Adapted sailing teaching methodology using vsail-trainer simulator as rehabilitation therapy. A feasibility study

Abstract

Context: Sailing is a sport that can help in the rehabilitation of Spinal Cord Injury (SCI) patients and improve their quality of life. Teaching methodology in sailing has always been considered as complex, due to the great amount of uncertainty that this sport has.

Purpose: To design a protocol for teaching adapted sailing in a simulated situation for people with SCI and to know the effect of the teaching protocol on learning, effort perception and heart rate.

Method: Six adults were patients recruited at the National Hospital of Paraplegics of Toledo (Spain), aged between 31 and 54 years, who have passed the early subacute phase. Each subject underwent semi-immersive virtual reality sailing therapy for 40 min per session three times per week for six weeks, 18 sessions. A simulated adapted sailing initiation program VSail-Trainer® was used for the simulator therapy. During this session, the basic notions of sailing, wind direction, sheet trimming and control of the boat on different courses were explained. The variables assessed were: sailing learning, heart rate and effort perception.

Results: The comparison of performance variables between pretest and posttest resulted differences in boat speed, heel and Velocity Made Good (VMG). These improvements in the performance variables are also reflected in the average times taken by the subjects to complete the regatta.

Conclusion: The methodology used in this study can be used as a guide for learning the activity by new SCI patients in rehabilitation who want to get into sailing sport.

Introduction

Spinal cord injury (SCI) is an injury of the spinal nerves that results in temporary or permanent sensory and motor disability, with various psychosocial consequences for the person and their family. The practice of any type of activity, whether daily or sport, can provide a stimulus to improve the quality of life of patients’ with SCI (1). In fact, Weiss and Beck (2) propose that people with SCI should be initiated as early as possible in the practice of sports for therapeutic purposes, since this largely conditions their quality of life. Despite this, it has not been until 2016 that the number of investigations has grown significantly to corroborate the benefits of adapted exercise for therapeutic purposes in people with SCI (3). Different adapted sports such as basketball, swimming, soccer or tennis, among others, provide benefits on quality of life in individuals with SCI, as shown in the systematic review conducted by Liu et al. (3). However, there is still little research on the use of sport as a rehabilitation therapy, especially in the acute phases of rehabilitation or during the first weeks after injury. This may be due to the great heterogeneity of SCI in terms of location, type of injury and, age, and also, due to lack of consensus on how to approach the teaching of sports among this population (4, 5).

For this reason, sailing is a type of sport that can help in the rehabilitation of SCI patients and improve their quality of life (6). In addition to the physical improvements caused by being a sporting activity, it shows a great integrative character and proves to have a great amount of psychological benefits as it is an outdoor activity (7, 8). Therefore, adapted sailing not only helps to break down internal barriers, but also external ones (9). Adaptive sailing facilitates greater resilience, attention, sense of control and decision making, due to the environment in which it is practiced and the uncertainty and instability that its practice produces, providing patients with greater adaptive capacity (10). The limited number of studies on adapted sailing reflect very positive results on physical, psychological and social benefits for patients with different disabilities (4–8, 10–12). The relationship between navigation and quality of life is one of the most studied relationships among different populations with mobility limitations in both, children (11) and adults(6) or in people with mental disorders or psychological disabilities (7, 8). In all of them, the quality of life has been improved after the application of real (7, 8) or simulated (4, 6, 11) navigation programs.

It was not until the mid-1980s that the French Sailing Federation (FSF) created the first standardized learning system (13). Subsequently, sailing became more popular, which led to the creation of different learning systems which were specifically adapted to each population, weather conditions, sports and type of boat, among others. All the above mentioned adaptations, resulted in the creation of a standardization of sailing teaching, based on common patterns for all boats (13). Nowadays, there are several associations of great importance at international levels, which follow their own methodology which is carried out in all their centers, as it is the case of the Royal Yatch Association (RYA), where well-defined and broken-down steps of the different phases and aspects to be learned by the beginner students are established (14).

Currently, and despite the attempts already made by associations and federations, there are no specific teaching protocols for adapted sailing. Nevertheless, it can be seen how using the sailing simulator, in initial learning phases, facilitates subjects’ safety and confidence, thus improving the learning process in people with SCI (4, 6). Recently, in a study conducted with SCI, where the sailing simulator was employed, patients were taught using two different learning protocols based on contextual interference (block practice and random practice) (15). Two groups were created, each of them followed a different type of practice, in teaching the tacking and jibing technique. No differences were found between the two groups, but the use of the sailing simulator was present during the first learning phase, proving to be a useful tool for the acquisition of basic skills for sailing in a real situation.

Therefore, a recent alternative method in teaching methodologies, is the use of new technologies, such as simulators and virtual reality (6). The usefulness of virtual simulators as a teaching tool depends on how they will be used and integrated with the rest of the sport activity and/or real practice. Simulators favor learning through experience, discovery and, in short, the rehearsal of new situations, being used in other disciplines as a therapeutic tool (16–19). The most recent study on sailing and SCI provides very positive results on factors related to quality of life after the use of virtual sailing simulators, such as improved mobility, functional capacity and self-esteem (4). Research conducted by Autry & Anderson (19), confirmed that the use of simulated sailing as a teaching tool, achieves the acquisition of basic sailing skills and motivates people with SCI to practice sailing in real situation. In the field of sailing, there are real learning simulators that can relieve the technical staff of many explanations with a strong component of dynamic spatial visualization (6). Despite the above, there is not consensus on the teaching methodology to be used in populations with different disabilities.

This study presents an adapted sailing teaching protocol for people who have suffered a SCI and are in a sub-acute phase, using a sailing simulator. Consequently, the purpose of this study was to design a protocol for teaching adapted sailing in a simulated situation for people with SCI and to know the effect of the teaching protocol on learning, effort perception and heart rate, testing two hypothesis: (a) patients would show improvement in learning after the teaching protocol; (b) patients would measure a decrease in heart rate and perception of exertion following the application of the simulator-adapted sailing therapy.

Method

Participants and design

A purposive sampling method was used to recruit participants for this study (Creswell and Poth 2018). Participants were six patients (M_age = 42.33, SD_age = 12.90, n = 3 female) recruited at the National Hospital of Paraplegics of Toledo (Spain), aged between 31 and 54 years (see Table 1 for description of participants), who were enrolled in a pre/post-intervention design. For this study, the inclusion criteria were as follow: medullary lesion lower than T1 (since patients with higher lesions would have found it very difficult to have sufficient postural control to stay upright in the simulator and during chair-simulator transfers); have passed the early subacute phase (20) and were able to start physical activity (4.2 ± 1.4 months from injury); and have no knowledge of sailing. Inclusion criteria were assessed by the hospital´s medical staff who was responsible for the monitoring of each patient.

Table 1.

Description of participants.

Participant	Sex	Age	DPI	Height	Weight	BMI	ASIA
Participant 1	M	31	102	172 cm	63 kg	21.3	T11 A
Participant 2	F	51	84	167 cm	75 kg	34.3	L2 C
Participant 3	F	35	126	167 cm	61 kg	29.9	T11 C
Participant 4	F	54	145	153 cm	59.9 kg	38.7	T9 D
Participant 5	M	51	120	175 cm	85 kg	27.8	L1 A
Participant 6	M	32	168	172 cm	63 kg	21.3	T5 A

Note: M, male; F, female; DPI, Days Post Injury; cm, centimeters; Kg, kilograms; BMI, Body Mass Index; ASIA, ASIA Impairment Scale; T, thoracic vertebra; L, lumbar vertebra; A, classification A of the ASIA scale; B, classification B of the ASIA scale; C, classification C of the ASIA scale; D, classification D of the ASIA scale.

The American Spinal Injury Association (ASIA) Disability Measurement Scale was used to assess the neurological and functional classification of SCI. This scale measures motor function, sensation and the degree of involvement of SCI. Moreover, it classifies SCI according to five grades, determined by the absence or preservation of motor and sensory function (A, B, C, D, E).

The ethics committee of the first author's university authorized the research in accordance with the Declaration of the World Medical Association (institutional review board reference number CE021912). All applicable institutional regulations concerning the ethical use of human volunteers were followed (e.g. guidelines of the Declaration of Helsinki). Informed written consent was obtained from all participants who were fully informed about the study.

Measurements

Performance variables: the following variables were measured using the VSail-Trainer® (Virtual Sailing Pty Ltd, Melbourne, Australia) with Hansa 303 model boat, which has been used in adapted sailing previously (6,15):

• Boat Speed: speed (knots) at which it is able to sail by means of the correct use of the boat's sheet and heel.

• Coefficient of variation (CV) Boat Speed: Changes in speed during navigation.

• Head (close-hauled): Degrees between the wind direction and the boat's course.

• CV Head: Variability of this angulation.

• Rudder movements: Degrees of rudder movement to control the boat´s direction.

• CV Rudder: Variability of rudder movements in navigation.

• Heel: the inclination a boat takes when it deviates from the vertical due to wind or body weight distribution.

• CV Heel: Variability obtained in heel angle.

• Velocity Made Good (VMG) from the close-hauled course: this is the optimum speed of the boat in the windward direction. The VMG is based on the following equation, incorporating speed and sailing angle VMG = V-cos(α), where V is the resultant boat speed (knots) and cos(α) is the cosine of the angle (in radians) of the boat with respect to the wind. It is expressed in knots. The higher the VMG is, the higher the performance.

• CV VMG: Variability obtained in this VMG value.

• Time spent to tack: The time taken from the start of a tack to the end of the same.

• Time: time taken to complete the course under purpose.

Heart rate: it was recorded from the beginning to the end of the measurement test using the Polar M200 heart rate monitor (Polar Electro, Kempele, Finland), with which average heart rate was collected (21).

Borg scale of effort perception: the Borg scale of effort perception measures the entire range of exertion that the individual perceives when exercising (22). At the end of the evaluation, the subjects were asked what their perception of exertion had been from 1 to 10, as indicated on the scale (23).

Intervention

Each subject underwent semi-immersive VR sailing therapy for 40 min per session, three times per week, for six weeks (18 sessions). A simulated adapted sailing initiation program VSail-Trainer® was used for the simulator therapy (4, 6). At the same time, all the participants performed the rehabilitation protocol, which was programed by the hospital's medical staff, consisting of 2 h of physiotherapeutic exercise, strengthening and mobility work, five days a week.

The VSail-Trainer simulator consisted of a boat hull, which had a length of 2.3 m, and a breadth of 1.5 m. The simulation was projected in front of the participant, simulating the real size situation (2.0 m × 2.5 m) (24). The subject controlled the simulator in the same way as in an adapted boat. The subject sits in the cockpit of the boat, holding the rudder and the sheet close at hand. The rudder is used to control the sailing angle (sailing course) and the mainsheet is used to control the mainsail, speed and heel of the boat (Fig. 1). The simulator software allows to control and modify the wind conditions and courses.

Figure 1.

Adapted sailing situation.

Previous to the pretest, and because none of the participants had previous sailing experience, a familiarization session with the simulator was conducted. During this session, the basic notions of sailing, wind direction, sheet trimming and control of the boat on different courses were explained. The instructions during this familiarization process were the same for all participants performing the same number of maneuvers, during the same practice time, with pre-designed feedback for each action, being identical for all participants. In this way, it was intended that the practice time and feedback would be the same and would not influence the result of the pretest.

The familiarization session consisted of two courses, crosswind and upwind-downwind. These courses were practiced three times with different wind intensities and heel angle of the boat. The session lasted 35 min.

After the familiarization session, a navigation level test was carried out (pretest), which has been used in previous studies with SCI (15). This test consisted of completing a regatta course with a start protocol (30 s start regatta time). The course used was a triangular buoy course, with an intensity of ten knots (Table 2). The participants had to complete one lap of this triangle course outside the buoys and cross the finish line in the shortest time. The different performance variables were collected through the simulator software. Once the intervention was completed, this same test was repeated (posttest).

Table 2.

Description session pretest and posttest.

Objectives: To know the initial level of the subjects.
Course: Timing triangular course with a start protocol of 30 s. Wind. 10 Knots Time: 5’-10’

Note: The table shows the objective of the session, the course sailed by the participants during the sailing, the wind intensity and the sailing time. The image shows the course sailed, the red arrow shows the wind direction during the whole course.

During each session of which the program was composed of, three different courses were carried out to serve as a method of learning and training different basic elements of sailing (13, 14) (Table 3). The courses were designed based on those allowed by the VSail-Trainer® software (upwind-downwind, crosswind, triangle, trapeze, large course and small course).

Table 3.

Methodology used for teaching in simulated sailing.

Session	Objectives and wind intensity	Routes
1	Practicing Cross-wind course. Understanding the difference between tacking and jibing. Learning how to trim the mainsail. Wind: 8 to 10 knots.	1. Cross-Wind course, in which the subject should go from one buoy to the other in an oval course. 2. Same circuit, but navigating in the shape of an 8. 3. Timing: time to complete 2 laps of 8-shaped circuit.
2	Refreshering Cross-wind course and maneuvers. Learning Close Reach and Broad Reach courses. Wind: 8 to 12 knots.	1. Triangular course to explain to the subjects how to do the close reach and broad reach. 2. 8-shape course on the Cross Wind course with higher wind intensity. 3. Triangular course with higher wind intensity.
3	Working close reach and broad reach and tacks-jibs. Learning run course downwind. Wind: 10 to 12 knots.	1. Triangular course using downwind legs. 2. Upwind-downwind long-distance sail. 3. Timing on short upwind-downwind course.
4	Reviewing previous sessions' courses and maneuvers. Practicing all maneuvers and courses. Attempting to improve the timed courses. Wind: 10 to 12 knots	1. Upwind-downwind course. 2. Timing of the course in the form of 8 shape course (Session 1). 3. Time Upwind-downwind course.
5	Improving tack maneuvers. Specifying the maneuvers and the number of tacks in a course. Wind: 10 to 14 knots.	1. Crosswind course with tack control at signal. 2. Upwind-downwind course, limiting the number of maneuvers. 3. Timing: time to complete crosswind course with control of turns at signal.
6	Practicing crossing the mark. Perfecting the head angle and trimming of all courses. Wind: 10 to 14 knots.	1. Trapeze course to work close-haulded to different degrees starting from the leeward buoy. 2. Timing: time to complete crosswind course with control of turns at signal. 3. Trapeze course with greater wind intensity.
7	Maneuvering control with greater wind range. Working with numerous heel changes. Wind: 10 to 16 knots.	1. Complete direct course to windward mark on a close reach course and to leeward mark on a broad reach course. 2. Maneuver training on Triangular course. 3. Time to complete course 1.
8	Improving courses, maneuvers and technical words. Practicing crossing the mark. Wind: 10 to 14 knots.	1. Course without buoys following orders. 2. Exercise crossing buoys: touch an indicated buoy and return to starting point. 3. Timing the course direct to windward mark on a close reach course and to leeward mark on a broad reach course.
9	Mid-protocol evaluation of the subjects' level of performance. Wind: 10 to 14 knots.	1. Triangular course (start 30 seconds) to compare time with the initial test. 2. Upwind-downwind course, long with regatta start protocol 2 min.
10	Sailing longer courses and longer distances. Practicing regatta starting protocol. Wind: 12 knots.	1. Trapeze course, starting from the windward buoy and having to pass each buoy downwind and returning to the starting point. 2. Practice of the starting protocol with times of 30", 1' and 2'.
11	Practicing tacking and jibing maneuvers in small spaces and different wind intensities. Wind: 10 to 16 knots.	1. Practice Square course with two marks to windward and two to leeward. Start downwind and return downwind passing through all of them. 2. Maneuvering exercise on the crosswind course with high wind intensity. 3. Timing of course 1.
12	Improving broad reach and run in high wind conditions. Working on high wind maneuvers (tack and jib). Wind: 12 to 16 knots.	1. Trapeze course (session 10) at higher wind intensity. 2. Exercise work on crosswind maneuvers. 3. Timing square course.
13	Controlling every course and maneuver on port and starboard courses in high wind intensities. Wind: 12 to 16 knots.	1. Practice trapeze course. 2. V-shaped course with high wind intensity. 3. Timing of the trapeze course.
14	Practicing every course and maneuver in both tack (port and starboard) in high wind intensities. Wind: 12 to 16 knots.	1. Practical (practice or practical?) diamond course, with 1 mark to windward, 1 mark to leeward and 2 marks in between. 2. V-shaped course with high wind intensity. 3. Timing of diamond course.
15	Working balance with constant heel changes and high wind intensity. Practicing regatta starting protocol. Wind: 10 to 16 knots.	1. Race start (5min) on Upwind-downwind course. 2. High intensity course of maneuvers in little space downwind. 3. Timing on Trapeze course (Course 1 of session 6).
16	Total control over the boat. Wind: 12 to 16 knots.	1. Race start (5 min) on Triangular course. 2. Circuit with obstacles to be avoided. 3. Timing of the diamond course.
17	Successfully following another boat. Mastering navigation. Wind: 10 to 16 knots.	1. Circuit with obstacles to be avoided. 2. Timing on Trapeze course. 3. Follow another boat.
18	Practicing regatta starting protocol. Mastering navigation. Wind: 10 to 12 knots.	1. Practice of the starting protocol with times of 30", 1' and 2'. 2. High intensity course of maneuvers in little space downwind and upwind. 3. Square course with 1-minute start protocol.

For the teaching methodology, a protocol based on the methodologies followed by the French and English federations was designed, due to the high efficiency they present in real practice (13, 14). The wind intensity was varied to cause a greater or lesser heel, depending on the course and the difficulty or intensity that would be given to the session. The wind intensity increased each week allowing patients to work at a higher intensity.

Statistical analysis

The statistical program IBM SPSS v.24.0 was used for data analysis. For each time points (pretest and posttest), descriptive analyses were conducted for the performance variables (Boat Speed, Head, Rudder, movement, Heel, VMG, Time spend to Tack and Time), Heart Rate and Perception of the Effort.

Results

Descriptive statistics are showed in Table 4. The most outstanding results with respect to the performance variables, we observe that there are greater results in the posttest, compared to the pretest, in the variables Boat Speed, Heel and VMG, these being indicators of the handling of the boat. Reductions are also observed in the Time and the Time spend to tack, after the application of the navigation protocol.

Table 4.

Descriptive statistics of each variable.

	Pretest navigation	Posttest navigation
Variables	M (SD)	M (SD)
Boat Speed (kn)	2.36 (.35)	2.79 (.30)
CV Boat Speed (kn)	0.15 (.02)	0.11 (.01)
Head (°)	49.11 (10.49)	48.87 (5.51)
CV Head	0.21 (.04)	0.11 (.01)
Rudder (°)	8.46 (2.67)	5.12 (2.76)
CV Rudder	0.32 (.09)	0.54 (.32)
Heel (°)	6.64 (2.97)	9.89 (2.81)
CV Heel	0.44 (.75)	0.28 (.15)
VMG (kn)	1.21 (.34)	1.60 (.15)
CV VMG	0.28 (.15)	0.10 (.01)
Time spend to tack (seg)	10.98 (4.15)	7.81 (2.19)
Time (seconds)	325.05 (86.97)	234.88 (30.99)
Heart rate	90.55 (16.43)	92.23 (15.32)
Borg effort perception scale	5.5 (1.04)	4.33 (.51)

Note: M = mean; SD = standard deviation; CV = Coefficient of variation; VMG = Velocity Made Good; kn = knots; ° = degrees; seg = seconds.

With regard to the physiological variables, a decrease in the score on the effort perception scale was observed after the application of the virtual sailing program.

Discussion

The purpose of this study was to design a protocol for teaching adapted sailing in a simulated situation for people with SCI and to know the effect of the teaching protocol on learning, effort perception and heart rate. Two hypotheses were examined: (a) patients would show improvement in learning after the teaching protocol; (b) patients would measure a decrease in heart rate and perception of exertion following the application of the simulator-adapted sailing therapy.

In response to our first hypothesis, the results show an increase in the results between pretest and posttest, for the variables Boat Speed, Heel and VMG. At the same time, a reduction in the time to complete the navigation circuit is observed, being a consequence of sailing faster and with a higher VMG. The performance variables assessed in the present study have been evaluated in very few previous investigations, which greatly limits the discussion of the results. There are different authors who define heel as a variable that conditions performance (26), however, none of these authors carried out a study to confirm these statements. Despite that, authors such as Mackie (27) or Chicoy (25) did study the importance of heel on sailing performance. Both researches obtained different results, due to the type of boat and the way the variable was measured. However, the results confirm that a lower variability of heel angle leads to an increase in performance. According to what has been confirmed in that previous research, we observed differences in the heel values between pretest and posttest, showing a lower variability of this, together with a higher average heel, proving that the SCI subjects are able to hold the course (close-hauled) and the correct trimming of the sail for a longer time, achieving higher sailing performance.

Moreover, time to complete the navigation course is a very determinant variable in learning navigation performance (24, 28). A higher VMG produces a reduction in navigation time. Therefore, the relationship of boat speed and time to complete the course are discussed based on the VMG results. Patients obtained better results in VMG results in posttest compared to pretest, thus demonstrating better boat handling. The VMG refers to a balance in the sailing course that allows the sailor to reach the maximum possible speed while getting as close as possible to the target (windward buoy) by sailing on a close-hauled course. There are few research studies that analyze this variable of boat performance. However, there are studies by Chicoy (25) who measures the differences in the VMG depending on the board in which the sailor sails, and the study by Menayo et al. (15), in which this variable was measured in real situation before different learning programs. If we compare the VMG results of the present research, it is observed how the VMG values are much higher in the study of Chicoy (25) (3.35 to Starboard; 3.45 to Port). This is due to aspects such as, the speed of the laser boat, higher than the hansa 303, the level of the sailors (experienced sailors vs no experience), the wind intensity used (16 knots compared to 10 knots) and the ability to hikking and reduce the heel of the boat of the subjects without SCI. On the other hand, in the study by Menayo et al. (15), when evaluating the effectiveness of two different sail learning programs in a real situation (different levels of contextual interference), they observed a trend toward an increase in VMG regardless of the learning program employed. This result suggests that the application of different activity learning programs leads to improvements in subjects’ navigation level regardless of the level of interference. The improvement in the VMG result of the present study is due to the subjects being able to maintain the straight course more effectively, allowing them to maintain boat speed and boat heel, as well as better trimming of the sail that is positioned correctly with respect to the course. These changes are produced by the learning program, in which this knowledge is worked on gradually, making the subjects perform routes of lesser to greater difficulty, with a gradual increase in the intensity of wind, making it easier for the subjects to adapt to different situations.

Regarding to the second hypothesis raised in the present investigation, the results show a decrease in the results between pretest and posttest, in the perception of effort. This is not the case for the heart rate results. These results may be due to the type of activity. Being an activity that does not require a high physical demand but rather a high cognitive demand, the subjects do not work hard enough to have high cardiac demands (28). It is unknown whether this could be different in real sailing situation, as the simulated sailing conditions do not represent the waves and stress generated by a sailing situation at sea. Research is needed to compare real and virtual sailing situations with respect to heart rate.

The use of simulators in patients’ rehabilitation is increasingly proliferating because of their dual recreational, motivational, teaching and therapeutic uses (4, 6, 15, 17, 19, 29). Performing this activity in the subacute phase of the injury allows both, sailing and exercise to be integrated into the therapy and rehabilitation that patients undergo (10). Acute and subacute subjects are learning how to live with their new injury, so it can be a great time to learn new activities. Therefore, the rehabilitation period of people with subacute SCI can be an ideal time to integrate this type of learning into the simulator, enhancing the improvement of therapy while learning a new activity. Learning new experiences during the acute phase rehabilitation process on individuals with SCI can produce an increased concentration. We believe that increased concentration combined with learning new tasks during rehabilitation may increase brain plasticity (30). In this sense, research has shown that brain plasticity at the level of the motor cortex, in its connectivity with the spinal cord, may be involved in motor recovery after SCI (31).

While the findings of the current study extend existing evidence on adapted sailing, there were several limitations that demand further study. The results should be treated with some caution due to the preliminary nature of the study, and the utilization of a small sample. Consequently, future research can extend the current study by, for example, increasing the number of patients from different hospitals.

Conclusion

The methodology used in this study can be used as a guide or as a basis for learning the activity in new users, whether they are spinal cord injured patients in rehabilitation, or people with SCI who want to get into this sport, as it is a proven methodology that produces positive results in learning. This methodology has made it possible for subjects who had no knowledge of sailing to be able to sail with solvency in just a few weeks, achieving total control of the boat in different courses and wind intensities. The simulator and the adapted sailing activity provide the subject with total autonomy and mobility, an aspect that does not occur in the real life of spinal cord injured subjects.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding None.