balls was performed.
Independent T-test was used to assess between-group differences. A level of p ≤0.05 was considered significant.[15] Statistical analysis was conducted using SPSS statistics version 23 (IBM, Chicago, IL, USA)