Muscle activation patterns during functional movements in transtibial amputees

Arnold, Sarah (2018-11)

Thesis (MA)--Stellenbosch University, 2018.

Thesis

ENGLISH ABSTRACT: Functional movement capabilities of individuals with unilateral transtibial amputations are altered due to muscle loss and prosthesis limitations compared to healthy, typical individuals. The extent of the adaptions made during functional activities is however, unknown. The purpose of the study was to gain a better understanding of unilateral transtibial amputees (UTTA) muscle activation levels during functional activities. A systematic review (article one) relating to the gait and balance of UTTA was completed. It revealed the need for research relating to muscle activation and movement strategies during functional activities. Stage two of the Van Mechelen model was addressed through biomechanical analysis during single leg balance (SLB) and sit-to-stand-to-sit (SiStSi) tasks through muscle activation and biomechanical analysis. The study included 12 UTTA (34±10 years) and 13 able-bodied controls (CON) (34±11 years). The average time since amputation was 10±7 years. Each UTTA made use of their personal prosthesis for the observational testing. The participants were required to perform a unilateral SLB task followed by 10 continuous SiStSi movements. Muscle activation was measured for seven muscle groups using surface electromyography (EMG) together with a three dimensional biomechanical analysis. The results of article two relates to the single leg balance activity. Significantly greater muscle activation levels were found for the lumbar erector spinae (LES), gluteus medius (Gmed), gluteus maximus (Gmax), biceps femoris (BF) and vastus lateralis (VL) (p<0.05) for the affected side (AF) in comparison with the unaffected side (UN) and CON. Greater hip flexion moment and concentric hip power were observed for AF (p<0.05) while hip and knee flexion was greater than UN and CON (p<0.05). No significant differences were found for the knee and ankle joint moments during SLB (p>0.05). The SiStSi results are discussed in article three. Lower muscle activation levels were found for VL of AF compared to UN and CON, with greater activation levels of the tibialis anterior (TA) for UN than CON (p<0.05). The peak hip moment for AF during the SiSt was greater than UN and CON (p<0.05). Significantly greater hip power and hip flexion were identified for UTTA compared to CON (p<0.05), while the knee and ankle joint moments and powers were greater for UN than AF and CON (p<0.05). Lastly, vertical ground reaction force (vGRF) was significantly higher for UN than AF (p<0.05) The main findings included greater muscle activation of the muscles surrounding the hip joint of UTTA during the SLB and the SiStSi activities. Joint overloading was noted for the UN knee as well as overcompensation by the UN ankle during the SiStSi. Lastly, asymmetry was observed in the vGRF between the AF and UN sides during the SiStSi.

AFRIKAANSE OPSOMMING: Aangepaste funksionele bewegingsvermoeë kom voor by individue met unilaterale transtibiale amputasies (UTTA) wanneer hulle met gesonde tipiese persone vergelyk word. Verlies van spierfuksie en die beperkings van die prostese speel ‘n rol in kompenserende bewegings, alhoewel die mate van aanpassings tydens funksionele aktiwiteite onbekend is. Die doel van hierdie studie was om meer kennis te verkry rakende die spieraktiveringsvlakke van UTTA gedurende funksionele aktiwiteite. ‘n Sistematiese oorsig (artikel een) aangaande die looppatrone en balans van UTTA het die behoefte aan verdere navorsing met betrekking tot spieraktiveringsvlakke en bewegingstrategieë gedurende funksionele aktiwiteite in UTTA uitgelig. Fase twee van die Van Mechelen model was aangespreek deur biomeganiese analises en meting van spieraktiveringsvlakke tydens die een-been-staan en die sit-tot-staan-tot-sit (SiStSi) aktiwiteite. Hierdie studie het 12 UTTA (34±10 jaar) en 13 tipiese persone (kontrole groep) (34±11 jaar) ingesluit. Die gemiddelde tyd sedert amputasie was 10±7 jaar. Tydens hierdie waarnemingstudie het elke UTTA het van sy eie persoonlike prostese gebruik gemaak. Daar was van elke deelnemer verwag om ‘n een-been-staan (SLB) beweging uit te voer, wat opgevolg was met 10 aaneenlopende SiStSi bewegings. Driedimensionele biomeganiese analise sowel as oppervlak elektromiografie van sewe spiergroepe was gemeet tydens hierdie bewegings. Die resultate van die SLB aktiwiteit word in artikel twee bespreek. Dit dui op beduidend groter spieraktiveringsvlakke aan van die lumbale erector spinae (LES), gluteus medius (Gmed), gluteus maximus (Gmax), biseps femoris (BF) en die vastus lateralis (VL) (p˂0.05) van die geaffekteerde kant van UTTA, in vergelyking met beide die ongeaffekteerde kant en die kontrole groep. Groter heupfleksor draaimoment en konsentriese heupdrywing was gevind vir die geaffekteerde kant (p˂0.05), te same met groter heup- en kniefleksie (p˂0.05) wanneer dit met die ongeaffekteerde kant en kontrole groep vergelyk word. Geen betekenis verskille was tydens die SLB gevind vir nóg die knie- nóg die enkelgewrig draaimoment nie. Die bevindinge van die SiStSi word in artikel drie bespreek. Dit toon laer spieraktiveringsvlakke aan vir VL van die geaffekteerde kant in vergelyking met die ongeaffekteerde kant en die kontrole groep. Hoër spieraktivering was gevind vir die tibialis anterior (TA) van die ongeaffekteerde been van UTTA in vergelyking met die kontrole groep (p˂0.05). Die piek heupdraaimoment vir die geaffekteerde kant van UTTA was beduidend hoër as vir die ongeaffekteerde kant en die kontrole groep tydens die SiSt (p˂0.05). Heupdrywing en heupfleksie was beduidend meer vir UTTA as vir die kontrole groep (p˂0.05), terwyl die knie- en enkelgewrig draaimoment van die ongeaffekteerde been groter was as die geaffekteerde been van die kontrole groep (p˂0.05). Vertikale grondreaksiekrag was beduidend hoër vir die ongeaffekteerde been as vir die geaffekteerde been van die UTTA (p<0.05). Die hoofbevindinge sluit in hoër spieraktiveringsvlakke van die spiere rondom die heupgewrig aan die geaffekteerde kant van UTTA gedurende beide die SLB en SiStSi aktiwiteite. Verder is gevind dat die kniegewrig van die ongeaffekteerde kant oorlaai word, sowel as dat die enkle-gewrig aan die ongeaffekteerde kant tot ‘n betekenisvolle mate kompenseer vir die verliese aan die geaffekteerde kant tydens die SiStSi. Asimmetriese vertikale grondreaksiekrag tussen die geaffekteerde en ongeaffekteerde kant kom voor tydens die SiStSi.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/105173
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