Descripción del instrumento # 4, entrevista a docentes

Grip strength data analysis

The experimenter gave verbal encouragement and it usually took 2-3 grip attempts for maximum to be reached. The best of 3-5 grips was taken as maximal grip force.

Hand torque data analysis

Typically, subjects would gradually increase their torque production and plateau for about 1-3 secs (Figure 78). 2-3 repetitions were carried out and the value taken for each subject for the session was the highest of the 3 repetitions.

( h a p te r ft: S tr e n g th tra in in i; stu d y <a 3 O ’ 1.6 1.2 0.8 0.4 0 0 1 2 3 4 5 Time (s)

Figure 78. Example of a typical torque trace. Notice that the subject increased torque gradually, reached a peak and held it more or less steadily. The average torque in the pink region of the trace is taken as the measure of maximum torque for this trial.

6.2.5. Statistical tests

All results are presented as mean and standard error (± s.e.m.). Paired and unpaired t- tests, one-way and two-way ANOVAs with post hoc Tukey tests were used.

6.3. DESCRIPTION OF GROUPS

Subjects were recruited by adverts or by posters requesting volunteers to take part in this training study. These adverts were placed at the University of the Third Age, in a local newspaper (The Hendon Times), in the RNOHT newsletter (Royal National Orthopaedic Hospital, Articulate), and posters around the RNOHT, and the British School of Osteopathy (see adverts in Appendix III). A total of 89 subjects responded to these adverts. Respondents were sent a questionnaire to return and participation was taken after assessing these questionnaires. This questionnaire covering health, life style and activity was adapted from the Allied Dunbar Fitness Survey and from a health questionnaire used by Greig et al (1994), and is shown in Appendix IV.

ClitijU cr 6: Strciv^ ili tn iin in q stu d y

We were aiming for three serum oestrogen groups: high (premenopausal women), medium (postmenopausal on HRT), and low (postmenopausal not taking HRT). All subjects had to be reasonably healthy, able to train the hand at the required intensity without much discomfort and able to attend 5-6 measurement dates in the laboratory at low financial cost. Ideally we would have liked age, number o f years postmenopausal and BMI (body mass index in Kg/m^) to be the same in the medium and low oestrogen groups. By selecting fi*om the volunteers, some limited matching for these was achieved but the number of respondents to adverts was not sufficiently high to obtain a good match for age and number o f years postmenopausal.

17 subjects were excluded due to our selection criteria, leaving a total o f 72 subjects. O f these a further 38 were excluded, as they did not reply to our invitation to come to the laboratory for preliminary testing. The remaining 34 subjects attended the preliminary testing session and gave their informed consent to participate in training. Five o f these subsequently withdrew from the experiment due to personal circumstances. Thus, the data of 29 female subjects was eventually analysed.

Our 29 subjects were grouped according to oestrogen status (seven young normally menstruating women using oral contraception (T), eight postmenopausal women not using HRT (No n) (and who had never used HRT in the past) and fourteen postmenopausal women on HRT (H)). Below are some characteristics o f these subjects.

There are no significant differences between the three groups in height, weight and BMI. The HRT group is significantly younger (p=0.017) but not significantly closer to the menopause than the non-HRT (p=0.081). This is expected since women usually stop HRT some 10-15 years after the menopause, hence the difficulty in recruiting younger postmenopausal non-HRT women. Although the No n sub-group was taking

significantly more exercise (walking, cycling etc.) than the Y sub-group (p=0.025), the population as a whole were matched for daily home activity levels and attitude to exercise (see table 15).

C h a p te r (r. S tr e n g th tra in in g stu d y

Table 15: Training population characteristics

Age (years) 68.1 ±2.40 60.1 ± 1.90 35.4 ±2.58 56.4 ± 2.63 N °years P.M.* 20.3 ±3.87 12.3 ± 1.90 N /A 11.5 ± 1.94 Body height (cm) 162.4 ±1.56 162.4 ±1.90 169.3±2.57 164.1 ±1.28 Knee height (cm) 47.1 ±0.63 46.9 ± 0.60 48.9 ± 1.03 47.4 ± 0.44 Demi span (cm) 86.8 ± 1.97 84.0 ± 1.31 86.3 ± 1.08 85.4 ±0 .88 Body weight (Kg) 63.6 ±2.88 65.9 ±3 .49 64.1 ±6.03 64.9 ± 2.29 BMI (Kg/m^) 24.2 ± 1.16 24.9 ± 1.2 22.7 ±2.70 24.2 ±0.91 Home activities 7.88 ± 0.38 7.82 ± 0.37 7.79 ± 0.43 7.83 ± 0.22 Exercise (mins pw) 612.5 ±125.89 322.7 ± 79.78 242.9 ±73.01 383.4 ±59.55 Attitude 0.84 ±0.14 0.99 ± 0.07 1.10±0.18 0.98 ± 0.07

Notes. Data are means ± s.e.m. * Is the number of years post-menopause. Levels of home activities, exercise activities and attitude (to health and exercise) were assessed using a questionnaire (see appendix IV for questions and interpretation of answers)

Figure 79 shows the muscle strength before training for both hands. In each group, the dominant hand is stronger than the non-dominant by 5-8N (average of 6.8±0.82N). As expected, the strongest group is F, and the weakest is Non, with H intermediate. To assess the significance of this trend, a two-way ANOVA with hand and group as variables showed no significant main effect of group (p=0.052) or hand (p=0.081).

65 60 4 55 z IT 50 > s .Ü 45 o E 40- o « 35 30 4

Non-HRT (8) N HRT (14) H Young Females All females (29) (7) Y

Non-Dominant □ Dominant

Figure 79: Mean isometric MVF values ± s.e.m for the three groups before training.