Time-course of thigh muscle contraction-induced blood flow magnitude in amputated lower limb with prosthesis during dynamic knee extensions: A case study

Abstract

Background:The increase in exercising leg blood flow (LBF) is directly proportional to the workload performed, in relation to the interplay between cardiovascular regulation and muscle energy metabolism. However, little information is available on exercise LBF in thigh muscle contractions in amputated lower legs (ALL) via the stump fitting prosthesis. Case presentation: A 79-year-old male patient performed 3-min one-legged repeat/dynamic knee extensor exercise at a target muscle contraction frequency (1-s thigh muscle contraction and 1-s relaxation, 90 repetitions) on each leg (left ALL as trans-tibial amputation using a patellar tendon-bearing prosthesis and right non-ALL) at six different contraction intensities. Simultaneous measurement of blood velocity/flow (Doppler ultrasound) in the femoral artery, blood pressure, leg vascular conductance and muscle strength were performed at pre-exercise, during 3-min exercise and 5-min recovery. There was a 12% reduction in the maximum thigh circumference in the ALL compared to non-ALL. LBF was lower in the ALL than non-ALL at pre-exercise and during exercise. In non-ALL, there was a good positive linear relationship (r=0.922, P<0.01) between mean peak muscle strength and mean exercising LBF during 30-s steady-state before the end of exercise, but the same relationship was not seen (r=0.220, P=ns) in the ALL. Conclusions: The present clinical intervention study showed no significant thigh LBF increase in the ALL with incremental workload (peak muscle strength). This might be due to a mismatch of the workloaddependent LBF increase in the disused and/or atrophic thigh muscle-resection stump of the ALL compared to non-ALL, which in ALL may be due to remaining muscle contractile effort with a reduced arterial inflow and/or lack of venous return in relation to the arteriovenous pressure gradient and/or hydrostatic pressure through the lower leg.

Voluntary Thigh Muscle Strength with Resection Stump-Dependent Blood Flow and Vasodilation in an Amputated Lower Leg with Total Surface Bearing Prosthesis during Dynamic Knee Extensor: A Case Trial

“…The present case may potentially indicate that muscle strength dependent-LBF and/or -vasodilation was also seen in a "below-knee amputation of the AL using TSB prosthesis" as well as in the healthy leg (non-AL) in repeated dynamic knee extensor exercise. This work is series in our previous case, which involved determination of the time course of magnitude in whole LBF in the exercising thigh stump using a PTB [27]. These findings are discussed in the following section.…”

“…We reported recently on an interventional study with another amputee who performed knee extensor exercise using the same protocol as the present study [27]. The previous finding included determination of validated measurements of exercising thigh-stump LBF and its time-course in the amputated leg with PTB prosthesis using Doppler ultrasound.…”

“…The peak muscle contraction strength (in kg) of every knee extensor kick was evaluated using a strain gauge and amplifier [27]. The rubber band was tied in a loop, enclosing the ankle, with a sensor fixed in the chair strut connected to the strain gauge with amplifier (Meiko Co. Ltd, Tokyo, Japan), and values were recorded continuously on a computer using a PowerLab data acquisition system (Figure 1).…”

“…We speculated that this discrepancy between the AL and non-AL may be due to a mismatch of the workload-dependent LBF increase in the disused and/or atrophic thigh muscle-resection stump of the AL compared with the non-AL, which in the AL may be due to the remaining muscle contractile effort with a reduced arterial inflow and/or lack of venous return in relation to the arteriovenous pressure gradient and/or hydrostatic pressure through the lower leg [27].…”

“…Pulsatile blood velocity profile in the conduit artery at systole and diastole may be detected at rest, synchronized with the cardiac beat and blood pressure [18] [19] [20]. Based on this technique, rapid changes in blood velocity can be measured with muscle contraction and relaxation and/or cardiac beat-to-beat in different states of exercise, muscle contraction time/frequency and workload, and in relation to vasodilatation/vasoconstriction [21] Using the above-mentioned Doppler technique, we have recently reported a clinical intervention for LBF magnitude in an amputated lower leg with a patella tendon bearing (PTB) prosthesis during unilateral dynamic knee extensor exercise at incremental exercise intensity [27]. This initial brief report involved an unexpected result with no significant thigh LBF increases in the AL using a PTB prosthesis during incremental absolute/relative peak muscle contraction (workload), although workload-dependent LBF increases were seen in the non-AL, which was in agreement with previous findings.…”