O M Rutherford’s research while affiliated with King's College London and other places

Objectives: Falls Management Exercise (FaME) has been shown to reduce falls in frequent fallers and in lower risk sedentary older people. The effects of FaME on the strength, power, physical function and bone health of frequently falling older women are yet to be established. Methods: This paper reports secondary analysis of data from the original randomised controlled trial of FaME in 100 community dwelling women aged ≥65 years with a history of ≥3 falls in the previous year. Intervention was group delivered, weekly one hour tailored dynamic balance and strength exercise classes and home exercise for nine months. Outcome measures included: strength (handgrip, quadriceps, hamstrings, hip abductors, ankles), lower limb explosive power and functional tests (timed up and go, functional reach, timed floor rise and balance), analysed using Linear Mixed Model analysis. Bone Mineral Density (BMD) at hip and spine was measured in a smaller sub-group and analysed using t-tests. Results: Significant time*group interactions in all measures of strength, except isometric ankle dorsiflexion, concentric hamstring and eccentric quadriceps strength. These improvements in strength equated to average improvements of 7-45%. There were also significant improvements in explosive power (W/kg) (18%, p=0.000), timed up and go (16%, p=0.000), functional reach (17%, p=0.000), floor rise (10%, p=0.002) and eyes closed static balance (56%, p=0.000). There was a significant loss of hip BMD in the control group (neck of femur p<0.05; ward's triangle p<0.02). Conclusion: The FaME intervention improves lower limb strength, power and clinically relevant functional outcomes in frequently falling older women.

Anterior cruciate ligament (ACL)-injury rate is greater among female athletes than among male athletes. To investigate the rate and risk of ACL injury among Slovenian sportswomen playing professional basketball, team handball, or volleyball. Prospective cohort study. The Slovenian National Organizations of basketball, team handball, and volleyball. During the 2003-2004 season, we prospectively followed 585 Slovenian sportswomen registered in the Slovenian National Organizations of basketball, team handball, and volleyball. We asked sportswomen and coaches to document the occurrence of every significant traumatic knee injury requiring medical attention. Injury rate and injury risk were calculated for sportswomen in each sport group. To calculate injury rate, we estimated the average exposure of each sportswoman during the research period. During the 2003-2004 season, 585 Slovenian sportswomen sustained 12 ACL injuries. The ACL-injury risk was different in athletes participating in the various sports, with basketball players having the greatest ACL-injury risk and volleyball players having the lowest ACL-injury risk (P  =  .04). The risk of ACL injury among Slovenian sportswomen was 2.1 per 100 athletes (95% confidence interval  =  0.9, 3.2), whereas the rate of ACL injury was 0.037 per 1000 exposure hours (95% confidence interval  =  0.016, 0.06). Overall differences in injury risk were found among sports, but no differences were noted among divisions within sports. No differences for injury rate were observed between or within sports. The rate and risk of ACL injury among Slovenian sportswomen are high, with basketball players having the greatest ACL-injury risk.

The purpose of this study was to evaluate whether any of the following factors are related to knee anterior laxity in healthy sportswomen: anthropometric characteristics, lower limb alignment characteristics, hormone-related factors and sport history. Six hundred and sixteen sportswomen were tested in the pre-season. The data have been analysed using linear regression for possible association of knee anterior laxity with other variables. Univariate linear regression indicated a positive association of knee anterior laxity with knee extension and navicular drop and a negative association with body height. Multivariate linear regression analysis showed statistically significant associations between knee anterior laxity and the combination of passive knee extension and the chosen sport (R(2)=0.089; p<0.05). The combination of passive knee extension and sport type was found to be related to the amount of knee anterior laxity, although the association was weak with this combination of factors able to explain only about 9% of the variability in laxity. Knowing which factors influence the amount of knee anterior laxity will help us to better interpret the results of knee anterior laxity testing and help us to understand the possible role of knee anterior laxity as a risk factor for knee injury.

Thirty pre‐menopausal women aged 35–40 years were assessed with respect to dietary calcium intake, physical activity and other factors related to bone loss (by questionnaire); bone mass in the mid and distal femur measured by computerized tomography; and leg strength and muscle size. Cortical thickness at mid‐femur was negatively associated with breast‐feeding (r=‐0.40). Bone mass in the distal femur was negatively associated with age (r=‐0.46) and positively associated with activity (r=0.44) and leg strength (r=0.42). There was no association of bone mass at either site with current dietary calcium intake (range 198–1511 mg/day), nor with body mass index (BMI), hand‐grip strength, parity, oral contraceptive use, smoking, or alcohol intake. Thus, in older pre‐menopausal women, activity apparently helps to maintain bone mass at the distal femur, a site of high trabecular bone content, while current dietary‐calcium intake has no effect on bone mass in the femur. Activity was most strongly associated with bone mass in the distal femur when it was defined as the total number of hours spent standing or moving (i.e. other than sitting or lying down), regardless of the intensity of activity. The strong negative association between bone mass in the distal femur and age in older pre‐menopausal women is of concern in relation to long‐term risk of osteoporotic related fracture, suggesting that factors relating to bone loss in this age‐group should be studied longitudinally. The apparent loss of cortical bone in breast‐feeders warrants further investigation.

The purpose of this study was to investigate if knee anterior laxity, measured with an arthrometer, is a risk factor for traumatic knee injury in sportswomen. To allow a more complete analysis, other, easily measured variables such as anthropometry, lower leg characteristics, sport exposure and menstrual cycle characteristics were also evaluated as possible risk factors. Subjects were Slovenian sportswomen aged between 11 and 41 years participating in basketball, team handball and volleyball (N = 540). Sportswomen were tested in the pre-season and followed for one season. The data collection included: written informed consent, background questionnaire, anthropometric tests, leg dominance assessment, navicular drop test (measurement of foot pronation), passive knee extension assessment and measurement of knee anterior laxity with a KT arthrometer. Several sets of data analysis were performed including logistic regression analysis in order to build a model for predicting traumatic knee injury among sportswomen. Height and average hours of training per week were found to differ significantly (P < 0.05) between injured and uninjured sportswomen. More sportswomen injured their non-dominant leg. Traumatic knee injuries among Slovenian sportswomen participating in basketball, team handball and volleyball are associated with higher amounts of training, greater body height and greater knee anterior laxity. Only 1% of the variability in traumatic knee injuries among sportswomen were explained with those variables suggesting that there are many other variables associated with traumatic knee injuries among sportswomen than were tested in this study.

A fly-wheel ergometer (FWE) offering resistance training of the knee extensors has been designed for space travel and found to be effective during bed rest. The possibility exists that this device is also effective in training the knee extensors after knee injury. The purpose of this study was to compare the FWE to standard knee extensor training equipment for their effects on individuals with a history of knee injury, a group who commonly suffer from weakness of the knee extensors that effects their function. Twenty-nine subjects completed the study, which included tests of knee self-assessment, knee extensor static and dynamic muscle strength, size and neural activation as well as single leg power output, standing balance and vertical jump performance. Both groups showed statistically significant (P < 0.05) improvements in these variables over the 3-month training period but no differences were noted between the groups. The FWE appears to be as effective as standard resistance training equipment for improving knee extensor muscle group size and performance after knee injury.

Decreased steadiness of muscle force may be associated with ageing and could be a cause of falls in older people. We studied this in isometric and anisometric quadriceps contractions in healthy young and older people. The older group contained people with and without a history of medically unexplained falls. Forty-four young (aged 18-40 years) and 78 older (aged > 70 years) subjects participated. In the latter group 34 people had a history of falling (fallers) and 44 did not (non-fallers). Isometric steadiness was measured by the coefficient of variation (CoV) of force at 10, 25 and 50% maximal voluntary force (MVC). Anisometric steadiness was measured by the SD of acceleration during concentric and eccentric contractions against two external loads (1 and 5 kg). There was an overall trend for the younger subjects to be most steady and the fallers the least but the differences were not consistently significant. Isometric steadiness was unaffected by force in all groups. The fallers were less steady (P < 0.001) than both the young and non-fallers, who had similar values. During anisometric contractions, steadiness was similar with both external loads and types of contraction in all groups. During dynamic contractions the older subjects were less steady (P < 0.002). Only eccentric contractions distinguished between the two older groups, with the fallers being less steady by 31% (P = 0.013). These data indicate ageing per se is associated with decreased anisometric, but not isometric, steadiness. Greater unsteadiness during eccentric contractions in the fallers could be an important mechanism of medically unexplained falls.

Risk factors for medically unexplained falls may include reduced muscle power, strength and asymmetry in the lower limbs. Conflicting reports exist about strength and there is little information about power and symmetry. Forty-four healthy young people (29.3 +/- 0.6 years), 44 older non-fallers (75.9 +/- 0.6 years), and 34 older fallers (76.4 +/- 0.8 years) were studied. Isometric, concentric and eccentric strength of the knee and ankle muscles and leg extension power were measured bilaterally. The younger group was stronger in all muscles and types of contraction than both older groups (P < 0.02-0.0001). Strength differences between the older groups occasionally reached significance in individual muscles and types of contraction but overall the fallers had 85% of the strength and 79% of the power of the non-fallers (P < 0.001). Young subjects generated more power than both older groups (P < 0.0001) and the fallers generated less than the non-fallers (P = 0.03). Strength symmetry showed an inconsistent age effect in some muscles and some contraction types. This was similar overall in the two older groups. Both older groups had greater asymmetry in power than the young (P < 0.02-0.004). Power asymmetry tended to be greater in the fallers than the non-fallers but this did not reach significance. These data do not support the suggestion that asymmetry of strength and power are associated with either increasing age or fall history. Power output showed clear differences between age groups and fall status and appears to be the most relevant measurement of fall risk and highlights the cumulative effects on function of small changes in strength in individual muscle groups.

There are conflicting reports of the effects of hormone replacement therapy (HRT) on strength preservation in postmenopausal women, while any effect on power output has received little attention. Decreased steadiness of force generation has been reported in older muscles and may be related to the hormonal changes associated with the menopause, but the effect of HRT has not been investigated. We have studied the effect of HRT on strength, power output and isometric force steadiness in healthy women. Sixteen young (aged 27.4 +/- 1.4 years, mean +/- SEM) and 29 postmenopausal women were studied. Fifteen of the latter were taking HRT (68.1 +/- 1.4 years, HRT+) and 14 (70.5 +/- 1.5 years, HRT-) had never done so. During isometric quadriceps contractions the force steadiness (coefficient of variation of force) was measured at 10, 25, 50 and 100% maximum voluntary contraction (MVC). The average power generated by an explosive leg extension was recorded. The HRT- group generated less power (110.2 +/- 7.2 W) than both the HRT+ (136.5 +/- 10.9 W, P = 0.027) and young (136.2 +/- 5.8 W, P = 0.027) subjects. Power output was similar in the HRT+ and younger subjects. The HRT- subjects were weaker than the younger ones (241.3 +/- 14.0 N vs. 297.6 +/- 13 N, P = 0.006). The strength of the HRT+ group (255.5 +/- 14 N) was not significantly different to the other two groups. There was no difference in steadiness between the three groups at any of the force levels. HRT appears to maintain power output to a greater extent than isometric strength in postmenopausal women. There was no evidence for an effect of either age or HRT on isometric steadiness in the quadriceps.