Self-efficacy, imagery use, and adherence during injury rehabilitation.

Previous observational studies examining imagery, self-efficacy, and adherence during injury rehabilitation have been cross-sectional and thus have not provided a clear representation of what occurs over the course of the rehabilitation period. The objectives of this research were (1) to examine the temporal patterns of imagery, self-efficacy, and rehabilitation adherence during an 8-week rehabilitation program and (2) to identify the time-order relationships between imagery, self-efficacy, and adherence. The design of the study was prospective and observational. 90 injured people (n=57 males; n=33 females) aged 18-78 years attending an injury rehabilitation clinic participated. The main outcome measures were imagery (cognitive, motivational, and healing), self-efficacy (task and coping), and rehabilitation adherence (duration, quality, and frequency). Results indicated that task efficacy, imagery use, and adherence levels remained stable, while coping efficacy declined over time. During the course of rehabilitation, moderate to strong reciprocal relationships existed between self-efficacy and adherence to rehabilitation. Weak to moderate relationships were found between imagery use and rehabilitation adherence. The results of this study can be used to inform the development of interventions steeped in self-efficacy and imagery aimed at improving rehabilitation adherence and treatment outcome.

Hip abduction-adduction strength and one-leg hop tests: test-retest reliability and relationship to function in elite ice hockey players.

STUDY DESIGN: Single group, test-retest. OBJECTIVES: To determine: (1) hip abduction and adduction torques during concentric and eccentric muscle actions, (2) medial and lateral one-leg hop distances, (3) the test-retest reliability of these measurements, and (4) the relationship between isokinetic measures of hip muscle strength and hop distances in elite ice hockey players. BACKGROUND: The skating motion used in ice hockey requires strong contractions of the hip and knee musculature. However, baseline scores for hip strength and hop distances, their test-retest reliability, and measures of the extent to which these tests are related for this population are not available. METHODS AND MEASURES: The dominant leg of 27 men (mean age 20 +/- 3 yrs) was tested on 2 occasions. Hip abduction and adduction movements were completed at 60 degrees.s(-1) angular velocity, with the subject lying on the non-test side and the test leg moving vertically in the subject's coronal plane. One-leg hops requiring jumping from and landing on the same leg without losing balance were completed in the medial and lateral directions. RESULTS: Hip adduction torques were significantly greater than abduction torques during both concentric and eccentric muscle actions, while no significant difference was observed between medial and lateral hop distances. Although hop test scores produced excellent ICCs (> 0.75) when determined using scores on 1 occasion, torques needed to be averaged over 2 test occasions to reach this level. Correlations between the strength and hop tests ranged from slight to low (r = -0.26 to 0.27) and were characterized by wide 95% confidence intervals (-0.54 to 0.61). CONCLUSIONS: Isokinetic tests of hip abduction and adduction did not provide a strong indication of performance during sideways hop tests. Although isokinetic tests can provide a measure of muscular strength under specific test conditions, they should not be relied upon as a primary indicator of functional abilities or readiness to return to activity.

Asymmetrical strength changes and injuries in athletes training on a small radius curve indoor track.

OBJECTIVES: 1) To evaluate strength changes in the hindfoot invertor and evertor muscle groups of athletes training and competing primarily in the counterclockwise direction on an indoor, unbanked track, and 2) to observe injuries occurring in these same runners over the course of an indoor season. DESIGN: Prospective observational study. SETTING: Fowler-Kennedy Sport Medicine Clinic, The University of Western Ontario, London, Ontario. PARTICIPANTS: A convenience sample of 25 intercollegiate, long sprinters (200-600 m) and middle distance runners (800-3,000 m) competing and training with the 1995-1996 University of Western Ontario Track and Field team. MAIN OUTCOME MEASURES: A standardized protocol using the Cybex 6000 isokinetic dynamometer was used to measure peak torques of the hindfoot invertor and evertor muscle groups of both limbs using concentric and eccentric contractions performed at angular velocities of 60, 120, and 300 degrees/sec. Changes in peak torques between the preseason and postseason values were calculated and compared using a repeated measures analysis of variance test. Injury reports were collected by student athletic trainers and in the Sport Medicine and Physiotherapy clinic. RESULTS: Primary analysis indicated that the left (inside limb) invertors increased in strength significantly more than the right (outside limb) invertors (p = 0.01), while the right evertors increased in strength significantly more than the left evertors (p = 0.04). A high incidence of lower extremity injury (68%) occurred in this sample of runners, corresponding to an injury rate of 0.75 injuries per 100 person-hours of sport exposure. Although sample size was limited, secondary analysis indicated that strength changes were not significantly different for injured (n = 17) and uninjured (n = 8) runners (p > 0.05). CONCLUSIONS: The observed small, but statistically significant, asymmetrical changes in strength of the hindfoot invertor and evertor muscle groups can best be described as a training effect. Altered biomechanics proposed to occur in the stance foot while running on the curve of the track are discussed in relation to the observed strength imbalance. A causal link between strength changes and lower extremity injuries cannot be inferred from this study, but suggestions for further research are made.

To pay or not to pay? A decision and cost-utility analysis of angiotensin-converting-enzyme inhibitor therapy for diabetic nephropathy.

BACKGROUND: Angiotensin-converting-enzyme (ACE) inhibitor therapy can significantly delay the progression of diabetic nephropathy to end-stage renal failure (ESRF). The main obstacle to successful compliance with this therapy is the cost to the patients. The authors performed a cost-utility analysis from the government's perspective to see whether the province or territory should pay for ACE inhibitors for type I diabetic nephropathy on the assumption that cost is a major barrier to compliance with this important therapy. METHODS: A decision analysis tree was created to demonstrate the progression of type I diabetes with macroproteinuria from the point of prescription of ACE inhibitor therapy through to ESRF management, with a 21-year follow-up. Drug compliance, cost of ESRF treatment, utilities and survival data were taken from Canadian sources and used in the cost-utility analysis. One-way and two-way sensitivity analyses were performed to test the robustness of the findings. RESULTS: Compared with a no-payment strategy, provincial payment of ACE inhibitor therapy was found to be highly cost-effective: it resulted in an increase of 0.147 in the number of quality-adjusted life-years (QALYs) and an annual cost savings of $849 per patient. The sensitivity analyses indicated that the cost-effectiveness depends on compliance, effect of benefit and the cost of drug therapy. Changes in the compliance rate from 67% to 51% could result in a swing in cost-effectiveness from a savings of $899 to an expenditure of more than $1 million per additional QALY. A 50% reduction in the cost of ACE inhibitors would result in a cost savings of $299 per additional QALY with compliance rates as low as 58% in the provincial payment strategy. INTERPRETATION: Provincial coverage of ACE inhibitor therapy for type I diabetes with macroproteinuria improves patient outcomes, with a decrease in cost for ESRF services.

Does strengthening the abdominal muscles prevent low back pain--a randomized controlled trial.

OBJECTIVE: To investigate the effects of abdominal muscle strengthening exercise on low back pain (LBP) risk reduction. METHODS: We compared the effects of abdominal muscle strength (AMS) exercise and back education with back education only on 402 asymptomatic subjects with weak AMS. The primary outcome was the percentage of subjects with at least one episode of LBP at 24 months. A diary was used to monitor compliance. RESULTS: There were no statistically significant differences between experimental (E) and control (C) subjects at 24 months for LBP episodes (E: 34.7%, C: 30.4%; C-E = 4.2%, P2 = 0.481; 95% CI -16.1%, 7.6%). The LBP episodes were also not statistically significantly different at 6 months (E: 13.2%, C: 16.1%; C-E: 2.9%, P2 = 0.493; 95% CI -5.3%, 11.0%) or at 12 months (E: 24.8%, C: 23.6%; C-E = -1.2%, P2 = 0.818; 95% CI -11.6%, 9.2%). Adjusting the data for strata and baseline AMS did not alter the findings. Imputed results for LBP episodes at 6 months (C-E: 4.8%, P2 = 0.191; 95% CI -2.4%, 12.0%), 12 months (C-E: -1.0%, P2 = 0.821; 95% CI -9.5%, 7.6%), and 24 months (C-E: -3.3%, P2 = 0.483; 95% CI -12.6%, 5.9%) were also not statistically significantly different. CONCLUSION: Back education and abdominal exercise instructions are similar to back education alone. There were no group differences in LBP episodes, possibly due to noncompliance with the exercise program. While the estimated benefit of 2.9% at 6 months from the complete data and 4.8% from the imputed data were not statistically significant, a larger study or future metaanalyses may be needed to confirm whether there is a clinical benefit or whether these results should be considered a chance finding.

Comparisons of weight-bearing and non-weight-bearing tests of knee proprioception performed by patients with patello-femoral pain syndrome and asymptomatic individuals.

OBJECTIVE: To compare non-weight-bearing (sitting) and weight-bearing (standing, with approximately 95% of body weight on the test leg) tests of knee proprioception performed by patients with patello-femoral pain syndrome (PFPS) and asymptomatic individuals. DESIGN: A repeated measures design, repeated on two occasions. SETTING: Athletic injuries clinic. PARTICIPANTS: Seven men and 17 women with PFPS, and age- and sex-matched asymptomatic individuals. INTERVENTIONS: With their eyes closed, subjects extended their knee in sitting, or flexed their knees in standing, attempting to replicate target angles (15 degrees, 30 degrees, 45 degrees, and 60 degrees knee flexion) measured using an electrogoniometer. MAIN OUTCOME MEASURE: Observed angle of knee flexion during joint angle replication tests. RESULTS: Test-retest reliability coefficients (0.17-0.79) and between-session measurement error (+/-2.0 degrees to +/-6.4 degrees) varied widely. There was a tendency for reliability coefficients to be greater and between-session measurement error to be lower, for PFPS subjects, and for sitting tests. No significant differences were observed between the scores of the PFPS and asymptomatic subjects, at any of the four target knee angles. CONCLUSIONS: Scores in sitting should not be compared with those in standing. Clinically, the low reliability coefficients, large between-session measurement error, and finding of no statistically significant difference between PFPS and asymptomatic subjects suggest that the diagnostic value of the proprioceptive tests used is questionable. Further research is required to develop more precise tests of knee proprioception and to determine if the present results are applicable to other pathologies.

Postoperative eccentric and concentric isokinetic strength for the shoulder rotators in the scapular and neutral planes.

Considerable variability exists for isokinetic testing of the shoulder rotators, leaving the clinician in a quandry concerning the most appropriate method for patient evaluation. The purpose of this study was to evaluate concentric and eccentric rotational strength in the scapular and neutral planes for the surgical and nonsurgical shoulders. Fifteen males consented to be tested during a 90-minute isokinetic session. Both shoulders for each patient were tested concentrically (240 degrees/sec) and eccentrically (120 degrees/sec) in the scapular and neutral planes. Patient positioning was maintained through the use of a goniometer, plumb line, and floor grid system. Following a warmup, five maximal effort reciprocal internal and external rotation concentric and eccentric contractions were evaluated using multiple two-way analyses of variance (shoulder x plane) with repeated measures. Results indicated no statistically significant differences between the surgical or nonsurgical shoulders for either concentric (p = .063-.247) or eccentric (p = .460-.840) modes, regardless of test plane. No statistically significant differences were observed eccentrically between test planes (p = .06-.470), but the scapular plane produced significantly higher (p = .005) peak torques concentrically. Generally, the external rotators were 53.0% (concentrically) and 63.0% (eccentrically) of the internal rotator strength for either shoulder. Clinically, concentric and eccentric testing of the postoperative shoulder patient can occur in either the scapular or the neutral plane. However, the scapular plane may be preferred since it is more functionally relevant and less injurious to the rotator cuff. A full, functional recovery may be expected for the rotator cuff repair patient.

Proprioception during manual aiming in individuals with shoulder instability and controls.

Recurrent glenohumeral joint instability is a common orthopaedic problem. One possible cause of this repeated instability is a lack of neuromuscular control and kinaesthetic sense of the glenohumeral joint. The purpose of this study was to determine whether there is a deficit in joint proprioception in subjects with recurrent anterior glenohumeral instability as compared with individuals with no previous shoulder pathology. Subjects were asked to generate pointing movements with their uninjured limb and to match this limb position with the injured limb. Movements of the pointing limb were measured with an optoelectric three-dimensional movement analysis system. These movements were performed in three conditions: 1) with full vision, 2) without vision, and 3) without vision with vibration to the posterior deltoid muscle. For the temporal and spatial measures, there were no significant differences between the control and shoulder instability groups. However, the kinematic data describing arm trajectory formation showed a performance decrement in the no vision with vibration condition for the subjects in the shoulder instability group, suggesting that they suffer from a proprioceptive deficit.