1. BALANCE AND POSTURAL ADJUSTMENTS
Implications for Amputee Rehabilitation
NSWPAR, March 2007

2. SEARCH STRATEGY Searched Medline, Cinahl, Embase Keywords
amputee (816)
rehabilitation (96126)
posture
balance
Limit to human, english = 17

3. DIFFERENCES BETWEEN AMPUTEES AND NORMALS
Loss of sensory feedback
Loss of proprioception
Altered postural sway
(Buckley et al, 2002; Miller and Deathe, 2004)
Loss of sensation – at best they re-map receptors within the stump
Increased postural sway – Buckley et al, 2002 (UK – footie players) – CoP excursions were significantly greater for amputees(high level AK and BK studied, flex feet and hydraulic knees, iceros liners…..) in both the m-l and a-p directions in quiet standing. Dynamic standing balance on a ‘Stabilimeter’ (like a single axis wobble board m-l and a-p) was also worse for the amputee group cf. normals. In normals – ankle strategies are used for quiet standing ie. df,pf,inv,evers…….in large pertubations, hip strategies or stepping are utilized.

4. DIFFERENCES BETWEEN AMPUTEES AND NORMALS
Biomechanical differences
GAIT
Heel contact – hip muscle activity in abductors, eccentric knee extensors (shock absorption)
Midstance – dynamic stability maintained by hip abductors
Push off – hip flexor activity for propulsion
Swing – normal muscle activity
(Sadeghi et al, 2001)
BALANCE
↓ WB’ing on prosthetic side
Greater problems maintaining dynamic balance esp. in the a-p direction
Lack of ‘ankle strategies’ are partially compensated by ‘hip strategies’
More dependant on vision
More prone to interference from concurrent attention demanding tasks
(Buckley et al, 2002)
Sadegi et al – Gait study of 5 male TT amps average age of 27 +/ Used cameras and force plates.

5. DIFFERENCES BETWEEN AMPUTEES AND NORMALS
STEPS
↑ time taken to load prosthesis in stance
↑ peak m-l and a-p CoP and CoM displacements and velocities at heel off and at foot contact
Differences were NOT between AK/BK amputees
(Jones et al, 2004)
WEIGHT SHIFTING
‘hip strategies’ rather than ‘ankle strategies’ in anticipatory postural adjustments
(Mouchnino et al, 1998)
Jones et al – compared stepping up and down with amputees (BK and AK)/normals – normals have a characteristic stereotypical displacement of the CoM and CoP that result from a consistent pattern of lower limb muscle activity. This includes the same ‘anticipatory postural adjustments, predominantly around the ankles PF/DF/inv/ever. In unilateral amputees, they need to adopt new alternative strategies unilaterally specific to each motor task eg which foot leading, going up or down.
↑ stance time is a strategy aimed at counteracting the stability and propulsion limitation of the prosthetic limb
Mouchnino et al, 1998) – leg thrusting to 45 deg laterally (Marsielle, France) – shift in CoP to stance leg in anticipation of movment – when stance leg is amputated, rather than gastrocs, they got a burst of TFL instead.

6. STATISTICS 52% of unilateral AKA/BKA’s had a least one fall per year
(Miller and Deathe, 2004)
Inpatient rehabilitation
1 in 5 LL amputees fall
18% sustaining an injury
Risk factors include age, LOS, comorbidities, cognitive impairment, >2 medications (benzo’s and opiates), bilateral amputation
(Pauley et al, 2006)
Multiple falls predicted by:
TUG > 19 seconds
180 degree turn > 3.7 seconds, > 6 steps
Four Stick Step Test > 24 seconds
Locomotion Capabilities Index < 15
(Dite et al 2007)
Falls – incidence of falls in normal community living elderly approx 30% per year. Ass. With loss of mobility and self imposed restrictions on activity which further lead to lack of mobility – downward spiral……
Miller and Deathe, Balance confidence – 65% of amputees report levels of balance confidence considered low enough that they would benefit from further interventions (education, activities and gait training). 76% reported self imposed restrictions because of this.
Pauley et al – retrospective cohort of 1267 patients in canada.
Dite et al, 2007
Timed up and go – usual protocol.
180 degree turn from TUG filmed and time and steps calculated.
4 sticks placed in cross, patient must step into all four squares (forward, sideways R + L, backwards) – time recorded.
LCI – 14 item interview designed for amputees. Self reported ability to perform activities whilst wearing prosthesis.

7. STATISTICS Balance confidence related to; Mobility devices used Age
Fear of falling
Good perception of health
Automatic walking
Depression
NOT Amputation cause or level of amputation??
(Miller and Deathe, 2004)

8. MEASUREMENT OF BALANCE
Activities-specific Balance Score (ABC scale)
(Powell and Myers, 1995)
L-Test of Functional mobility
(Deathe and Miller, 2005)
Step Test
Berg Balance Scale
Functional Reach
Frenchay Activities Index (FAI)
Prosthetic evaluation questionaire – mobility scale (PEQ-MS)
4 stick step test
ABC – (Canada)–16 point scale
Reliable in LL amputee population
Scores <80 considered to need intervention
Is more useful compared with the Falls Efficacy score (1990) – no ceiling effect, better to distinguish higher level function….the last question (and most difficult task is walking on icy sidewalk, so perhaps not good for Australia??
Powell and Myers, 1995) - ABC scores – (sample of 245 AK and BK’s, community living, wearing leg daily, mean age 60years, av 17 years post amputation, 56% traumatic etiology) 25% of amputees scoring <50 on ABC
L-Test of Functional mobility – stand up, walk 3 m, then turn 90 deg down a corridor, walk 7 m, turn around and sit back down. 2 transfers, 2 90 deg turns to alternate directions, and one 360 deg turn. TUG has ceiling effects and doesn’t provide sufficient challenge for all amputees. Authors tested for reliability and validity amongst 93 unilateral (BK and AK) amputees
Step test – no of steps on/off a 7.5cm block in 15 seconds, no hands. Quick and easy, not tested for reliability in amputees???
Berg Balance Scale – too long……..again, not tested in amputees??
Functional reach – quick and easy, tests mainly a-p stabililty which is the most effected in amputees, again not tested in amputees???
Frenchay Activities Index (FAI) – 15 items, measures the participation in activities ranging from preparing meals to working over the past 3 to 6 months. Reliability in amputees ICC = 0.78, also valid……..too long, not clinically very useful???
Prosthetic evaluation questionaire – mobility scale (PEQ-MS) – 13 item questionnaire, self reported. Evaluates the perceived potential for mobility using prosthetic devices over the past 4 weeks.

9. EFFICACY OF TRAINING Matjacic and Burger, 2003
Pilot study of balance training ‘BalanceReTrainer’ NOT RCT.
3 outcome measures pre-post training;
Single leg balance on prosthesis
3 (2.8) sec → 4.3 (4.5) sec, not significant.
TUG
6.2 (1.9) sec → 5.4 (1.5) sec, not significant
10m walk time
5.5 (1.5) sec → 4.5 (0.9) sec, p<0.05 significant
Matjacic and Burger, 2003
Slovenia………..14 BKA’s, av age 49 years, av 9 years post amputation secondary to mine accidents. Subjects were admitted to the inpatient clinic for 5 days for fitting of a new prosthesis. The ONLY training given was 20 minutes per day using the BalanceReTrainer (used prev in stroke/TBI populations with some success???). BalanceReTrainer involved the patient shifting their pelvis in order to track a mouse to a target that was pictured on a PC in front of them. Practice was progressed by increasing the distance tracked, reducing the time to get to the target and holding the position for longer periods of time. Potential support was available at the pelvis, but rarely needed, so no upper limb support was allowed (it was impossible to fall). A physiotherapist supervised the therapy and stopped any compensations/excessive trunk movement eg trendelenburg/forward flexion of the trunk.
3 outcome measures pre-post training; differences via t tests.
Problems with interpreting results;
Were the changes in performance the result of the training or due to a change in the prosthesis (better fit?? Underestimated results because they still have to learn to use the new prosthesis??
Authors suggest that training effects would be even greater with acute amputees (as alternative sensory motor strategies are learnt at this stage…)
My comments – not task specific at all, artificial environment, assessors not blinded so may have been biased?

10. EFFICACY OF TRAINING Geurts et al, 1992, (Netherlands)
Not an RCT, pre-post rehab measures cf. age matched controls
Force platform measures (GRF and CoP)
Eyes open
Partial vision
Eyes closed
Conclusion
“…a central reorganization of postural control takes place, in which sensory determinants of motor recovery may play a critical role…”
Isakov et al, 1992 (Israel)
V. similar study, no difference in postural sway eyes open or closed post 3-4 weeks rehab
Subjects - recent LL amputees, n=10, 2 dropouts
- age ranges 25 – 84yr, vascular and traumatic
- BK, AK and thru knees
- Initial rehab ‘aircast’ – study protocol commenced on provision of definitive prosthesis
- 8 months rehab consisting of progressive wb’’ing and mobility tasks, multy skilling
Results - Small improvements in postural sway (ap and ml) (??balance) with eyes open in amputee group (p<0.6)
- large improvments in postural sway with eyes closed (p<0.5)
- “…visual dependence approaching normal values at the end of rehabilitation…”
Same study, same year….Isakov et al (1992) – 11 BKA’s, this time only 3-4 weeks of rehabiliation. Significant differences in sway with both eyes open and closed, but no improvments in either condition post rehab…..?????3-4 weeks isn’t long enough, but 8 months is?? (geurts et al)

11. EFFICACY OF TRAINING Geurts et al, 1991(Netherlands)
Not an RCT, pre-post rehab measures cf. age matched controls
Force platform measures (GRF and CoP)
Concurrent cognitive task
Standing, no cognitive task
Conclusion;
“…restoration of automaticity of postural control”
Subjects - recent LL amputees, n=10, 2 dropouts
- age ranges 25 – 84yr, vascular and traumatic
- BK, AK and thru knees
- Initial rehab ‘aircast’ – study protocol commenced on provision of definitive prosthesis
- 8 months rehab consisting of progressive wb’’ing and mobility tasks, multy skilling (catching balls etc – not cognitive tasks??)
- Concurrent cognitive task was ‘Modified Stroop test’ – a word (yellow, blue, red, green) appeared on a screen in different and incongruent colours. Subjects had to say the colour of the print as fast as possible, and resist the temptation just to read the words.
Results; - ‘Amputee group showed interference with postural sway (??balance ability) with concurrent task both at the start (p<0,05) and the end of rehab (p<0.05) …..control group were only measured once, and didn’t show interference (non significant)….??insufficent numbers…
- comparing pre/post rehab, the amputee group significantly improved on concurrent task with postual sway…..(not specifically trained)

12. IMPLICATIONS FOR AMPUTEE REHABILITATION
Anticipatory postural adjustment strategies are unique for amputees and are task specific
Balance confidence is the biggest predictor for mobility outcomes in amputees – we need to train relevant ADL balance tasks for amputees to re-gain confidence
Therefore we need to cater rehab goals according to patient’s needs/adl interests – they can’t use strategies that worked for them premorbidly as they are quite different now eg. Stairs, walking, sit to stand, reaching, turning, standing……..everything
Don’t leave patients in the gym – supportive of functional retraining specific to their needs, leave the parallel bars and get outdoors – need for supervised and ongoing community mobility programmes
Increase patient confidence as best you can – repetition, reward successes, goal setting and achievement together with the patient and family
Miller et al 2001 – Canada, questionaire Also investigated automatism, medication count, pain, amputation level and balance confidence was the most significant….?not age.

13. REFERENCES
Buckley JG, O’Driscoll D, Bennett S (2002): ‘ Postural Sway and Active Balance performance in Highly Active Lower-Limb Amputees’ American Journal Physical medicine and Rehabilitation 81(1):13-20.
Dite W, Connor HJ and Curtis HC (2007) Clinical Identification of Multiple Fall Risk After Unilateral Transtibial Amputation. Archives of Physical Medicine Rehabilitation 88:
Evans WE, Hayes JP and Vermilion BD (1987): Rehabilitation of the bilateral amputee’ Journal of Vascular Surgery 5(4):
Geurts ACH, Milder TW, Neinhuis B and Rijken RAJ (1991): Dual-Task assessment of reorganization of posutal control in persons with lower limb amputation’ Archives Physical medicen and rehaibilaton 72,
Geurts ACH, Milder TW, Nienhuis B and Rijken AJ (1992): ‘Postural reorganization following lower limb Amputation’ Scandinavian Journal of Rehabilitation Medicine 24:83-90.
Hoffman MD, Sheldahl LM, Buley KJ, Sandford PR (1997). Physiological Comparison of Walking among bilateral Above-Knee amputee and Able-bodied subjects and a model to account for the differences in metabolic cost’ Archives Physical medicine and rehabilitation 78,
Isakov E, Mizrahi J, Ring H, susak Z and Hakim N (1992): ‘Standing Sway and weight bearing distribution in people with below knee amputations” Archives Physical Medicine and rehabilitation 73:
Jones SF, Twigg PC, Scally AJ, Buckley JG (2005): ‘The gait initiation process in unilateral lower-limb amputees when stepping up and stepping down to a new level’ Clinical Biomechanics 20(4):
Majacic Z and Burger H (2003): ‘Dynamic balance training during standing in people with trans-tibial amputation: a pilot study’ Prosthetics and Orthotics International 27,
Millar WC and Deathe AB (2004): ‘A prospective study examining balance confidence among individuals with lower limb amputation’. Disability and Rehabilitation 26:14/15;

14. Millar WC, Deathe AB, Speechley M
Millar WC, Deathe AB, Speechley M., Koval J (2001): The influence of falling, fear of falling, and balance confidence on prosthetic mobility and social activity among individuals with a lower extremity amputation’ Archives of Physical medicine and rehabilitation 82:
Mouchnino L, Mille ML, Cincera M, Bardot A, Delarque A, Pedotti A Massion J (1998): ‘ Postural reorganization of weight-shifting in below-knee amputees during leg raising’ Experimental Brain Research 121(2):205-14
Nadollek H, Brauer S and Isles R (2002) Outcomes after trans-tibial amputation: the relationship between quiet stance ability, strength of hip abductor muscles and gait. Physiotherapy Research International 7(4)
Pauley T, Devlin M, Heslin K (2006): ‘Falls Sustained during inpatient Rehabilitation After Lower limb amputation: Prevalence and Predictors’ American Journal Physical medicine and rehabilitation, 85(6):
Powell L ad Myers A (1995): ‘The Activities-specific Balance confidence (ABC) scale’ Journal of Gerontology, 50: M28-M34.
Sadegi H, Allard P and Dunhaime M (2001): Muscle Power Compensatory Mechanisms in Below-Knee Amputee Gait. American Journal of Physical Medicine 80 (1):
Viton JM, Mouchnino L, Mille ML, Cincera M, Delarque A, Pedotti A, Bardot A and Massion J (2000): Equilibrium and movement control strategies in trans-tibial amputees’ Prosthetics and Orthotics International, 24:

15. Questions for panel Upper limb support – acute and training phases
Core stability training
Balance training v’s mobility training
Measurement of balance in the clinical setting