The Effect of Dynamic and Static Stretching on Golf Driving Performance (P2)
A total of 12 subjects (age: 22.5 ± 3.0 years; mass: 80.3 ± 6.4 kg; height: 1.84 ± 0.1 m), volunteered to take part in the experimental study. All subjects held a Council of National Golf Unions (CONGU) handicap of 5 or less (1.4 ± 1.9). Each subject regularly undertook fitness training programmes specific to golf, this made the individuals competent in performing the warm-up protocols to a high standard. Before testing took place, subjects were provided with a participation information form to read before the initial screening assessment.
Each subject was individually screened before participation with the use of a physical activity readiness questionnaire (PAR-Q). Informed written consent form was also obtained from each subject. Prior to commencing testing, approval for the study was obtained from the ethical committee of the School of Science and Sport, Institute for Clinical Exercise & Health Science, University of the West of Scotland, UK, Ethics Committee.
Each subject was required to attend two separate sessions on non-consecutive days. The testing lasted an average of two hours over a three / fve day period. All testing was performed at the same time of day to minimize the eﬀects of diurnal variation. Testing days varied slightly due to unpredictable weather conditions. Te testing between the DS and SS warm-up protocols were conducted in similar weather conditions. Wind, rain and temperature were taken into consideration; as these were the main factors that aﬀected ball deviation. Testing was canceled when the wind speed was ± 2 mph diﬀerent from previous testing sessions. A Kestrel 4500 anemometer (Champlain, NY, USA) was used to calculate weather conditions.
Prior to performance measurements being recorded on four diﬀerent aspects of golf driving, each subject was randomized to either a DS or SS routine on their first day of testing. Te opposite routine was then performed on the fnal testing session. Each testing session began with a 5 minute run at 40% of their perceived maximum running speed around the practice area. This was based on a study by Yamaguchi et al. (2007) who suggested the application of light aerobic exercises prior to warm-up . Te stretching protocols targeted the following parts of the body: the neck, shoulders, back, chest, hips, glutes, hamstring and thighs (Table 1). Te DS and SS were performed in the order displayed in table 1. Dynamic stretches were performed 15 times on both sides of the body or 15 times in 1 full body stretch over 3 repetitions, lasting for approximately 30 seconds due to the rate of stretch being 1 stretch every 2-second cycle.
The protocol used followed guidelines documented by . In the absence of any golf-specific, dynamic stretching protocols, and due to the rotational similarities between football and golf, we selected the dynamic stretching protocol of Alikhajeh et al., 2012 to be suitable in the present cohort of golfers . The instruction was given to move the body through as large a ROM as possible. One air golf swing was performed prior to testing. Each static stretch lasted for the duration of 30 seconds on each leg or arm before changing immediately to the contralateral side. Each stretch was completed 3 times. Participants were encouraged to stretch until they approached the end of the ROM but within the pain threshold. A 20-second rest between each body part stretched was facilitated.
Golf performance tests
Prior to testing, a large practice area with driving bays at Hamilton golf club (Hamilton, Lanarkshire, Scotland, UK) was set up with the appropriate equipment. Te practice area was situated on a slight slope with closely cut grass. Before testing began one particular driving bay was identified for the full testing process, this enabled a consistency
of the golfers positioning throughout the testing period. Four target poles were placed in the hitting area, to enable subjects to have a predetermined target. On both days of testing, subjects were required to bring their personal golf equipment with them. All golf shots were hit with relatively new Titleist PTs solo golf balls (Fairhaven, MA, USA).
No limitations were set for the driver the subjects used, however, the make and model of the driver had to be identical on both testing days. Afer the stretching exercises were completed each subject rested for 2 minutes before the hitting ten drives, with the distance, accuracy and ball contact being recorded from each shot. Subjects were encouraged to perform their personally devised pre-shot routine before every ball was struck. This allowed the subjects to mimic their tournament pre-shot routine. Moran et al. (2009) suggests this approach has the potential to make the results more consistent . Subjects were also instructed to strike the ball as hard as possible but with the aim of keeping control of the distance and accuracy of each golf shot. Ten drives were hit with a 1-minute rest between each shot; this was specified so that the participants could regenerate the metabolic energy that had been used in the previous shot.
A collection of data was taken from each subject with the use of a Silverline metric measuring wheel (Somerset, England, UK). This was sourced to calculate distance and accuracy with respect to the ﬂags placed on the midline of the fairway. The markings on the fairway ranged from 150-300 yards (Figure 1). Accuracy was measured by the absolute distance each shot deviated, left or right, from the predetermined target line. Measurement recordings were taken from the teeing area to the final resting position of the ball. To collect the contact data for each drive the subjects were asked “How well did you hit that one?” and they responded either with “yes” for good contact or “no” for poor contact. This simple approach was used by Gergley and colleagues and is considered an appropriate mode of assessment when working with golfers with a high skill level . Each individual subject was required to hit ten golf shots with a driver. This enabled calculation of the mean and standard deviation of each component of the ten drives. Driving performance indicators were also derived from the distance and shot accuracy measurements with respect to the dynamic and static stretch protocols. Distance index was expressed as a ratio of the driving distance after dynamic stretch to the driving distance after static stretch. Shot accuracy index was expressed as a ratio of the shot accuracy following dynamic stretch to the shot accuracy following static stretch protocols. Both the distance and shot indices were evaluated based on the outcome measure “symmetry” i.e. the closer the indices to 1 the more symmetric the performance. Te shot accuracy distance index was defined as the ratio of the shot accuracy to the driving distance. The lowers the shot accuracy distance index value the stronger the performance. This index was also applied after dynamic and static stretches.