Hooshang Izadi

Stochastic frontier estimation of a CES cost function: the case of higher education in Britain

Abstract Many estimates exist in the literature of multi-product cost functions estimated across a sample of institutions of higher education. Typically these have not employed the appropriate frontier estimation techniques. The cost functions usually estimated — such as the constant elasticity of substitution (CES) function — are highly non-linear, and the standard software packages do not allow stochastic frontier estimation in such cases. We derive and maximise the likelihood function associated with this problem, and hence construct measures of economies of scale and scope which obtain in British higher education. We use the half-normal residuals generated by the stochastic frontier estimation to construct measures of technical efficiency for each university in our sample.

Treadmill training for individuals with multiple sclerosis: a pilot randomised trial

This pilot study investigated whether 4 weeks of aerobic treadmill training in individuals with multiple sclerosis (MS) improved mobility and reduced fatigue. Individuals with MS were recruited to this prospective, randomised controlled trial. Individuals were assessed at baseline, week 7 and 12 with a 10 metre timed walk, a 2 minute walk, the Rivermead Mobility Index, and the Fatigue Severity Scale. After a pre-assessment familiarisation session and a baseline assessment, individuals were randomly allocated to an initial intervention or delayed intervention group. Treadmill training consisted of 4 weeks of supervised aerobic exercise delivered weeks 3–6 in the immediate group and 8–11 in the delayed group. Of the initial 19 recruits, 16 individuals completed the study. There was a significant difference in walking endurance between the delayed and immediate groups at baseline (p<0.05). On reassessment in week 7, decreases in 10 metre walk time were found in both groups, which was significant in the immediate group (p<0.05). The 2 minute walk distance significantly increased in both groups (p<0.05). In the training group, reassessed at week 12 after training ceased, there was a return towards baseline scores. No significant changes in fatigue scores were found. This study showed that in individuals with MS, aerobic treadmill training is feasible and well tolerated. Walking speed and endurance increased following training with no increase in reported fatigue. Detraining occurred in the period following training. A larger randomised clinical trial is warranted.

Can aerobic treadmill training reduce the effort of walking and fatigue in people with multiple sclerosis: a pilot study

Impaired mobility in multiple sclerosis (MS) is associated with high-energy costs and effort when walking, gait abnormalities, poor endurance and fatigue. This repeated measures trial with blinded assessments investigated the effect of treadmill walking at an aerobic training intensity in 16 adults with MS. The intervention consisted of 12 sessions of up to 30 minutes treadmill training (TT), at 55–85% of age-predicted maximum heart rate. The primary outcome measure was walking effort, measured by oxygen consumption (mL/kg per metre), during treadmill walking at comfortable walking speed (CWS). Associated changes in gait parameters using the ‘Gait-Rite’ mat, 10-m time and 2-minute distance, and Fatigue Severity Scale were examined. Following training, oxygen consumption decreased at rest (P = 0.008), CWS increased (P = 0.002), and 10-m times (P = 0.032) and walking endurance (P = 0.020) increased. At increased CWS, oxygen consumption decreased (P = 0.020), with a decreased time spent in stance in the weaker leg (P = 0.034), and a greater stride distance with the stronger leg (P = 0.044). Reported fatigue levels remained the same. Aerobic TT presents the opportunity to alter a motor skill and reduce the effort of walking, whilst addressing cardiovascular de-conditioning, thereby, potentially reducing effort and fatigue for some people with MS.

An Integrated Motor Imagery Program to Improve Functional Task Performance in Neurorehabilitation: A Single-Blind Randomized Controlled Trial

OBJECTIVE To investigate the feasibility of a motor imagery program integrated into physiotherapy and occupational therapy. DESIGN A parallel-group, phase II, assessor-blind randomized controlled trial comparing motor imagery embedded in usual therapy with usual therapy only. SETTING A neurologic rehabilitation center (Oxford, United Kingdom). PARTICIPANTS Inpatients and outpatients diagnosed with stroke, brain injury, or multiple sclerosis, participating in a rehabilitation program with sufficient language skills to undertake the intervention were recruited (N=30) and assessed at baseline, after 6 weeks (postintervention), and after 12 weeks (follow-up). INTERVENTIONS A motor imagery strategy was developed that could be integrated into usual therapy, tailored to individual goals, and used for any activity. The control group received standard care. MAIN OUTCOME MEASURES Goal attainment scaling was used as the primary outcome measure. Other measures included the Barthel activities of daily living index and the Rivermead Mobility Index. RESULTS Compliance with advised treatment was poor in 85% of the therapists and in 72% of the patients. Goal attainment scaling scores significantly improved at postintervention and follow-up (F(2,27)=45.159; P<.001), but no significant difference was observed between the groups over time (F(1,28)=.039; P=.845). CONCLUSIONS Therapist and patient compliance with performing the intervention was low, restricting the conclusions regarding the effectiveness of the integrated motor imagery program. Future studies will need to explore barriers and facilitators to uptake of this intervention in clinical practice. Trial recruitment and retention were good. The study demonstrated that imagery could be successfully integrated into usual therapy and tailored for a wide range of functional activities.

A pilot randomised controlled trial of a home-based exercise programme aimed at improving endurance and function in adults with neuromuscular disorders

Aim: To investigate the feasibility and effect of a home-based exercise programme on walking endurance, muscle strength, fatigue and function in people with neuromuscular disorders (NMDs). Methods: 20 adults with NMDs recruited to a control (n = 11) or exercise (n = 9) group were assessed by blinded assessors at baseline and at week 8. Walking and strengthening exercises were given to the exercise group in an 8-week home exercise programme. A 2-min walk distance was the main outcome measurement; isometric muscle strength, fatigue and function were secondary measurements. Results: 2-min walk distances were not found to change in either group (p>0.05; control: mean 14.50 (SD 22.06) m; exercise: mean 2.88 (SD 20.08) m), and no difference was observed in the change scores between groups (p>0.05). Leg muscle strength increased in the exercise group (p<0.05) but not in the control group (p>0.05). Significance was reached between the groups with respect to the difference in change in muscle strength scores in the right quadriceps (p<0.05; control: mean −2.82 (SD 4.87) kg; exercise: mean −7.08 (SD 2.82) kg). No change was observed in fatigue or function scores (p<0.05). Conclusions: A home-based approach aimed at improving endurance in adults with NMDs is feasible and further investigation on a larger sample is warranted.

Fast walking under cognitive-motor interference conditions in chronic stroke

Gait in stroke patients is often characterised by slower speeds, which may be exacerbated by situations that combine gait with a cognitive task, leading to difficulties with everyday activities. Interaction between cognitive task performance and gait speed may differ according to walking intensity. This study examines the effects of two cognitive tasks on gait at preferred walking pace, and at a faster pace, using dual-task methodology. 21 chronic stroke patients and 10 age-matched control subjects performed 2 single motor tasks (walking at preferred and at fast pace around a walkway), and two cognitive tasks (serial subtractions of 3s and a visual-spatial decision task) under single- and dual-task conditions (cognitive-motor interference) in a randomised order. Cognitive task score and gait speed were measured. The healthy control group showed no effects of CMI. The stroke group decreased their walking speed whilst concurrently performing serial 3s during both preferred and fast walking trials and made more mistakes in the visuo-spatial task during fast walking. There was no effect of walking on the serial 3 performance. The findings show that in stroke patients, during walking whilst concurrently counting backwards in 3s the cognitive task appeared to take priority over maintenance of walking speed. During fast walking whilst concurrently performing a visuo-spatial imagery task, they appeared to favour walking. This may indicate that people spontaneously favour one activity over the other, which has implications for gait rehabilitation.

Weekly exercise does not improve fatigue levels in Parkinson's disease.

Fatigue is one of the most disabling non‐motor symptoms for people with Parkinsons disease. Exercise may modify fatigue. This study examines prescribed exercise effects on physical activity levels, well‐being, and fatigue in Parkinsons disease.

Supported community exercise in people with long-term neurological conditions: a phase II randomized controlled trial

Objective: Adults with long-term neurological conditions have low levels of participation in physical activities and report many barriers to participation in exercise. This study examines the feasibility and safety of supporting community exercise for people with long-term neurological conditions using a physical activity support system. Design: A phase II randomized controlled trial using computer-generated block randomization, allocation concealment and single blind outcome assessment. Setting: Oxfordshire and Birmingham community Inclusive Fitness Initiative gyms. Subjects: Patients with a long-term neurological condition. Interventions: The intervention group (n = 51) received a 12-week, supported exercise programme. The control group (n = 48) participants received standard care for 12 weeks and were then offered the intervention. Main measures: Physical activity, adherence to exercise, measures of mobility, health and well-being. Results: Forty-eight patients (n = 51) completed the intervention, achieving 14 gym attendances (range 0–39) over the 12 weeks. Overall activity did not increase as measured by the Physical Activity Scale for the Elderly (change score mean 14.31; 95% confidence interval (CI) −8.27 to 36.89) and there were no statistically significant changes in body function and health and well-being measures. Conclusions: People with long-term neurological conditions can safely exercise in community gyms when supported and achieve similar attendance to standard exercise referral schemes, but may reduce other life activities in order to participate at a gym.

Delayed recovery of leg fatigue symptoms following a maximal exercise session in people with multiple sclerosis.

Background. Fatigue is a chronic symptom for people with multiple sclerosis (PwMS). Objective. Symptoms of fatigue were investigated during and following a single exercise session. Methods. In all, 58 PwMS and 15 healthy, low-active controls performed a cycle ergometer incremental exercise test to voluntary exhaustion. Physiological intensity (expired air and heart rate), perceived breathlessness, and leg fatigue (Rating of Perceived Exertion [RPE] CR-10 Scale) were measured during and for 10 minutes following exercise. Measures of baseline disability (Barthel Index), activity (Physical Activity Scale for the Elderly), vitality (Subjective Vitality Scale), and general fatigue (Fatigue Severity Scale [FSS]) were recorded. Results. PwMS had reduced exercise capacity (P = .00 to .01), but sensations of breathlessness and leg fatigue were the same at voluntary exercise termination in both groups (P = .09). PwMS with fatigue (FSS ≥ 4) exhibited reduced exercise capacity (P = .03 to .05) but reached the same physiological intensity, breathlessness, and leg fatigue symptoms at test termination as nonfatigued peers (P = .16 to .59). During recovery, there was no difference in observed means between groups, except for leg RPE, which was higher in the MS group (P = .047) and higher at 3 and 5 minutes after exercise in the fatigued MS group (P = .02). Physiological markers and breathlessness recovered at the same rate in both groups (P = .33 to .67). Conclusion. Monitoring leg fatigue symptoms during and through recovery from physical activities may help guide participation in physical activities for PwMS, particularly in people managing high levels of fatigue.

Mental techniques during manual stretching in spasticity — a pilot randomized controlled trial

Objective: To evaluate the feasibility and effects of using motor imagery during therapeutic stretching in individuals with spasticity. Design: Randomized single-blind controlled pilot trial. Setting: Chronic day care unit, neurological rehabilitation unit and in the community. Subjects: Eleven individuals with spasticity in the arm requiring stretching as part of their normal routine. Interventions: In addition to their normal stretching routine, subjects in the experimental group received motor imagery during their stretches (n = 6). The control group received progressive muscle relaxation during their stretches (n = 5). The dose varied between 8 and 56 sessions over eight weeks. Main measures: Resistance to passive movement, measured with a torque transducer, passive range of movement, measured with an electro-goniometer, Modified Ashworth Scale (MAS) and level of discomfort during the MAS were assessed at baseline and after eight weeks by an independent assessor. These measures were recorded before and after a stretch intervention on both assessments. Results: Participants, therapists and carers tolerated the techniques well. Compliance was variable and adherence was good. Mixed ANOVA showed no difference over time and no difference between the motor imagery and progressive muscle relaxation group on the primary and secondary outcome measures (P>0.05). Conclusions: It is feasible to use motor imagery during therapeutic stretching. Statistical power was low due to the large variability in the population and the small sample size. Post-hoc sample size calculation suggests that future studies of this subject should include at least 54 participants per group. Further research is warranted.