Biofeedback training sessions

Putt result data were provided to all participants within two weeks of data

collection. This included the mean putt result for both the 4m and 8m putts, and a ranking between 1 and 38 within the sample for putting performance. At this time volunteers were called to participate in a follow up biofeedback study that would

last four weeks, with week 4 being a retesting session on the putting green. Twelve participants agreed to take part in the biofeedback training study.

The following week, ten participants completed the first training session. The second and third week, nine participants completed the training sessions. In week four, seven participants completed the retesting on the putting green. The data from these seven participants were used in all analysis of the biofeedback group.

Biofeedback training was completed in the committee room of the golf club. This was a room measuring 6m x 4m, with a white wall suitable for projecting the image from the pliance® software out of the laptop via a video projector. Each participant completed the training immediately prior to the completion of their round of golf on three consecutive Wednesdays. No participant was required to change their normal routine in order to complete the training sessions.

The apparatus used in the biofeedback training sessions included: • Pliance® mat used in data collection (Figure 5.3.1a)

• Pliance® X data collection box (Figure 5.3.1b) • Panasonic video projector

Figure 5.3.1a & b: (a) Pliance® mat system, and (b) the updated pliance® X analyzer box used during biofeedback training.

The software used for these training sessions was novel pliance® 10.2.22. The pliance® X box is an updated version on of the data collection unit used during data collection with a higher hardwired sample rate (20,000 sensor samples per second). This combination of apparatus allowed the real-time projection of the pliance® information directly onto the wall facing the participants as each stood on the pliance® mat. The pliance® 10.2.22 software allows the mat to be divided into left and right sides in real time. This can then be displayed in real time. This feature is not available in the pliance® 8.3-C software, however the pliance® X hardware was not available when the pliance® mat was being validated against the AMTI plate, so was not used during data collection.

The real time display is depicted in figure 5.2.2. A number of options were

possible. Initially the participants were introduced to the concept of understanding the signal output as suggested by Cattaneo and Cardini (2001) via the display of real-time 2D pressure pictures as depicted in the left hand side of Figure 5.3.2.

in the orientation provided to the participant. The information on the right side of the screen represents peak pressure, force and area v time curves. These curves were not referred to or used during the biofeedback sessions. Small images on the extreme right of these figures represent recently opened or stored data files. This information was also ignored during the biofeedback sessions.

Figure 5.3.2: Print screen capture of pressure information as viewed by each participant in the biofeedback training group. Left hand side of the image provides a 2D representation of the left and right foot (heel at bottom of the image). The circled dot in

the middle of the picture is the location of the COP.

In the first week of the biofeedback training program participants were shown how to interpret the pictures by firstly placing one foot on the mat whilst watching the screen, then the other foot. Whilst this was happening, the researcher was pointing out the relevant images of the outline of the feet, the position of the COP (the blue dot with white and black border around it), and how the position of this COP is influenced by movement and weight distribution (see Figure 5.3.3). All participants were asked to ignore the right hand side of the screen at this stage of training.

Figure 5.3.3: Print screen capture of pressure information as viewed by each participant in the biofeedback training group when only the right foot is placed on the mat.

Subsequently, participants spent 5-10 minutes becoming familiar with the mat and the display. During this time all participants were fully clothed and wearing standard street shoes or golf shoes. Following this familiarization process, the participants were asked to step off the mat, the mat was zeroed, then they stepped back on and were asked to concentrate on keeping the COP as still as possible by concentrating on it’s position on the screen. The protocol used for each participant included one minute of focus on the COP, one minute of eyes closed and trying to stay as balanced as possible, another minute of focus on the COP, another minute of eyes closed, and one final minute of focus on the COP. At the end of this time, the researcher asked the participant if they felt

comfortable with their eyes closed, and whether they could feel a difference between the eyes open and closed conditions. This was to orient them to the feeling of being relatively stable. They were then asked to step off the mat.

Using the pliance® 10.2.22 software, the left and right sides of the mat were then masked (a term used by novel to indicate the breaking down of an area into smaller parts) so that the information pertaining to the left and right foot could be displayed as individual columns (or bars) on the screen. A balanced, symmetrical position (Nichols, 1997) was explained to each participant as keeping each of the two columns on the far right of the screen at the same height (Figure 5.3.4). If the load under the foot was more centred on one side, for example the left side, then the COP and bar heights would represent this asymmetrical loading (Figure 5.4.5). The same procedure of alternating one minute with eyes open, one minute with eyes closed protocol was completed. On completion of this exercise the participant was free to leave. The session took approximately 15 minutes to complete.

Figure 5.3.4: Print screen capture of pressure information as viewed by each participant in the biofeedback training group where the load under each foot is presented in column form on the extreme right hand side of the image. This image indicates relatively equal

Figure 5.3.5: Print screen capture of pressure information as viewed by each participant in the biofeedback training group where the load under each foot is presented in column form on the right hand side of the image. This image indicates a greater load on the left

foot.

Using the same equipment set up described for week 1 above, the week 2

biofeedback training session started with each participant repeating the exercises completed in week 1 (alternating minutes of eyes open, eyes closed with 2D representation of the feet, then columns). Whilst standing on the pliance® mat each participant was then asked to mimic their putting address position. Once comfortable they were then asked to look at the screen to note the position (and stability) of the COP location (using the 2D representation).

When each participant was able to maintain the COP in a relatively stable position, they were then asked to make a “phantom” putting movement whilst looking at the screen. This was to highlight to them how their COP moved when they made the putting stroke. The researcher then explained to each participant that Pelz (2000) putting theory includes the ability to maintain balance during the putting stroke by focusing on movement of the shoulders rotating about the trunk

in a vertical fashion (keeping the triangle shaped depicted in Figure 2.1), as opposed to movement of the arms on a fixed trunk. The participant was then encouraged to repeat the phantom putting procedure and focus on developing a feel for the putting motion that kept the COP in the most stable position. All participants agreed that the shoulder putting method was the most suitable for this. At the completion of this set of exercises the participant was free to go, but they were encouraged to emulate what they had “felt” in their round of golf.

Each participant was asked to bring their putter with them for the week 3 training session. The exercises alternating eyes open, eyes closed were completed initially. Then holding the putter as per normal, and standing in their putting address position, each participant watched the screen to determine the location and stability of the COP. Then making their standard putting stroke (apart from looking up at the screen), participants observed the movement (or lack of movement) of their COP. These participants were reminded of the need to putt with their shoulders and arms moving as one unit about their trunk. All

participants spent 3-5 minutes performing this task, using the feedback from the 2D COP location projected onto the screen. After this exercise was completed, participants were free to leave, but were asked to emulate the feeling of the putting stroke they had just achieved in their round of golf.

The following week, seven players were re-tested using the same procedures outlined in section 5.2.

6 Data analysis – pre intervention testing

This chapter presents data on the putting performance measures of this sample of players on each of the two putting tasks (n=190). Each putt is treated

separately. Putts that successfully achieved a “holed out” result were removed from some parts of this analysis. Where removal from the sample is the most logical way of treating these putts, this is pointed out to the reader.

It was not assumed in the analysis of putting performance that holed out putts would have traveled past the hole. It is possible for the ball to drop into the hole; that is, distance past the hole = 0cm. However, as the velocity of the ball when it dropped into the hole was not measured, holed out putts are treated separately to putts that finished past the hole.