Author: Sensei Lincoln

It is assumed that to participate in karate at the elite level, flexibility and strength are absolute musts for both legs. (Tippett and Voight, 1995 p65). This is because of the number of kicks practiced (both to the upper and lower body) and the amount of dodging, weaving, shuffling etc that takes place whilst fighting or sparring. Many karate movements require long, deep stances, stances which put an enormous amount of pressure on the groin and hamstrings. (Michaels, 1993 page unknown). With this in mind, it is only logical that deficiencies in these areas can severely retard the progress of the elite karate practitioner.


The training program "Range of Movement and Strength Enhancing Training Program for the Groin and Hamstrings" was undertaken by Lincoln McConnell-Brown over an eight week period. The aim of the program was to improve hamstring and groin range of movement and increase the general strength of these areas. The initial program consisted of two karate training sessions, four stretching sessions and a swim, jog and weight session every week. The adjusted program completed varied markedly to the initial plan due to two factors - illness during week five and a knee injury occurring prior to week eight. Adaptations were made to the program because of these factors and also in light of previous research suggestions. Results of the program have been favourable, with the subject recognising limited increases in flexibility and strength in the areas mentioned. These improvements may have been retarded by the illness and injury. Changes to the program in future would include more Proprioceptive Neuromuscular Facilitation exercises and a greater emphasis on weight training.


Objectives of the program.

Being heavily involved in the Martial Arts (namely Karate), I have come to understand the importance of stretching. This importance should not be underestimated as a typical karate training session can involve anything up to five hundred plus kicks. These kicks are often directed at head height, so the need for flexibility and local strength is great. During this training in the past four years, I have sustained numerous groin and hamstring injuries. These injuries result in me having to undertake rehabilitation programs - programs that result in reduced training time and a decrease in skill and fitness levels. These injuries often take place time and time again, with concominant changes in muscle function occurring. These changes include muscle flexibility and strength. (Herring, 1990 p453). As literature has suggested, more often than not, I have experienced a performance drop-off rather than pain or swelling. (Herring, 1990 p453). Hence, the objective of this case study is to improve my hamstring and groin flexibility and strength to allow my legs to keep up with the demands of high intensity leg training, and reduce the likelihood of future injury.

The perceived needs of the client.

As the client, and Victorian Assistant Instructor, it is important that I lead by example and are able to train 100% and not be continually sidelined with minor and major upper leg injuries. With the nature of karate, it is virtually impossible to set intangible needs. However, when fit, I should be able to kick to head height repeatedly without any encumbrance.

An explanation of the balance between the lifestyle needs of the client and what is required to achieve the objectives.

Being an extremely busy client, I am able to devote four training sessions per week to the implementation of the training program. Each of these training sessions can range up to forty-five (45) minutes in duration. I believe this is sufficient time (eight weeks multiplied by three hours) to assist in correcting my specific deficiency. This time, added to my usual two (2) nights per week of standard karate training should see my flexibility improve.

It should also be noted that these sessions will "fit-in" around my schooling commitments, and hence, I will have no set time every day to complete the session. More often than not they will be completed in the late afternoon, after school.

Assumptions made.

It is assumed that to participate in karate at the elite level, flexibility and strength are absolute musts for both legs. (Tippett and Voight, 1995 p65). This is because of the number of kicks practiced (both to the upper and lower body) and the amount of dodging, weaving, shuffling etc that takes place whilst fighting or sparring. Many karate movements require long, deep stances, stances which put an enormous amount of pressure on the groin and hamstrings. (Michaels, 1993 page unknown). With this in mind, it is only logical that deficiencies in these areas can severely retard the progress of the elite karate practitioner.

Rationale and Justification for the Program.

Starting point.

This training program is primarily geared toward improving flexibility, and to a lesser extent, strength. With this in mind, most sessions will consist of approximately 30 minutes of stretching, and occasionally a light jog. The definition of the starting point of the program, or more specifically, the initial stretching session, is a very subjective one. Being the subject, I am well aware of how far my hamstrings and groin can be stretched before severe discomfort (and pain the following day) occurs. Knowing that it can take several weeks before benefits from the training program are realised, the starting point will be quite low and not excessively strenuous. (Stanish and McViccar, 1994 p115).

Mode, intensity, duration, frequency and progression of each exercise.

This training program consists of four types of sessions - stretching, running, swimming and weight training/strengthening.

A. Stretching:

The entire training program revolved around these sessions. Essentially, these sessions are looking at reducing the likelihood of further injury in the future. Flexibility training is aimed at improving "suppleness". Fyfe and Stanish (1992, p611) believe that stretching helps to increase the length of the muscle tendon unit, and therefore reduce the strain with joint movement. Stanish and McViccar (1994, p270) recommend that the best method of stretching to incorporate into a program is static

stretching. Static stretching involves placing the muscles (namely the groin and hamstrings) at their greatest possible length and holding them in that position. (Anderson and Burke, 1991 p65). However, recommendations as to the optimal time for holding each stretch vary. Knott and Voss (cited in Prentice, 1994 p43) suggest that a stretch can be held from as short as 3 seconds to as long as 60 seconds, while Davis, Kimmet and Auty propose that a static stretch be held for 30-45 seconds. (1991, p155). With these differing opinions, it was concluded that for this training program, each stretch will be held from 45-60 seconds, and be completed five times. (Prentice, 1994 p388).

As this program is designed to enhance my already poor flexibility, the static stretching method was the one employed here. Importantly, research has shown that static stretching generally does not cause muscle soreness and is commonly used in injury rehabilitation of sore or strained muscles (Prentice, 1994 p43), and is used in training programs such as these. Stone (1990, p458) believes that flexibility training is one of the primary elements of a training program designed to enhance muscle conditioning and reduce muscle injuries. For this reason, all four training sessions per week will be principally devoted to flexibility training.

Essentially, the progression of the intensity is subjective, and depends upon the subjective complaints of the individual (namely myself) (Stanish and McViccar, 1994 p266). If my legs are feeling good, I will push the stretch a little harder.

Flexibility training will take place mostly at my home, but will also be conducted before the strength sessions and the swim sessions.

A representation of what stretches were conducted during each session can be found in appendix 1.

B. Running:

Running will be performed to help add strength to hamstrings and to a limited amount, the groin. Running is also useful as a "loosening" exercise both before and after stretching. (Assumption 1). Intensity of each running session will slowly increase throughout the 8 weeks of the session, beginning at 45 % of max heart rate and concluding at 70% of max heart rate. The notion of the running sessions is not to increase aerobic endurance, but more to promote movement of the legs. For this reason, the percentage heart rate desired should be enough to guide me as to how much work I am doing, and that there is progression in the amount of stress my legs will be under. (Assumption 2).

Each run will last for between 15 and 30 minutes and be conducted 1-3 times per week. This allows time for the legs to gain some benefit from the load bearing activity, and to remain "loose". (Assumption 3).

The running sessions will be conducted throughout the streets around my home.

C. Swimming:

Swimming will be conducted through a once per week, 45 minute swim. The purpose here is to assist in increasing groin and hamstring flexibility and to a limited amount, strength. (Prentice, 1994 p390). Swimming provides a mild resistance to the legs as you swim. The reason why only one swim session will be undertaken is due to a lifestyle factor. I do not have enough time in a week to swim more than once.

Each swimming session will be of 30-45 minutes in duration and have an intensity of 60-65% of maximum heart rate. Again, the aim of the swimming session is not to improve aerobic fitness, but to promote movement of the legs against a resistance (water). Hence, percentage of maximum heart rate attained is not that important and therefore there will be no objective, numerical figure of progression rate. (Assumption 4).

The swim sessions will take place at the Broadmeadows Leisure Centre.

Appendix 2 contains details as to what was actually performed during the swim sessions.

D. Weight Training/Strengthening.

Weight training is an important part of most training programs. Stretching programs conducted after injury (chronic or acute) should always include some type of strengthening agenda. (Balduini, 1988 p354).

The weight training session primarily involves leg curls to build strength in the hamstrings and hip adduction/abduction work to assist with groin strength as suggested by Prentice, 1994. (p337). The weight sessions will be fairly "gentle", in that they will involve 3 sets of low weight with high repetition, and will progress in weight in a limited manner. (Assumption 5). (Note. This was to later change. See modifications section for details). For the adductor/abductor work, no set number of repetitions is set, I will just complete the activity until I cannot continue (due to lactate build-up etc).

The weight sessions will take place at Victoria University of Technology gymnasium and involve the use of the leg curl bench (hamstrings) and my own personal leg weights for adductor/abductor work.

Appendix 3 highlights the strength activities undertaken during the program.


The volume of the specific groin and hamstring stretching program is directly related to my lifestyle. As I train for karate twice a week and work three times a week, this stretching program needs to work in around that. For this reason, four short sessions of 30-45 minutes will be completed rather than three larger ones of one hour in duration.

It must be noted here that throughout the duration of the eight week program, I refrained from any kicking activities what so ever during my normal Karate class. (Assumption 6). Even though I stretched before each class, my training emphasis was on upper body work.

Modifications to the Program.

From the initial training program on pages 6 and 7, a number of changes were made. These changes were made for a number of reasons, including illness, injury and more streamlined guidelines for the implementation of the program because of past research. This section merely identifies each of the changes with a number which corresponds to that number in brackets in the Modified and Completed Program on pages 15 and 16. The justification for these changes can be found in a later section.

The changes were:

(1). Jogging was completed before each stretching session, not afterwards.

(2). The stretching and swimming sessions were moved from Tuesday to Monday (Week 3).

(3). A strength preparatory session was held on Wednesday (week 3).

(4). An extra stretching session was added.

(5). The training program was halted for 7 days during week 5.

(6). No swimming session was completed on the Tuesday of week 6.

(7). Strengthening session modified.

(8). Swimming sessions were abandoned after the session in week 6.

(9). Weight session added.

(10). Training program altered significantly due to injury in week 7.

(11). Acute injury care takes precedence during final days of program.

(12). Strengthening program adapted because of injury.

(13). No jogging or running session completed post injury.

Rationale and Justification of the Modifications.

The following section provides the rationale and justification behind all of the changes that occurred throughout the duration of the training program.

Change (1).

The first adaptation to the training program came during week 1. On the Sunday during this week, I decided that the jog was to be completed before the stretching session took place and actually used as a "warm-up" - one aspect of training I had ignored prior to the commencement of the program. Previous research has suggested that temperatures above 40 C relaxes the collagen fibres found in the muscle, and thus assisting the stretch. (Stanish and McViccar, 1994 p112). Such temperatures mean that less force is required to produce the same deformation of the muscle-tendon unit or that the same force produces more elongation. (Safran, Seaber and Garrett, 1989 p244). Further, Stanish and McViccar (1994, p270) emphasise that stretching exercises should be preceded with a mild warm-up - such as the 15 minute jog that took place before each stretching session.

Change (2).

The stretching and swimming sessions were shifted away from Tuesday and completed on the Monday. This was because I was required at Karate training on Tuesday nights because the Chief Instructor found it difficult to be at class on time because of work commitments.

Change (3).

A strength training "preparatory session" was conducted on the Wednesday of week 3. This session took place because I felt cautious about the weight training and what effect it would have on my hamstrings. Therefore, I decided to still continue with the session, but just with lighter weights and increased repetitions. (Davis, Kimmet and Auty, 1991 p145) (Assumption 7).

Change (4).

On Sunday during week four, I undertook a supplementary stretching session. I had just spent eight hours at work on my feet and felt very stiff. Anderson (1980, p10) suggested that you should stretch when you feel stiff or after standing for a long time. Hence, this session took place.

Change (5).

From the Tuesday of week 5 to the Monday of Week 6, I was very ill with gastroenteritis. I visited our family Doctor on the Thursday. He gave me an antibiotic injection and suggested I take a few days off school and work. For this reason, I spent the next three days in bed. I still felt ill during week 6, but was fit enough to recommence the training program on Tuesday.

Change (6).

Due to the fact that I still felt ill, no swimming session was undertaken on the Monday or Tuesday of this week.

Change (7).

On the Wednesday of week 6, the weight training or strengthening session was drastically modified. With one of the objectives of the training program being to develop strength, I believed that an adaptation to the strength sessions was required. A number of researchers, including Davis, Kimmet and Auty (1991, p145) have found that the optimal method of improving muscular strength involves the use of very heavy weights (80-95% of maximum lift weight) with low repetitions of 2-6. This framework should be incorporated into 5-12 sets. (Davis, Kimmet and Auty, 1991 p145). With this in mind, the appropriate adaptations were made to the program, where a high weight of 60 kgs was lifted 4 times over 5 sets.

Change (8).

At the commencement of week 7, I decided to abandon the swim sessions. I found that the swim sessions were not having a great influence on my flexibility, and with this, I could find no literature that suggested that swimming can be highly successful in promoting flexibility. I believed that if anything, the swim sessions were more useful and as strengthening activity. (Assumption 8).

Change (9).

Instead of the above mentioned swim session, I decided to emphasise the strengthening training by adding in an extra weights session. Some authors believe that for strength gains to be made, up to 4 sessions per week should be completed. (Walsh, 1990 p107). With this information, it was decided to add an extra weights session to the program and delete the less useful swim session. (Assumption 9).

Change (10).

During week 10, a major change occurred with the program. On the Thursday night, I seriously damaged my left knee. It seemed to collapse on me whilst performing some shifting and twisting footwork drills at Karate. Upon visiting my physiotherapist, Paul Sortino, it was identified that I had suffered a grade 2 lateral collateral ligament tear. This ligament is found on the outside (lateral) aspect of the knee and serves to limit the amount of rotation that is possible by that joint. (Spence, 1990 p170). On the advice of my physiotherapist, I was to discontinue activity for at least 3-4 weeks. However, it was still possible to complete some aspects of the training program with the use of only one leg.

Change (11).

During the final days of the program, I undertook a rigorous acute injury rehabilitation plan. This involved the implementation of the RICE method of acute injury care as instructed by my therapist. Twice a day, (school work and time permitting) I iced my knee for 20-30 minutes. Rest and elevation was also completed for the first 72 hours post injury. (Reilly, 1992 p256).

Change (12).

The strengthening program had to be modified for the fact that I was unable to use my left leg because of my therapist’s recommendations. The sessions continued however, but only my right leg was used, and my left leg was sedentary. (Assumption 10)

Change (13).

No jogging or running was completed after the knee injury had occurred. In agreeance with Paul Sortino, Prentice (1994, p411) suggests an elimination of weight bearing activity for grade 2 lateral ligament injuries for up to 2 weeks. From this information, no running or jogging was undertaken and walking was only done minimally. However, the stretching sessions continued.


The actual outcomes of the prescription.

On the 20-3-96 a pre-test was performed at Victoria University of Technology. On the 29-5-96, the post-test was performed at the same venue. The table below indicates the results of that test which was determined to be relevant to my program and its aims.

Table 1. Pre and post test results.

Pre test sit and reach 2 cm

Post test sit and reach 7.5 cm % improvement = 26.7%

As mentioned in the "Assessment" section on page 4, with karate, it is virtually impossible to set intangible needs. Whether or not the training program has fulfilled its aims and objectives is almost completely subjective. However, the table above does indicate a 26.7% increase in hamstring flexibility since the introduction of the flexibility program. This is very positive in that it shows that progression has been made to some extent.

To further address whether or not the training program has been a complete success, actual skills tests over time need to be conducted within the karate training environment. For example, if I find it easy to kick "head-height" repeatedly and with no pain at training in the future, then it can be concluded that the training program was a success. From a subjective viewpoint, I feel very relaxed in the groin and hamstrings, and have not had any pain there over the past 8 weeks. Unfortunately with the knee injury sustained, the exact extent to which the training program has helped my specific deficiency (groin and hamstring injuries over time) cannot be determined for some weeks. I will still be unable to participate in karate training or do any kicking activities for at least another 3-4 weeks.

I am sure though that the training completed over the past 8 weeks has assisted my flexibility in both the hamstrings and groin. To a limited extent, the results in table 1 support this notion.

Discuss the problems or difficulties which were encountered.

The majority of the difficulties I encountered were ones that were out of my control. Illness and injury were the major obstructions to my successful completion of the program. Also, time management became an issue, as did motivation.

1. Illness/injury.

Illness and injury were major disappointments and problems that needed to be overcome. Unfortunately with the illness, I was virtually restricted to bed for three full days, and still felt quite ill for another day or two. This meant that I was unable to do any training at all, which really set the program back a week. Further, when I did recover, I did not complete the swim session because I still felt "weak" and had a "lack of energy". For this reason, the training program was probable interrupted for approximately one and a half weeks until I was fully recovered.

The injury I sustained also made completion of the program difficult. The lateral collateral ligament injury meant that I was unable to weight bear, and hence, was unable to run. Because I do not have a bicycle and could not run, the warm-up would not be completed before the stretching sessions. This increased the possibility of injury from the stretches themselves, and reduced extensibility and flexibility. (Safran, Seaber and Garrett, 1989 p246). Because of this, I do not believe I attained the best possible results from the stretching sessions during the final week of training. The final week saw the stretching sessions being completed "easily", that is without too much pressure and for only 20-30 seconds. (Anderson, 1980 p13). This was enough to be used as a "maintenance" stretch (to remain at the level of flexibility already attained). However, the risk of further injury refrained me from continuing with the developmental stretches that were held for 45-60 seconds. (Assumption 11)

I learnt a lot regarding "time management" over the duration of the program. Quite often, I would not have time to complete a session because of homework, football commitments, work commitments or karate teaching commitments. Nevertheless, I knew that the sessions had to be completed, and so I found time to fit them it. Sometimes, I would not complete a session until 10 o’clock at night because that was the only time I had free to train.

This program has taught me much about designing programs that are "user-friendly" - that is, they fit in easily with the athletes current commitments and existing training schedule. More on this in a later section.

I also found that towards the end of the program, my motivation began to fall. After just getting over an illness, and then having to contend with the knee injury all became a bit much. In my own mind, the training program was not as important as trying to recover from the injury. That is why the stretching sessions were shorter during the final week - I really just did not want to do them.

What would you change?

If I was to complete an 8 week stretching and strengthening program in the future, I would make the following changes...

1. Include PNF techniques. Since completing the program, I have found research suggesting the Proprioceptive Neuromuscular Facilitation is most beneficial in rehabilitation and stretching programs. During one research study, results showed that the PNF technique can generate about twice as much hamstring EMG activity as static stretching methods, which correlated to approximately 9-13% better range of movement around a knee joint. (Osternig, Robertson, Troxel and Hansen, 1990 p108). Such techniques have shown to improve strength in weak muscles as well as improving range of motion or flexibility. (Prentice and Kooima, 1986 p30). A technique that can improve both strength and flexibility such as PNF should be included in future training programs such as this.

2. Include lower back stretches. The hamstrings attach to the ischial tuberosity found on the pelvic girdle. (Spence, 1990 p231). Because of where they attach, ight hamstrings prevent the pelvis from tilting correctly when bending forward. This forces all movement to come from the lower back. (Pullig-Schatz, 1994 p115). Hence, stretching of the lower back can prevent tight hamstrings. For this reason, future programs should include a number of lower back stretches.

3. Different types of strength training. Rutherford (1988, p201) has questioned the validity of appropriateness of conventional weight lifting exercises above completing everyday activities under load. For example, throughout the duration of this program, I refrained from any kicking. (Assumption 6). It may be that completing kicks slowly with ankle weights on not only improves strength, but allows the athlete to continue to practice all aspects of karate (punches, blocks and kicks) to some degree and does not lose skill in kicking. I do not believe this type of training can substitute traditional resistance training, but may heighten its effectiveness. (Assumption 12).

4. Time of year of program. This is a very difficult change to make because training programs usually are undertaken because of a need for rehabilitation, fitness improvement or training for an event. For me, this program took place at a very difficult period in my life - a period full of homework and working on weekends for an income. This program may have been easier to complete during school holidays for instance, or during the end of season break for an elite athlete. However, the nature of this project required that it be completed during April and May. When prescribing exercise in future, I will pay close attention to the client’s lifestyle and how much time they can actually devote to the implementation of the program.


Assumption 1.

It was assumed that gentle, light running relaxes the legs and promotes a feeling of looseness within the legs, both before and after exercise.

Assumption 2.

Heart rate should give an indication of how hard the legs are working during running. A low heart rate usually corresponds with a low work rate from the legs and vice-versa. Increasing heart rate will coincide with an increased rate of work from the legs. If this is occurring, flexibility and strength within the legs can be seen to be improving.

Assumption 3.

There is a benefit gained by the legs through load bearing activity. Load bearing activity can improve bone mineral density etc.

Assumption 4.

Heart rate while swimming is not as important as the fact that the legs are working against a mild resistance. Not being a very good swimmer, heart rate is not an accurate indicator of work done by my legs during these sessions.

Assumption 5.

It was initially assumed that light weights with high repetitions would be adequate to improve strength. Research has proven this notion to be incorrect, and hence, the program was adjusted appropriately.

Assumption 6.

Advice given by Richard Walsh of the Human Performance Laboratory at Victoria University of Technology to refrain from any kicking at karate training for the duration of the training program.

Assumption 7.

I believed that a light, initial weights session might be good to give my legs a chance to work against a resistance - something they have not done for months.

Assumption 8.

Swimming can primarily be used as a strengthening activity.

Assumption 9.

I assumed that a traditional weights session may be more beneficial than a mildly resistive swimming session. Because I did not have time to include two weights sessions and a swim, I decided to delete the swim session.

Assumption 10.

Continuing to train and stretch only one leg post injury was better than completing no stretching at all.

Assumption 11.

I have assumed that a "maintenance" stretch be used to keep flexibility at its present level, and that such a stretch be of 20-30 seconds in duration. The developmental stretch will improve flexibility and be of 45-60 seconds in duration.

Assumption 12.

Kicking whilst wearing leg weights may prove a beneficial supplement to traditional weight training programs.


1. Stretches conducted during each stretching session.

2. Work completed during each swim session.

3. Exercises completed during each weight session.

4. Appendix 1. Stretches completed.

Derived from Anderson and Burke, 1991 and Spring, Illi; Kunz, Rothlin, Schneider, and Tritschler, 1991.

Appendix 2. Swimming session completed.

Broadmeadows Leisure Centre, 25 metre pool

1. Warm-up. 1 lap freestyle (very slow)

Max HR- 198bpm

60% = 119bpm,

2. Flexibility/strengthening. 2 laps freestyle monitor heart rate

2 minutes rest

2 laps breaststroke monitor heart rate

3 minutes rest

2 laps freestyle monitor heart rate

3 minutes rest

2 laps breaststroke monitor heart rate

2 minutes rest

3. Cool down. Walk 2-3 laps

Complete 10 minutes of stretches.

Appendix 3. Weight session completed.

Derived from Prentice (1994).

Reference List

1. Anderson, B. Stretching.Shelter Publications, California. 1980.

2. Anderson, B. and Burke, E. "Scientific, medical and practical aspects of stretching". Clinics in Sports Medicine. 10(1), January 1991, pp63-87.

3. Balduini, F. "Abdominal and groin injuries in tennis". Clinics in sports medicine. (Philadelphia) 7(2), April 1988 pp349-357.

4. Davis, D; Kimmet, T. and Auty, M. VCE Physical Education. Book 2. Macmillan Education Australia Pty Ltd, Vic. 1991.

5. Fyfe, I. and Stanish, W. "The use of eccentric training and stretching in the treatment and prevention of tendon injuries". Clinics in Sports Medicine. 11(3), July 1992, pp601-624.

6. Herring, S. "Rehabilitation of muscle injuries". Medicine and Science in Sports and Exercise.22(4), 1990, pp453-456.

7. Michaels, A. "Strong and Stretched". Martial Arts Training. May, 1983.

8. Osternig, L; Robertson, R; Troxel, R. and Hansen, P. "Differential responses to proprioceptive neuromuscular facilitation (PNF) stretch techniques". Medicine and Science in Sports and Exercise. 22(1), 1990, pp106-111.

9. Prentice, W. Rehabilitation Techniques. Mosby, Missouri. 1994.

10. Prentice, W. and Kooima, E. "The use of proprioceptive neuromuscular facilitation techniques in the rehabilitation of sport-related injury". Athletic Training. Spring, 1986, pp26-31, 80.

11. Pullig-Schatz, M. "Easy hamstring stretches". The Physician and Sportsmedicine. 22(2), February 1994, pp115-116.

12. Reilly, T. Sports Fitness and Sports Injuries. Wolfe Publishing Ltd, London. 1992.

13. Rutherford, O. "Muscular coordination and strength training". Sports Medicine. 5, 1988, pp196-202.

14. Safran, M; Seaber, A. and Garrett, W. "Warm-up and muscular injury prevention". Sports Medicine. 8(4), 1989, pp239-249

15. Spence, A. Basic Human Anatomy. The Benjamin/Cummings Publishing Company, Inc, California. 1990.

16. Spring, H; Illi; U; Kunz, H-R; Rothlin, K; Schneider, W. and Tritschler, T. Stretching and Strengthening Exercises. Thieme, Germany. 1991.

17. Stanish, W and McViccar, S. "Flexibility in Injury Prevention". Source unknown.

18. Stone, M. "Muscle conditioning and muscle injuries". Medicine and Science in Sports and Exercise. 22(4), 1990, pp457-462.

19. Tippett, S and Voight, M. Functional Progressions for Sport Rehabilitation. Human Kinetics, USA. 1995.

20. Walsh, B. Strength Training for Australian Rules.Kangaroo Press, NSW. 1990.