The effects of water exercise on bone density among postmenopausal women

1. The effects of water exercise on bone density among postmenopausal women Presented by Mushi Harush,2005 Aquatic exercise trainer specialist MA.Haifa University. Wingate Institute

2. Study hypotheses The women in the experimental group who participate in the seven-month physical activity program in water will evince no decline in bone density; they might also register an increase in bone density. If there is nevertheless a decline, it will be less than for the control group.

3. Participants Experimental group This group included 25 postmenopausal women aged 50 to 65 who met the following criteria: They no longer have their monthly cycle (menses) They do not engage in organized physical activity in any official setting They do not suffer from osteoporosis, that is, their baseline bone density is higher than 55% of mean bone density for the normal population of this age. They do not suffer from one of the following medical problems which may affect their bone density: thyroid gland problems, blood pressure problems, and diabetes. They do not take any of the following medications (which affect bones): Matrix, B complor, Betoptic, Arimidex, Cosamin, Bondormine, Glucosamine, Chondroitin, Tarivite, Normalol,, Vascace, Activelle, Normiten, Lipidal, Ocsaar, Simvastatin, Narvasc, Aspirin. They do not smoke. Method

4. Control group The control group consisted of 10 women the same age as those in the experimental group who met the same criteria as the experimental group. The following table presents a comparison of variables between women in the experimental group and women in the control group:

5. Table 1: Comparison of data for the experimental group and control group According to the data in Table 1, there were no significant differences between the two groups in any of the variables.

6. Physical measurements before commencing physical activity • – for all the women in the experimental group • Height • Weight using an electronic scale • Bone density measurement by means of DEXA in the following body areas: • Vertebrae L1-L4 • Vertebrae L2-L4 • Femoral neck of the dominant and non-dominant legs • Measurements were: • bone density in the vertebra – BMD (g/cm2), • z-score,t-score, and mineral content of vertebra • BMC (grams) • Measurement of bone density by means of Sunlight Omnisense (QUS) • in the following parts of the body: • Distal radius of dominant and non-dominant arms • Midshaft tibia of dominant and non-dominant legs • Measurements were: SOS – speed of sound in meters per second (m/sec), • t- score, and z-score.

7. Water exercise program The training program commenced in May 2003 and concluded at the end of November 2003, for a total of seven months. The experimental group worked regularly on Monday Wednesday and Thursday evenings with the same instructor (the researcher) throughout the period,. The loads applied on the bones were increased gradually. The water in the pool used for the study was warmed to 32 degrees C. Celsius, and all activity was conducted at chest level. The sessions were conducted with strict adherence to safety principles and to AEA and American College of Sports Medicine guidelines for working with elderly women (ACSM, 2000).

8. Seven month training program

9. Warm-up: 7-10 minutes This was intended to allow the body to adapt to water temperature. This part of the session included movements with short levers that gradually became long levers. Stretches performed at this stage were always at normal range of movement and included the neck, chest, deltoid, lower-back, quadriceps, pelvic, hamstring and gastrocnemius muscles. Aerobic set: 20 minutes The aim of this part of the session was mainly to improve participants‘ general aerobic ability and not bone density, although it contributed to the latter as well . Reasonable aerobic capacity was essential for participants to withstand the training load required in other parts of the program intended especially to improve bone density. Participants were directed to work at a load equivalent to the feeling of effort registering 12-16 on the Borg Scale. Furthermore, throughout the lesson emphasis was placed on proper posture.

10. Strengthening muscles and loading the bones: 20 minutes This segment worked on specific muscle groups in order to improve their strength and endurance, while raising the resistance load on bones and muscles. The activities of this segment utilized four movement patterns: compression, twisting, stretching/extension, bending, and combinations of the four. Each exercise was repeated 16 to 32 times, in accordance with ACSM guidelines (2000). Cool down and stretches: 10 minutes The duration of this part of the session depended on air and water temperature. It included static and dynamic stretches to maintain body heat and to promote proper posture, flexibility and relaxation.

11. Each session included the following components: Exercises to improve range of movement and flexibility Exercises to improve posture, and to strengthen abdominal, upper and lower back, chest and leg muscles with an emphasis on ankle-related muscles in order to prevent falls. Exercises to strengthen muscles and load bones – isotonic and isometric exercises integrating the four movement patterns (compression, stretching, bending, and twisting).

12. Equipment used in the training program • This study utilized equipment by Thera-Band (United States) • developed mainly to increase resistance to movement in water. • Aquafines Cuffs – a wing-shaped aid attachable to arms and legs that increases • resistance to limb movement in water. It was used mainly • in work on the ankle area to increase intensity of effort by the • following muscles: Hamstrings, vastus lateralis, vastus medialis, • quadriceps, gluteals, abductors and adductors. • Hand Bars – an apparatus in the shape of a hand weight • , with bar and two foamy sponge "weights." • The aid increases buoyancy and creates water • resistance to movements that try to push the bars towards • the floor of the pool. It increases resistance for arm muscles and the • upper part of the body. • Noodles – buoyant, water-resistant sponges 1.6m long • and 6cm in diameter. They are used mainly to strengthen the upper part • of the body: chest, abdominal and back muscles • (pectorals, rhomboids/trapezius, stabilizing trunk • muscles, external and internal obliques). • Pool wall – used to increase stability, strengthen muscles and increase flexibility. • Gloves – rubber-lined gloves covered with waterproof cloth. • The gloves are used to reduce gaps between fingers and thus • increasing hand surface area and water resistance.

13. Tests after the training program • Within two weeks after completing the seven months of water training, • the same type of bone density tests were conducted on the experimental • group as before the sessions. • The control group underwent only DEXA tests, seven months after the initial test. • Instruments • Electronic scale • Ultrasound: Omnisense (Sunlight, model 8000S) • DEXA: Luna model DPXIQ # 4941

14. Data processing Data were examined by means of two-way 2x2 repeated measures (ANOVA repeated measures) with group as the independent variable (between group factor). Findings Participating in this study were 35 women, mean age 55.45 years (SD=3.97), of them 25 women in the experimental group (54.9±4.45) and 10 women in the control group (56±3.49). During the training period five women dropped out of the experimental group so that only 20 women completed the study. Baseline data for the women in the study, as presented in Table 1, indicated no significant differences in age, BMI, age of menstrual cessation, number of years after last menses, and height between the experimental and control groups.

15. Findings for the DEXA tests in spinal vertebrae L2-L4 • Table 3 presents the findings for the DEXA test, comparing the • experimental and control groups for the following variables: • BMD: Bone density measured in grams per square centimeter • T-score: Number of standard deviations of BMD • values for the participant from the mean value • for a 25 year old woman • Z-score: Number of standard deviations of BMD • values for the participant from the mean value • for a women her age • BMC: Mineral content of bone, measured in grams

16. Table 3: Results of DEXA tests for vertebrae L2-L4 According to the findings, the Time factor by itself (differences between pre and post) appears to have had a significant effect only on the BMC variable. In the other dimensions no significant pre and post differences were found. On the other hand, the interaction of Time*Group was found to be significant for each of the measures. Figures 1-4 detail the interactions for each of the variables. These figures indicate the positive effect of the treatment and the general trend of bone density maintenance or increase in the experimental group, and a downward trend in bone density for the control group.

17. Figure 1: BMD values pre and post treatment in the experimental and control groups for vertebrae L2-L4

18. Figure 2: t-score values for BMD pre and post treatment for the experimental and control groups for vertebrae L2-L4

19. Figure 3: z-score values for BMD pre and post treatment in the experimental and control groups for vertebrae L2-L4

20. Figure 4: BMC values pre and post treatment for the experimental and control groups for vertebrae L2-L4

21. DEXA test findings for vertebrae L1-L4 Table 4 presents the DEXA test findings and a comparison between the experimental and control groups for the variables BMD, t-score and z-score and BMC. , Table 4: Results of DEXA test for vertebrae L1-L4 It appears that no significant differences were found for the Time factor or the Group factor, as there are no pre and post treatment differences between the experimental and control groups. On the other hand, there is a significant interaction, that is, the combination of Treatment and Group indicates a significant difference in Group behavior. The interactions in Figures 5-8 illustrate the positive effect of the treatment and testify to the general trend towards maintenance or improvement of bone density in the Experimental group and a trend towards declining bone density for the control group.

22. Figure 5: BMD values pre and post treatment for the experimental and control groups for vertebrae L1-L4

23. Figure 6: t-score values for BMD pre and post treatment for the experimental and control groups for vertebrae L1-L4

24. Figure 7: z-score values for BMD pre and post treatment for the experimental and control groups for vertebrae L1-L4

25. Figure 8: BMC values pre and post treatment for the experimental and control groups for vertebrae L1-L4

26. DEXA test findings for femoral neck density • Table 5 presents the findings of the DEXA tests and a comparison of the experimental and control • groups for the following variables: • Total BMD right: mean bone density in right femoral neck (g/cm2) • Total BMD left: mean bone density in left femoral neck (g/cm2) • Total BMC right: mean mineral content of right femoral neck (gr) • Total BMC left: mean mineral content of left femoral neck (gr)

27. Table 5: Results of DEXA test for femoral neck, right and left legs Two-way ANOVAs with repeated measures reveal no significant differences between the groups before and after treatment. Significant interaction was found only for BMC in the right leg, and it is presented in Figure 9.

28. Figure 9: Total BMC values for right femoral neck pre and post treatment in the experimental and control groups From this figure it can be seen that the women in the experimental group exhibited a trend towards improved bone density. Among the women in the control group there is a trend towards declining bone density. This interaction was found to be significant statistically.

29. QUS test findings for the proximal radius • Table 6 presents the findings of the QUS test for the • experimental group with a comparison of bone density • pre and post treatment for the following variables: • t-score: the number of standard deviations of SOS (speed of sound) values in bone density of the participant from the mean for a 25 year old woman • z-score:the number of standard deviations of SOS (speed of sound) • values in bone density of the participant from the mean • value of a woman the participant's age. • The variables were measured in values of speed of the returning • wave in meters per second (m/sec) in the following sites: • Raddom: proximal radius of the dominant arm • Radnon: proximal radius of the non-dominant arm

30. QUS test Table 6: Pre and post study QUS test findings for the proximal radius of dominant and non-dominant arms of women in the experimental group It can be seen that no significant changes were observed in the ultrasound test between the commencement and the conclusion of the program.

31. Summary of studies of water exercise and bone density

33. Researcher Harush Yurtkuran Bravo Tsukahara Goldstein

34. Summary 1. water exercise allows the option of creating the types of loads that have a positive effect on bone density 2.This study provides support for the idea that non-body-weight-bearing physical activity can stimulate bone density, Gross and colleagues(2004) assumed that integrating rest periods between loading cycles might reproduce the maximal flow effect and thus significantly increase the potential for rebuilding bone and enhancing its density 3. water exercise as performed in the present study provided the required hiatuses between loads and thereby allowed the vertebrae to respond positively. .

35. 5.the effect of water exercise on bone density of the femoral neck in the present study, a significant interaction was found between the Time variable and the Group variable only for BMC and only in the right leg (p<0.01). The meaning of this finding is that the training program increased bone density in the femoral neck of the right leg only in the experimental group, in contrast to a decline among women in the control group who did not engage in physical activity at all. At the same time, it should be emphasized that the other measures (BMD, t-score and z-score) did not register a positive effect for the treatment and no interaction was found. A possible explanation for the increase in bone density only in the right femoral neck may be attributable to the fact that the right leg is dominant for most people. As seen earlier, the professional literature offers evidence of higher bone density in the dominant side among athletes (basketball, soccer, squash, baseball and badminton players) , because of their greater and more correct use of that limb (Bailey et al., 1996) study, required symmetric, equal work by both legs which was supposed to affect bone density in both equally. Perhaps the natural tendency of the dominant leg to work harder explains the greater effect of physical activity on its bone density.

36. 6. The effect of water exercise on bone density of the proximal radius and of the midshaft tibia in the present study, no significant pre- post-differences in bone density were found using the Sunlight Omnisense apparatus among women in the experimental group These findings are consistent with the study hypothesis that among women in the experimental group there would be no decline in bone density, and the findings reinforce the conclusion that water exercise contributes to maintaining bone density. The effect of water exercise on bone density of the tibia and the radius was tested only for the experimental group, and without data on the control group it is difficult to draw clear conclusions about possible effects of the treatment on the experimental group At the same time, and even though no differences were observed in bone density of the proximal radius and themidshaft tibia, it was possible to identify in both of them an increase in density of the dominant limb in contrast to the non-dominant limb This increase might actually signal a rise in bone density but this is only supposition as the change was not significant.