Human Performance - Discussion

The evaluation process was conducted with the intention of increasing the range of information and understanding of the performance structure that affects the world of the athletes from the DPS team. It also aimed to analyse and compare individual results, contrasting them with other team members and to eventually relate these to other Paralympic athletes (e.g. wheelchair sports).

This athlete, born in June 1984, has a training history of nearly 10 years with the DPS team.

He participated in the Winter Paralympic Games in Vancouver, performing well but did not win any medals. He was exemplary in his performance of the experiments developed over the two evaluative campaigns of this study and presented interesting and respectable results for this competitive sport, as well as for the scientific community.

Anthropometric Assessment

From the anthropometric measurements taken, it was observed that the volunteer reduced his body weight from 62kg to 59.5kg during the period between the two evaluative campaigns. As a consequence, this altered his body mass index with it reducing to 23.24kg/m², however, remaining within the range considered as normal according to “The Practical Guide: Identification, Evaluation, and Treatment of Overweight and Obesity in Adults” (National Institutes of Health, 2000).

Data collected during the 2^nd campaign included measurement and recording of the seated height (116cm) and arm-span (177.5cm) of C1. From this information it was possible to determine his trunk index (Cormic Index, the ratio between the seated height and total height; Relative Arm-span,

arm-span in relation to height). C1 presented the highest Cormic Index (72.5) of all those athletes taking part in the 2^nd campaign, and it can be said that C1 has an advantageous trunk height and larger relative arm-span (110.93) in terms of his total height. In relation to the sport of Alpine Skiing, this presents a disadvantage from an aerodynamics perspective given that his frontal area is subject to wind exposure whilst skiing, and an advantage from a motor point of view as his arms have greater reach, thus affecting his directional ability and maintenance of equilibrium.

Physiological Assessment

These anthropometric characteristics can be considered advantageous for pre-season fitness preparations in terms of physiology. Having a larger trunk size and relative arm-span can enable an athlete to increase the muscle mass of the trunk and upper limbs and improve aerobic fitness, having a positive effect on metabolism and reducing complications caused by the spinal cord injury (Bhambhani, 2003). The spiroergometry evaluation carried out to check the fitness condition of this athlete produced consistent and coherent results without exposing him to risk. This present study was also able to take into account and to use as a benchmark for comparison of performance evolution, previous results presented by C1 in 2004. It can be said that C1 has reached a plateau, having presented very similar performances in 2010 and 2011, with testing on both occasions ending at the same stage and within the same time duration, and in addition presenting virtually the same HRmax. When comparing the 2 readings of C1, they were lower in the 2011 evaluation when compared to both 2004 and 2010, although, he was able to continue the test for a longer time period in 2010 and 2011. The 2 values presented by C1 were 2137ml/min (34.46 ml/kg/min) in the 1^st campaign and 1958ml/min (32.90 ml/kg/min) in the 2^nd campaign. Although this test protocol differs from those adopted by other authors in their evaluations, as detailed by (Bhambhani, 2002) in Table 4, the results are comparable with them. It should be noted that the results encountered in Table 4 refer to trained and untrained individuals in wheelchair sports.

Table 4 – Peak Aerobic Power in Trained and Untrained Male Wheelchair Athletes with Paraplegia

Study Mode n ISMGF

ACE – arm crank ergometer; i – incomplete lesion; ISMGF International Stoke Mandeville Games Federation functional classification; n – sample size; VO2 - Oxygen Uptake; UT – untrained participants; WA – wheelchair athletes (mixed group of athletes); WCT – wheelchair mounted on treadmill; WERG – wheelchair ergometer. Table incomplete, taken from an article by Yagesh Bhambhani (2002).

In assessing the functional capacity of C1, we must look at the mechanical and physiological performance and the relationship between them (Wüpper, 2002). Athlete C1 was able to advance to the 5^th stage (100W) for both campaigns and continue there for 1min 30s in experiment n.1 and 1min 36s in experiment n.4. From a physiological perspective he was able to generate 816.19W, representing an efficiency of 12.25% for T1, whilst in T4 he was able to generate 784.42W, representing a slightly better efficiency of 12.75%. Comparing these results with those obtained from athlete C6 who completed his test using a bicycle ergometer, it indicates that the upper limbs are less efficient than the lower limbs.

When comparing the HR reached with the maximum pre-determined HR according to the Karvonen formula (Robergs 2002, Policarpo 2004), the peak HR reached by volunteer in the two evaluative campaigns was equivalent to the pre-determined HRmax. Follow-up measurements for C1 taken 3 minutes after both tests were ended showed his HR to be below 140bpm (113bpm and 111bpm, respectively), indicating good cardiovascular conditioning given the manner in which he was able to recover. Table 4 verifies the results presented in these experiments, although the ages of those volunteers performing the tests is not included.

No fluctuation in lactate concentrations was found in respect of lactate values encountered during testing with C1, with direct readings being taken during the post-test recuperation period for both campaigns. It can be argued that the volunteer's response in the 2^nd campaign was better, noting that it took place in a transition period between vacations and the beginning of pre-season competitive training.

Aerodynamic Evaluation

The aerodynamics evaluation was intended to take account of the amount of drag produced by the athletes and generated innovative results without exposing C1 to risk. The performance of C1 over the two campaigns was very similar but he was still able to improve his results in the 2011 evaluation, conducting his test within the set parameters and recording lower values in almost all the positions carried out. As can be seen in Table 3 and in Figures 7, 8, 9 and 10, the values obtained in the test were quite consistent (Vinagre et al, 2012).

In a comparison of the results for the D values in 2011 with those of 2010, it can be seen that C1 was able to reduce the D value generated by the posture P1, which creates the most resistance.

Additionally, deterioration in the performance of P4 in 2011 can be seen, in relation to 2010. In the other previously performed positions, C1 was able to produce an improved performance for them all in 2011 in comparison to 2010, as can be seen in Table 3 and Figures 7 and 8.

However, when comparing the CD values between the two years, a greater consistency in results was seen in 2011, reflected in there being an increase in CD for all position performed following an increase in wind velocity. This was not the case in experiment n.2 in 2010 for positions P1, P2 and P3 when a decrease in CD was seen when passing to the second stage (20m/s).

Incorporating calculation of the CD according to the frontal area of the individual in the 2^nd campaign

in 2011 brought with it even more accurate values and refined data than was the case in 2010, or in other experiments from the 1970's (Bendig, 1975) conducted with the German Olympic alpine skiing team. The values of the D Area for C1 calculated from the frontal area at 30m/s represent 0.443m² in P1, 0.421m² in P2 and 0.332m² in P3.

Postural Evaluation Analysis of Lateral Photos

An analysis of the posture of C1 for both campaigns was conducted. A slight variation should be noted in that during testing for T3, C1 altered the manner in which his jacket was worn from the previous WT test, with the bottom now being pulled over the top of the sit-ski. In P1, both in 2010 and 2011, the volunteer was able to carry out and repeat the posture with only small changes in trunk position. Comparing the postures adopted in this campaign with the previous, a fundamental change in head position can be seen (in 2011, C1 holds his head lower and more to the front) and in arm position (in 2011 they are positioned further back in relation to the longitudinal axis of his body).

In P2, it can be seen that in 2010 C1 showed consistency in his performance, however in 2011 we can note that his trunk posture showed more variation. When comparing postures between the two campaigns, we can see that in 2011 C1 displayed greater trunk and elbow flexion.

In P3, both in 2010 and 2011, C1 showed a consistency in performance, indicating that this position is one that is easier to maintain and is well suited in terms of execution of the position.

Comparing the postures from both campaigns, it can be seen that in 2010 C1 assumed a position having a more rounded back, whilst in 2011 he maintained a straighter back with greater flexion of the elbows.

In P4, it can be seen that in both 2010 and 2011, despite the differing positions of holding the ski outriggers, C1 could carry out and maintain the position easily, especially when compared to P2.

When comparing the postures from one campaign to the other, it was in P4 that C1 was able to perform in the most similar way over the course of both tests.

Analysis of frontal photos

An analysis of the postures held by C1 in the frontal plane for the two campaigns demonstrates that for both 2010 and 2011, the volunteer was able to carry out and repeat the posture for P1 with minimal alterations in head, trunk and ski outrigger position, with this also being the case for P2. In P3 a small difference was seen in the positioning of the ski outriggers with them being held further from the central axis. It is interesting to compare the additional diagrams created only in 2011 from the T3 photos for positions P1, P2 and P3, which give a clearer representation of the frontal area generated by the different postures assumed by C1.

Questionnaires

Questionnaires applied in the 2^nd campaign only, provided more important information regarding the perception of discomfort through use of the Body Discomfort Diagram (BDD). C1 noted experiencing some discomfort in the thoracic region, moderate/high level of discomfort in the lumbar

region, and moderate/high to unbearable discomfort for the hips and lower limbs. Exact details of the beginning of his training season (June) were obtained and of the overall progress of his training year.

C1 trains on a daily basis during 3/4 of the year (June to March), and on some days carries out two different forms of training sessions. In the period from March to June after the competitive season has ended, the training schedule reduces with C1 completing only 2-3 workouts per week, with the emphasis being on aerobic endurance. In the months from Sept/Oct. to December, the training developed to date is maintained, reducing the weekly frequency and increasing the technical work element to 3 times a week. It is the technical training that consumes the greatest amount of the athlete's time and can extend up to 4 hours in duration. The competition season takes place in the months from Dec/January until March, and C1 tries to divide his training schedule so that 50% of his time is dedicated to physical workouts and the remaining 50% to technical and tactical training.

His best results achieved in the world of Alpine Skiing (World Championship Sestriere/ Italy), took place between the two evaluative campaigns when he finished in 3^rd place in the Slalom race.

This is an activity that demands a greater degree of manoeuvrability than required for Downhill racing (speed), in which he finished in 7^th place. It is important to point out that the season ended without him having suffered any accident or significant injury.

Contrary to what was noted on the BDD, C1 indicated in the questionnaire that he feels comfortable in his wheelchair and that he is not generally in pain. In the replies related to the WT evaluation, it can be seen that C1 was able to safely and comfortably conduct the test although he found its demands relatively difficult. He believes the test results to be important but does not know exactly how they can be incorporated into his performance and training routine. His completion of the post-test questionnaire confirmed what he had stated in the pre-test questionnaire, but added to the information that he feels the most enjoyable test position he performs to be P3.

From responses related to the test conducted at the Physiology Laboratory, it can be seen that C1 was able to safely perform the test but did not feel as comfortable, principally from a respiratory point of view and in particular, in the position requiring the trunk to be bent forward. Although he found the level of demand for the test relatively difficult, he was able to continue for as long as possible. He believes these test results to be more important than those found in the WT, in terms of his performance and training. He also believes that his training has been adapted to take into account a number of improvements from the sessions. In the post-test questionnaire, C1 confirmed his statements made pre-test, that he believes he is in a period of very good physical fitness.