Stride Characteristics & Energy Expenditure in Unilateral Transtibial Amputees:A Comparison of SACH Foot & Jaipur Foot

ABSTRACT

The aim of the study was to determine the Stride characteristics and Energy expenditure in unilateral transtibial amputees comparing SACH foot & Jaipur foot in a sample of 31 unilateral transtibial amputees. The design of study was one group post study experimental design. The subjects were studied on two parameters i.e. Stride characteristics and Energy expenditure. These parameters were obtained using paper walkway & stop watch. The Energy expenditure obtained by calculating Physiological Cost Index(PCI) which is an empirical measure of the energy expenditure in gait was calculated from the net heart rate (walking heart rate- resting heart rate) divided by the walking speed(meter/minute)(McGregor,1980). The result were expressed as Mean± standard deviation and significant established at p≤0.05.The result of Stride characteristics revealed significant difference in Stride length (t-value=2.19, p-value=0.037) & Step length (t-value =4.08, p-value=0.000). In Cadence (t-value=1.63, p-value=0.114) & Velocity (t-value=1.65, p-value=0.109), there were no significant difference found. The result of physiological cost index (t-value=0.81, p-value=0.422) revealed that there is no significant difference either using SACH foot or Jaipur foot. The result of the study suggests that both the prosthetic feet are compatible to the unilateral transtibial amputees. The ultimate effect is to show the effect on Gait efficiency & energy expenditure in unilateral transtibial amputees using two biomechanical prosthetic feet which may help the clinician in selecting the foot during the prescription of unilateral transtibial amputees.

INTRODUCTION

Transtibial amputation is the amputation through a part of the tibia. It occurs due to many reasons but trauma is the major cause of amputation in the developing world. The transtibial amputation is the twice common than the transfemoral amputation1. The transtibial amputation is the most proximal level at which near normal level function can be expected for most of the amputees2, because of preserved anatomical knee joint consume much less energy (33% more than normal) than the transfemoral amputation(65% more than normal)3. To ensure the efficient ambulation, the prosthetic feet should mimic the function of the human foot throughout the gait cycle to the degree that this is feasible4. In India, two feet are commonly prescribed; SACH foot & Jaipur foot. The SACH foot was developed by University of California in 1957, which has no moving parts & provides movement by means of material used4. The Jaipur foot was developed by experts of SMS College & hospital, Jaipur, India by which patient can walk bare foot, can do the squatting & cross-legged sitting. This foot is water proof & can be used in field work.Jaipur foot also claims greater degree of movement due to its material used5.Torburn et.al6(1990) found no significant difference in walking speed, stride length &energy cost comparing SACH & other energy storing feet. In different study7(1995) he also found that there was no significant difference in energy consumption, walking speed, stride length & cadence comparing SACH, CC-II, Seattle, Quantum & flex feet7. A number of reviews8-19 have been done on stride characteristics & energy expenditure in various energy storing feet along with SACH foot, but no study has been conducted on the Stride characteristics & Energy expenditure in unilateral transtibial amputees comparing SACH foot & Jaipur foot.
The purpose of this study is to compare the Stride characteristics & Energy expenditure in unilateral transtibial amputees using SACH foot & Jaipur foot. The hypotheses of the present study are (1) The SACH foot will show better stride characteristics than SACH foot. (2)The SACH foot will result in more energy efficient gait than Jaipur foot. These parameters were obtained using paper walkway & stop watch. These tools were used because these are simple to use, reliable, quick & practical & easy to conduct in Indian clinical settings.Researchers21 have estimated good inter-rater reliability=.99) & test retest reliability (r=.89-.90) for the use of paper walkway to calculate the stride parameters.Astrand & Rodahl20 (1986) have shown the linear relationship between the heart rate & oxygen consumption is fundamental to the PCI & Rose et.al(1989)22 shown when calculating the PCI the resting heart rate is sensitive & must be measured with accuracy.

METHODOLOGY

A sample of convenience of 31 persons with transtibial amputee took part in this study. They were recruited by from Assessment clinic at Bhagwan Mahaveer Viklang Seva Samiti, New Delhi. Subjects who fulfilled the inclusion criteria were selected .The inclusion criteria for this study was Persons with unilateral transtibial amputation, Amputation secondary to Trauma, Age group between 20-40 years, Amputee using prosthesis for at least two years, Ideal stump, Normal range of motion of intact joint, good muscle strength of lower extremity. The subjects with bilateral Transtibial amputation, Contracture, Neuroma, Edema, Spur formation were excluded from the study. The mean age (years) of the subjects was 32.80+ 6.53.the mean of stump length of the subjects was 38.51%.the mean height (Centimeter) of the subjects was 161.63±4.42, the mean of weight of the subjects was 58.03±6.05 & the mean of BMI for all the subjects were 22.2±3.92, which showed that all the patient were under their average body mass index. All subjects had amputation secondary to trauma & all had been wearing prosthesis for at least two years. None of the subject had residual limb pain, swelling, neuroma & none showed major gait deviations. None of the subjects had y assistive devices. Residual limb length (percentage) for all subjects was at least 30%of the total sound limb length but did not exceed more than 52% i.e. 15% of the total body height. These criteria reflect the importance of maintaining the consistent limb length among subjects when evaluating Stride parameters & energy cost. The subject was initially fitted with prosthesis using the foot from earlier to minimize the adaptation time. The criteria of selecting foot were based on the height, weight of the subjects & the foot length of the non-amputated limb. The foot is tested was attached to the ankle & optimally aligned by the Prosthetist.Since it has been determined that the prosthetic alignment has an effect on gait symmetry, each foot was worn on the test prosthesis for three weeks. At the end of three weeks, the gait symmetry was analyzed using observational method. The stride parameters were measured using paper walkway of 10meter & stop watch. The 10 meter paper walkway was used in which initial & last 2 meter was marked for acceleration & deceleration. The time & steps within the 6 meter was used to calculate the stride parameters. To calculate the resting heart rate, initially the subject was given rest for ½ hour to bring the subject in resting position. Before the stride parameters collected, the resting heart rate was measured manually by measuring the pulse of the radial artery at the wrist in sitting position. After collection of stride parameters, the patient was asked to walk for 6 minutes and the end of 6 minutes the walking heart rate measured manually. After collecting the data of one prosthetic foot, another foot was attached to the test prosthesis with proper alignment done by the Prosthetist.Again the test prosthesis given to the subject for 3 weeks for adaptation.

RESULT

Statistics were performed using SPSS software version 10.5. A paired t-test was used to analyze the difference between SACH foot & Jaipur foot in terms of Stride characteristics and Energy expenditure. A significance level of p≤0.05 was fixed. The significant difference found only in stride length & step length of stride characteristics, & there were no significant difference found in cadence, Velocity as well as in energy expenditure using either SACH foot or Jaipur foot.

STRIDE CHARACTERISTICS
The result of stride characteristics in unilateral transtibial amputees using SACH foot & Jaipur foot revealed that; in cadence(Table-1 and figure-1) using SACH foot (mean=71.55±13.85) & Jaipur foot (Mean=81.90±15.81) did not show any significant difference(t-value=1.63,p-value=0.114), indicating both the feet are equally compatible in terms of cadence. In step length (Table-3 and figure-3) using SACH foot (mean=64.41±7.81) & Jaipur foot (mean=64.62±4.12) showed significant difference indicating Jaipur foot showed better step length than SACH foot. The stride length (Table-2 and figure-2) using SACH foot (mean=125.75±17.33) & Jaipur foot (mean=128.80± 18.17) showed significant difference (t-value =2.19, p-value=0.037) indicating Jaipur foot produces more stride length than SACH foot. The velocity (Table-4 and figure-4) using SACH foot (mean=0.93±.256) & Jaipur foot (mean=0.96±0.256) revealed no significant difference (t-value=1.65, p-value=0.109) indicated that both feet produces equal velocity in unilateral transtibial amputees.

ENERGY EXPENDITURE
The result of physiological cost index (Table-5 and figure-5) revealed that no significant difference found using SACH foot (Mean=0.104±0.064) & Jaipur foot (Mean=0.126±0.154, t-value=0.81, p-value=0.422).

DISCUSSION
It has already been studied that the energy expenditure in transtibial amputees using SACH foot increases significantly more than normal subject. For the subject with unilateral transtibial amputees, it is very important to determine that which prosthetic foot are more compatible in terms of energy efficiency & stride characteristics, because it has already been said that in unilateral transtibial amputation the normal functions can be expected for most of the amputees. The purpose of this study was to determine whether the stride characteristics & physiological cost index significantly difference between unilateral transtibial amputees using prosthesis with SACH foot & Jaipur foot. The mean of cadence using Jaipur foot (mean=81.9±15.81) & SACH foot (71.55±13.85) & the mean of velocity (m/s) using Jaipur foot (mean=.96±.256) & SACH foot (.96 ±.256), revealed no significant difference in cadence & walking speed. The results correlate with the earlier studies by the Power et.al in which he found that the cadence comparing five prosthetic feet was not significantly different. The findings of the different study (Doane et.al, Lehmann et.al.Nielsen et.al.)18,23,24, showed that there is no significant difference in velocity using various prosthetic feet. Thus it shows that the finding of the present study is not incidental.
The mean of Stride characteristics in terms of Stride length of Jaipur foot (Mean=128.80±18.17) was significantly higher than the SACH foot (mean=125.75± 17.33). The Step length of Jaipur foot (Mean=65.62±9.12) was also significantly higher than the SACH foot (mean=62.41±7.81) indicating that SACH foot result in slower stride length & step length than Jaipur foot. The previous study (Arya AP et. al., 1995) stated that the performance of the Jaipur foot is more natural & nearer to the normal foot as compared to the SACH foot & Seattle foot. The better stride length & step length produced by Jaipur foot in unilateral transtibial amputee may be due to its natural appearance & more natural rocker action than SACH foot as said in previous study (Arya AP et.al19., 1995, Kabra & Naranan8, 1990). The mean of PCI of SACH foot (Mean=0.104±0.064) & Jaipur foot
(Mean=0.126±0.154, t-value=.81) showed no significant difference. In terms of energy expenditure, the finding of the present study is in the agreement with the study by Huang et.al.17, compared the energy cost in various energy storing prosthetic feet.
These data suggested that both the feet are compatible to the unilateral transtibial amputee. This is found that the prosthesis with Jaipur foot was better in stride length & step length. The energy expenditure using both the feet is not significantly different. The ultimate effect is to show effect on gait efficiency & energy expenditure in unilateral transtibial amputees using two biomechanical feet which may help the clinician in selecting the foot during the prescription of unilateral transtibial amputees occurred due to traumatic amputation.

FUTURE RESEARCH
As earlier mentioned, this study uses a small sample of subjects. So the study can be done including larger sample of subjects. This study was concluded on unilateral transtibial amputees of traumatic type. The future research involving dysvascular type unilateral transtibial amputees will generate the broadened aspect.

CONCLUSION
This study concludes that although both the feet are compatible to the persons with transtibial amputees, but it is found that the Jaipur foot showed better stride characteristics in terms of stride length & step length. But there were no significant difference found in cadence & velocity comparing both the feet. Also there was no significant difference found in energy expenditure during walking either using SACH or Jaipur feet. Thus concluding that both the feet are equally compatible to the amputee gait & both the feet consumes equal energy during walking.

ACKOWLEDGEMENT
The author thanks his parents for continuous support and moral backup. He also thanks to his esteemed Guide Mr. Tarun Kumar Kulshreshtha, Managing Director Total O&P India (P) Ltd, Noida, UP for his support throughout the study. He specially thanks to Dr. Chitra Kataria, Principal, ISIC, Institute of Rehab. Sciences, New-Delhi, Mr Gautam Jain, Head clinical Services, Endolite India Pvt.Ltd, New-Delhi for their unwavering encouragement, valuable advice & expertise.
References
1. Boontje AH. (1980).Major Amputation of the lower extremity for vascular disease. Prosthetics & Orthotic International; 4:87-89.
2.Bard G, Ralston JH (1959).Measurement of energy expenditure during ambulation, with special reference to evaluation of assistive devices. Archives of physical medicine and Rehabilitation; 40:415-420.
3.Murray DG. (1965).Below knee amputation in the aged: Evaluation and prognosis. Geriatrics; 20:2033-2038
4.Smith DG, Micheael JW, Bowker. (2003) Atlas of amputations & limb deficiencies, surgical, prosthetic, & rehabilitation principles.
5.Molen NH (1973).Energy-Speed relation of below knee amputees walking on a motor driven trademill.Int Z Angew Physiol; 31:173-185.
6.Torburn L, Perry J, Ayyappa E, Shanfield SL (1990).Below knee amputee gait with dynamic elastic response feet: a pilot study. J Rehabil Res Dev; 27(4):369-384.
7.Torburn L,Powers CM,Guiterrez R,Perry J(1995).Energy expenditure during ambulation in dysvascular & traumatic below knee anputee:a comparison of five prosthetic feet.J Rehabil Res Dev;32(2):111-119.
8.Kabra SG &Narayanan R.(1991).Equipments &methods for laboratory testing of ankle foot prosthesis as exemplified by the Jaipur foot. J Rehabil Res Dev; 28(3):23-34.
9.Craig J.Prosthetic feet for low income group. Journal of prosthetic and orthotics online library.
10.Craig J.Biomechanical & Metabolic comparison of SACH &Seattle feet in below knee amputees. Journal of prosthetics and orthotics online library.
11.Pinzur MS et al. (1995).The effect of prosthetic alignment of relative limb loading in persons with transtibial amputation: A preliminary report. J Rehabil Res Dev; 32:373-377.
12. Rossi SA, Doyle W, Skinner HB (1995).Gait Initiation of persons with below knee amputation: The characterization and comparison of force profile. .J Rehabil Res Dev; 32:120-127.
13. Saunders JE, Daly CH, Burgess EM (1993).Clinical measurement of normal and shear stresses on a transtibial stump: Characteristic of wave form shape during walking. Prosthetics orthotics international.
14.Barth et al (1992).Gait analysis & energy cost of below knee amputees wearing six different prosthetic feet. J Prosth Orthot; 4:63-75.
15.Cassias JM, et al. (1995).Bioenergetics comparison of a new energy storing foot & SACH foot in traumatic below knee vascular amputations. Arch Phys Med Rehabil; 76(1):39-44.
16.Gitter et al. (1991).Biomechanical analysis of the influence of prosthetic feet on below knee amputee walking. Am J Phys Med Rehabil; 70(3):142-148.
17. Huang GF, Chou YL, Su FC. (2000).Gait analysis & Energy consumption of below knee amputees wearing three different prosthetic feet. Gait Posture; 12(2):162-168.
18. Nielsen DH,Shurr DG,Golden JC,Meier K(1988).comparison of energy cost & gait efficiency during ambulation in below knee amputees using different prosthetic feet.J Prosthet Orthot;1:24-31.
19.Arya AP.et al. (1995).A biomechanical comparison of SACH, Seattle & Jaipur foot using ground reaction forces. Prosthetics Orthotics international; 19(1):37-45.
20.Astrand PO, Rodahl R. (1970).Text book of work physionlogy.New-york.McGrawHill:9-43
21.Hornby TG,Zemon DH,Campbell D.(2005).Robotic assisted, body weight supported treadmill training in individuals following motor incomplete spinal cord injury. Physical Therapy; 85(1):52-63.
22.Rose J, et.al. (1989).Energy cost of walking in normal children & in those with cerebral palsy: comparison of heart rate & oxygen uptake. Journal of Pediatric Orthopedic; 9:276-279.
23. Lehmann JF et.al. (1993).Comprehensive analysis of energy storing prosthetic feet: flex foot &Seattle foot vs. Standard SACH foot. Arch Phys med Rehabil; 74:1225-1231.