clinical trial, orthopaedic leg trolley, walking aids

Clinical Trial

A comparison of energy expenditure when walking with crutches and when walking with the trolley by Paul Roberts and Susan Carnes at the Royal Orthopaedic Hospital, Birmingham.

Sixteen fit volunteers with an age range of 21 to 40 years (mean 25), familiarised themselves with walking non-weight bearing on one limb on a treadmill using axillary crutches, elbow crutches and the orthopaedic scooter. Each volunteer then walked at three kilometres an hour for five minutes on each device in random order. During this period their gas exchange was monitored using an Oxycon-4 gas analyser and they were asked to give their rating of perceived exertion.(RPE) each minute.

The RPE is a score determined by how hard the subject finds the exercise; a score of seven represents 'very, very light' work and 19 'very, very hard' work (Borg and Noble 1974)

Results

The energy expenditure and the mean RPE for normal walking and walking using each device are presented in Tables 1 and 2. Using the paired t-test there was a highly significant difference in both the energy consumption and the mean RPE between using the orthopaedic scooter and either type of crutch (p=< 0.0001). The scooter required 25% less energy expenditure than crutches.

Method of Walking	Mean expenditure Kcal/Kg/hr (s.d.)	% of normal expenditure

Normal	2.8 (0.54)	100
Orthopaedic scooter	4.8 (1.01)	171
Elbow crutches	6.6 (1.63)	236
Axillary crutches	6.5 (1.23)	232

Table 1. Energy expenditure whilst walking

Method of Walking	Mean score (s.d.)

Normal	6.7 (0.6)
Orthopaedic scooter	10.3 (1.3)
Elbow crutches	13.0 (1.8)
Axillary crutches	12.6 (1.6)

Table 2. Rating of perceived exertion (Borg and Noble 1974)

There was no significant difference in energy consumption (p = 0.44), or mean RPE (p=0.31) between the two types of crutch.

Discussion

Beath, Bahrke and Balke (1974) showed that axillary and elbow crutches required similar energy expenditures. Our study confirms this and demonstrates that both the actual and the perceived work of walking are significantly reduced using the orthopaedic scooter. It also has other advantages: the hands are free for other uses, the injured foot is elevated and not dependent as it is with crutches, body-weight is distributed through both legs and the proximal muscles of the injured leg are used extensively which may help to preserve muscle bulk and bone strength. The scooter is particularly valuable in the rehabilitation of patients with ankle and foot injuries who must remain non-weight-bearing.

It has also been used successfully in the treatment of patients with diabetic plantar ulcers as an alternative to bed-rest or contact plasters (F. I. Tovey, personal communication).

References

Borg GAV, Noble BJ. Perceived exertion. In: Wilmore JH, ed. Exercise and sport sciences reviews. Vol 2. New York: Academic Press, 1974:131-53.

McBeath AA, Bahrke M, Balke B. Efficiency of assisted ambulation determined by oxygen consumption measurement.
J Bone Joint Surg [Am] 1974. 56-A:994- 1000.

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