University of Groningen Effects of lower extremity power training on gait biomechanics in old adults Beijersbergen, Chantal

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University of Groningen

Effects of lower extremity power training on gait biomechanics in old adults Beijersbergen, Chantal

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Beijersbergen, C. (2017). Effects of lower extremity power training on gait biomechanics in old adults: The Potsdam Gait Study (POGS). Rijksuniversiteit Groningen.

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Appendices

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Appendix A

APPENDIX A

Supplementary data chapter 2

Ta

ble A.1.

Mec

hanical plasticity of old adults’

gait. Bod y mass nor malized hip , knee , and ankle po w er dur

ing stance phase of gait

Joint po w er s dur ing gait, W/kg Po w er , % of total Reference Group Age n Ankle Knee Hip Total Ankle Knee Hip Comments 1Cofré et al 2011 Young 27.0 12 2.90 0.27 0.39 3.6 81.5 7.6 10.9 1.0 m/s Old 67.0 8 2.59 0.23 0.51 3.3 77.9 6.8 15.4 Young 27.0 12 3.96 0.67 0.65 5.3 75.0 12.7 12.4 1.3 m/s Old 67.0 8 3.50 0.59 0.79 4.9 71.7 12.1 16.2 Young 27.0 12 5.29 1.28 1.10 7.7 69.0 16.7 14.3 1.6 m/s Old 67.0 8 4.12 1.08 1.32 6.5 63.2 16.5 20.3 Young 27.0 12 4.38 0.83 0.86 6.1 72.2 13.6 14.2 SS = 1.4 m/s Old 67.0 8 3.79 0.69 1.02 5.5 68.9 12.6 18.5 2DeV

ita & Hor

tobágyi 2000 Young 21.6 14 5.16 2.15 1.00 8.3 62.1 25.9 12.1 Fr om fig . 3 / mean mass Old 69.0 12 3.73 1.10 1.10 5.9 62.8 18.6 18.6 3Judge et al 1996 Young 26.0 32 3.50 0.16 0.55 4.2 83.1 3.8 13.1 Old 79.0 26 2.90 0.17 0.47 3.5 81.9 4.8 13.3 4K er rigan et al 1998 Young 28.5 31 2.13 0.53 0.59 3.3 65.5 16.3 18.2 Pr efer

red speeds differ

ent betw een g roups Old 72.7 31 1.70 0.36 0.49 2.6 66.7 14.1 19.2 5McGib bon & Kr ebs 2004 Young 29.7 45 3.90 0.52 0.53 4.9 78.9 10.4 10.7 Old 71.1 37 3.14 0.72 0.61 4.5 70.3 16.0 13.7 6Monaco et al 2009 Young 26.4 9 1.80 0.20 0.53 2.5 71.1 7.9 20.9 Fr om fig . 3, fr5= 1.19 m/s Old 70.4 8 1.10 0.45 1.00 2.6 43.1 17.6 39.2 Fr om fig . 3, fr5=1.14 m/s 7Sa velberg et al 2007 Young 22.8 20 4.40 1.47 0.42 6.3 69.9 23.3 6.7 Slo w speed Old 67.8 20 3.18 0.88 0.92 5.0 63.9 17.7 18.5 8Silder et al 2008 Young 26.0 20 2.56 0.37 Slo w Old 73.0 20 2.34 0.68 Young 26.0 20 3.49 0.54 Pr efer red Old 73.0 20 3.09 1.01 Young 26.0 20 4.48 0.66 Fast Old 73.0 20 3.61 1.34 Mean Young Mean 26.2 19.9 3.66 0.81 0.67 5.2 72.8 13.8 13.3 SD 2.1 10.4 0.96 0.33 0.30 1.4 10.5 4.7 7.4 Old Mean 70.5 17.4 2.98 0.63 0.87 4.4 67.0 13.7 19.3 SD 3.6 9.8 1.07 0.61 0.21 1.8 6.1 6.6 3.9

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Appendix A

REFERENCES

1. Cofré LE, Lythgo N, Morgan D, Galea MP. Aging modifies joint power and work when gait speeds are matched. Gait Posture. 2011;33:484–9.

2. DeVita P, Hortobágyi T. Age causes a redistribution of joint torques and powers during gait. J. Appl. Physiol. Bethesda Md 1985. 2000;88:1804–11.

3. Judge JO, 3rd RBD, Ounpuu S. Step length reductions in advanced age: the role of ankle and hip kinetics. J. Gerontol. Biol. Sci. Med. Sci. 1996;51:M303-12.

4. Kerrigan DC, Todd MK, Croce UD, Lipsitz LA, Collins JJ. Biomechanical gait alterations independent of speed in the healthy elderly: evidence for specific limiting impairments. Arch. Phys. Med. Rehabil. 1998;79:317–22.

5. McGibbon CA, Krebs DE. Discriminating age and disability effects in locomotion: neuromuscular adaptations in musculoskeletal pathology. J. Appl. Physiol. Bethesda Md 1985. 2004;96:149–60.

6. Monaco V, Rinaldi LA, Macri G, Micera S. During walking elders increase efforts at proximal joints and keep low kinetics at the ankle. Clin. Biomech. Bristol Avon. 2009;24:493–8.

7. Savelberg HH, Verdijk LB, Willems PJ, Meijer K. The robustness of age-related gait adaptations: can running counterbalance the consequences of ageing? Gait Posture. 2007;25:259–66.

8. Silder A, Heiderscheit B, Thelen DG. Active and passive contributions to joint kinetics during walking in older adults. J. Biomech. 2008;41:1520–7.

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Appendix A

Ta

ble A.2.

Effects of str

ength training on gait speed and maximal quadr

iceps str ength Gait speed, m/ Tor que (Nm), Force (N), chair rise n umber Reference Age n Inter vention Weeks Distance, m Time, min Initial Final Change, % Intial Final Change, % Comments 1 Buc hner et al. 1997 75.0 25

3/wk endurance training for 26 wks

26 40.0 1.3 1.3 -1 88 97 10 74.0 25 3/wk str

ength trainng for 26 wks

40.0 1.4 1.4 4 86 94 9 75.0 25 3/wk endurance+str ength trg for 26 wks 40.0 1.4 1.4 5 80 87 9 2 Cao et al. 2007 65.0 20 2/wk mix ed training for 12 wks 12 10.0 1.9 2.0 4 15 17 14 3 Capodaglio et al. 2007 76.6 19 1/wk. str

ength training for 52 wks

52 6.0 0.9 1.1 24 124 137 10 GU&G 77.5 19 1/wk. str

6.0 0.8 1.0 25 79 90 13 76.6 19 1/wk. str

6.0 1.3 1.4 5 124 137 10 6MWT 77.5 19 1/wk. str

6.0 1.3 1.3 4 79 90 13 4 Ca vani et al. 2002 69 22 3/wk. str

6 6.0 1.5 1.6 9 13 17 31 5 Fahlman et al. 2011 75.0 46 3/wk. str

ength traning for 16 wks

16 3.7 1.4 1.5 6 54 54 -1 Str ength = number of c hair rises in 30 6 Henw ood et al. 2008 69.6 19 2/wk str

24 6.0 1.5 1.6 7 317 372 17 7 Holviala et al. 2006 56 48 2/wk. str

+ 21 wks 21 10.0 8 100 130 27 1RM in kg . estima ted fr om fig 2 59 41 2/wk. str

+ 21 wks 10.0 18 150 175 18 1RM in kg . estima ted fr om fig 2 8 Jette et al. 1999 75.4 107 2/wk

Thera-Bands training for 24

wks 24 6.0 0.4 0.5 8 135 146 8 9 Judge et al. 1993 81.6 18 3/wk. str

12 1.0 1.1 8 60 71 18 10 Judge et al. 1994 80.3 28 3/wk. str

13 8.0 1.1 1.2 7 73 86 18 11 Kalapotharak os et al. 2005 64.6 11 3/wk. high str

ength training for

12 wks 12 6.1 1.7 2.1 30 423 753 78 65.8 12 3/wk. modera te str ength training for 12 wks 12 6.1 1.6 2.1 33 394 568 44 12 Kr ebs et al. 1998 74.8 54 3/wk

Thera-Bands training for 6

mths 24 10.0 1.0 1.1 5 138 161 17 R = 0.29. P= 0.02 fr ee gait speed and m uscle str ength 13 Liu-Ambr ose et al. 2010 69.6 51 1-2/wk balance or str ength training for 52 wks 52 4.0 1.2 1.4 17 326 377 16 Mean of 3 g roups 14 Lord et al. 1996 71.1 66 2/wk. endurance+str etc h for 10 wks 10 11.2 1.1 1.2 5 23 27 v

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12 4.0 12 54 16 Pr otas & Tissier 2009 78.0 9 3/wk. functional and str ength training for 3 mths 12 0.7 1.1 51 231 308 33

RM = sum for both legs; usual gait speed this r

ow

fast gait speed this r

ow 17 Sc hlic ht et al. 2001 72.0 11 3/wk. str

8 13.7 2.0 2.4 17 10 8 15 STS test 18 Sk elton et al. 1995 79.5 47 3/wk. str

12 118.0 1.4 1.2 -7 200 240 27 19 Symons et al. 2005 72.4 30 3/wk. str

12 80.0 1.4 1.3 -7 98 112 14 Da ta combined for 3 differ ent training g roups 20 W esthoff et al. 2000 75.9 10 3/wk. str

10 20.0 0.7 0.9 18 58 89 53 Mean 72.1 30.2 18.2 21.7 5.5 1.25 1.38 11.7 133.8 170.8 22.1 SD 6.6 21.8 12.6 28.9 1.0 0.37 0.42 12.7 114.8 176.1 17.4 Min 56.0 6.0 3.7 4.0 0.45 0.49 -7.0 9.9 8.4 -0.7 Max 81.6 52.0 118.0 6.0 2.01 2.35 51.4 422.7 752.9 78.1 Sum 815 REFERENCES

1. Buchner DM, Larson EB, Wagner EH, Koepsell TD, Lateur BJ de. Evidence for a non-linear relationship between leg strength and gait speed. Age Ageing. 1996;25:386–91.

2. Cao ZB, Maeda A, Shima N, Kurata H, Nishizono H. The effect of a 12-week combined exercise intervention program on physical performance and gait kinematics in community-dwelling elderly women. J. Physiol. Anthropol. 2007;26:325–32.

3. Capodaglio P, Edda MC, Facioli M, Saibene F. Long-term strength training for community-dwelling people over 75: impact on muscle function, functional ability and life style. Eur. J. Appl. Physiol. 2007;100:535–42.

4. Cavagna GA. Storage and utilization of elastic energy in skeletal muscle. Exerc. Sport Sci. Rev. 1977;5:89–129.

5. Fahlman MM, McNevin N, Boardley D, Morgan A, Topp R. Effects of resistance training on functional ability in elderly individuals. Am. J. Health Promot. AJHP. 2011;25:237–43.

6. Henwood TR, Riek S, Taaffe DR. Strength versus muscle power-specific resistance training in community-dwelling older adults. J. Gerontol. Biol. Sci. Med. Sci. 2008;63:83–91.

7. Holviala JHS, Sallinen JM, Kraemer WJ, Alen MJ, Häkkinen KKT. Effects of strength training on muscle strength characteristics, functional capabilities, and balance in middle-aged and older women. J. Strength Cond. Res. 2006;20:336–44.

8. Jette AM, Lachman M, Giorgetti MM, Assmann SF, Harris BA, Levenson C, et al. Exercise--it’s never too late: the strong-for-life program. Am. J. Public Health. 1999;89:66–72.

9. Judge JO, Underwood M, Gennosa T. Exercise to improve gait velocity in older persons. Arch. Phys. Med. Rehabil. 1993;74:400–6. 10. Judge JO, Whipple RH, Wolfson LI. Effects of resistive and balance exercises on isokinetic strength in older persons. J. Am. Geriatr. Soc. 1994;42:937–46.

11. Kalapotharakos V, Smilios I, Parlavatzas A, Tokmakidis SP. The effect of moderate resistance strength training and detraining on muscle strength and power in older men. J. Geriatr. Phys. Ther. 2001. 2007;30:109–13.

12. Krebs DE, Jette AM, Assmann SF. Moderate exercise improves gait stability in disabled elders. Arch. Phys. Med. Rehabil. 1998;79:1489– 95.

13. Liu-Ambrose T, Nagamatsu LS, Graf P, Beattie BL, Ashe MC, Handy TC. Resistance training and executive functions: a 12-month randomized controlled trial. Arch. Intern. Med. 2010;170:170–8 14. Lord SR, Lloyd DG, Nirui M, Raymond J, Williams P, Stewart RA. The effect of exercise on gait patterns in older women: a randomized controlled trial. J. Gerontol. Biol. Sci. Med. Sci. 1996;51:M64-70. 15. Persch LN, Ugrinowitsch C, Pereira G, Rodacki AL. Strength training improves fall-related gait kinematics in the elderly: a randomized controlled trial. Clin. Biomech. Bristol Avon. 2009;24:819–25.

16. Protas EJ, Tissier S. Strength and speed training for elders with mobility disability. J. Aging Phys. Act. 2009;17:257–71.

17. Schlicht J, Camaione DN, Owen SV. Effect of intense strength training on standing balance, walking speed, and sit-to-stand performance in older adults. J. Gerontol. A. Biol. Sci. Med. Sci. 2001;56:M281-286.

18. Skelton DA, Young A, Greig CA, Malbut KE. Effects of resistance training on strength, power, and selected functional abilities of women aged 75 and older. J. Am. Geriatr. Soc. 1995;43:1081–7.

19. Symons TB, Vandervoort AA, Rice CL, Overend TJ, Marsh GD. Effects of maximal isometric and isokinetic resistance training on strength and functional mobility in older adults. J. Gerontol. Biol. Sci. Med. Sci. 2005;60:777–81.

--20. Westhoff MH, Stemmerik L, Boshuizen HC. Effects of a

low-intensity strength-training program on knee-extensor strength and functional ability of frail older people. J Aging Phys Act. 2000;8:325– 42.

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Appendix B

APPENDIX B

Figure B.2. Associations between changes in fast gait velocity and changes in muscle strength or power as a result of the power training (n = 15). Panel A: 3-RM gains averaged across four training exercises and fast

gait velocity: y = 0.83x + 61.6, R = 0.107, R2_{= 0.01, P = 0.703. Panel B: Changes in peak knee extensor}

power averaged over three contraction speeds and changes in fast gait velocity: y = 0.48x + 19.1, R =

0.086, R2_{= 0.00, P = 0.760. Panel C: Changes in peak knee flexor power averaged over three contraction}

speeds and changes in fast gait velocity: y = 0.36x + 23.1, R = 0.419, R² = 0.176, P = 0.121. Panel D: Changes in peak plantarflexor power averaged over three contraction speeds and changes in fast gait

velocity: y = 0.34x + 41.4, R = 0.259, R2_{= 0.07, P = 0.351.} 0 10 20 30 40 50 60 70 80 90 100 Leg

press extensionKnee flexionKnee Anklepress

3R M loa d (k g) * * * * 50 100 150 -20 -10 0 10 20 30 ∆ Average 3RM (%) -50 50 100 150 -20 -10 10 20 - 20 20 40 60 80 -20 -10 10 20 30 -20 -10 10 20 30 40 50 -20 _-10 10 20

∆ Fast gait velocity (%) A C D B 30 30 ∆ Average

KF power (%) ∆ Average PF power (%)

∆ Average

KE power (%)

∆ Fast gait velocity (%)

Figure B.1. 3-RM training loads at the first (filled) and last (open) training session in the power training group (n = 15). *Significant change (P ≤ 0.001).

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Appendix B

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Appendix C

APPENDIX C

Table C.2. Group characteristics

Power training Detraining Control

n 15 (6M,9F) 12 (5M,7F) 14 (5M,9F)

Age, y 72.9 (5.4) 72.7 (5.2) 69.1 (4.4)

Height, m 1.67 (0.10) 1.67 (0.10) 1.68 (0.08)

Mass, kg 73.6 (14.6) 73.7 (15.4) 73.9 (11.4)

BMI, kg/m2 _{25.8 (3.9)} _{26.0 (3.9)} _{25.5 (3.2)}

Values are Mean (±SD). M, male; F, female; BMI, Body Mass Index

Table C.1. Joint moment and power variables normalized to body mass and height before and after the control period (n = 14) at habitual and fast speeds.

Habitual Fast

Pre Post P Pre Post P

Joint moment, Nm/kg*m HM 0.42(0.08) 0.45(0.09) 0.263 0.77(0.15) 0.80(0.18) 0.347 KM 0.50(0.27) 0.51(0.17) 0.843 0.84(0.36) 0.86(0.22) 0.820 AM 0.94(0.13) 0.97(0.12) 0.251 0.91(0.15) 0.92(0.13) 0.522 Angular impulse, Nms/kg*m HM 0.05(0.02) 0.06(0.03) 0.511 0.07(0.02) 0.07(0.02) 0.480 KM 0.10(0.07) 0.09(0.04) 0.811 0.11(0.06) 0.12(0.05) 0.314 AM 0.42(0.07) 0.44(0.05) 0.030 0.40(0.06) 0.42(0.06) 0.137 Joint power, W/kg*m H1 0.30(0.15) 0.33(0.18) 0.632 0.59(0.25) 0.67(0.44) 0.547 K1 -0.77(0.63) -0.77(0.48) 0.992 -1.86(1.29) -1.86(0.9) 0.975 K2 0.61(0.58) 0.52(0.35) 0.367 1.37(0.83) 1.30(0.6) 0.647 A2 1.93(0.5) 1.99(0.39) 0.568 2.28(0.44) 2.44(0.36) 0.159 Joint work, J/kg*m TW 0.25(0.05) 0.26(0.07) 0.291 0.36(0.08) 0.39(0.11) 0.073 H1 0.04(0.03) 0.04(0.03) 0.588 0.06(0.04) 0.07(0.06) 0.596 K1 -0.05(0.04) -0.05(0.03) 0.701 -0.10(0.07) -0.10(0.06) 0.777 K2 0.06(0.06) 0.06(0.03) 0.328 0.11(0.07) 0.10(0.05) 0.465 A2 0.15(0.04) 0.16(0.03) 0.294 0.19(0.05) 0.22(0.06) 0.042 Values are Mean (±SD). HM; hip extensor moment in early stance, KM; knee extensor moment in early stance, AM; plantarflexor moment in late stance. H1; positive hip extensor power in early stance, K1; negative knee extensor power in early stance, K2; positive knee extensor power in mid-stance, A2; positive plantarflexor power in late stance. TW; Total positive work (See also Fig. 5.2). Significant P values are denoted in bold.

Table C.3. Gait velocity before and after power training (n = 15), detraining (n = 12), and control (n = 14) across all speeds

Habitual Fast Standardized

Pre Post P Pre Post P Pre Post P

Power training 1.32(0.16) 1.36(0.15) 0.220 1.85(0.28) 1.95(0.38) 0.026 1.24(0.05) 1.23(0.05) 0.217 Detraining 1.37(0.13) 1.32(0.21) 0.216 1.91(0.22) 2.00(0.25) 0.052 1.24(0.02) 1.23(0.30) 0.685 Control 1.35(0.14) 1.34(0.16) 0.652 1.97(0.35) 1.93(0.31) 0.526 1.25(0.03) 1.24(0.05) 0.313

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Appendix C

Table C.4. Coefficients of determination between muscle power and gait velocity at baseline (pre) and between changes in muscle power and changes in gait velocity (∆%) in the power training group (n=15)

Habitual gait velocity Fast gait velocity

Pre ∆% Pre ∆% R2 _P _R2 _P _R2 _P _R2 _P Knee extension 60°/s 0.310 0.031 0.002 0.882 0.461 0.005 0.006 0.779 120°/s 0.296 0.036 0.000 0.963 0.476 0.004 0.043 0.458 180°/s 0.292 0.038 0.024 0.584 0.402 0.011 0.059 0.382 Plantarflexor 20°/s 0.165 0.133 0.131 0.796 0.570 0.001 0.004 0.824 40°/s 0.215 0.081 0.100 0.252 0.487 0.004 0.008 0.757 60°/s 0.172 0.124 0.085 0.292 0.490 0.004 0.027 0.559

Significant P values are denoted in bold.

Table C.5. Coefficients of determination between joint work and gait velocity at baseline (pre) and between changes in joint work and changes in gait velocity (∆%) in the power training group (n = 15)

Habitual gait velocity Fast gait velocity

Pre ∆% Pre ∆%

R2 _P _R2 _P _R2 _P _R2 _P

H1 0.286 0.040 0.000 0.943 0.442 0.007 0.001 0.903

K2 0.358 0.018 0.008 0.745 0.501 0.003 0.018 0.628

A2 0.477 0.004 0.208 0.087 0.189 0.105 0.193 0.102

H1; positive hip extensor power in early stance, K2; positive knee extensor power in midstance, A2; positive plantarflexor power in late stance. Significant P values are denoted in bold.

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Appendix D

APPENDIX D

Summary (ENG)

Aging modifies locomotion: steps become shorter, cadence becomes higher, and walking speed slows. Aging also affects the mechanisms of walking and age-related mechanical plasticity of gait reflects a redistribution of lower extremity joint power output. Specifically, there is a distal to proximal shift in muscle function resulting in reduced ankle and increases hip power output in old compared with young adults walking at the same speed.

Maintaining adequate levels of gait velocity and delaying the onset of mobility impairments have become universal health care priorities. It is well documented that various types of exercise interventions can improve physical ability (i.e., muscle strength and power), along with gait velocity in old age. However, the underlying biomechanical mechanisms of how, if at all, training-induced improvements in physical ability become incorporated into old adults' gait and ultimately produce faster walking are unknown. To increase the efficacy of interventions that aim to improve locomotor performance and other critical mobility functions in old adults, there is a need for a paradigm shift from conventional outcome assessments (i.e., gait velocity) to more sophisticated, biomechanical measures (i.e. joint kinematics, kinetics, and neuromuscular activation).

This thesis aims to determine the biomechanical mechanisms of how exercise interventions, and in particular power training, improve gait velocity in old age. Power training (i.e., exercises against moderate heavy weights and with high movement velocities) compared with strength training (i.e., exercises against heavy weights with slow movement velocities) is a more effective training method for improving gait velocity in old age. Based on a literature review, candidate mechanisms for how strength or power training evoked adaptations in gait biomechanics that potentially underlie training-induced increases in old adults’ gait velocity are discussed (chapter 2). Subsequently, this thesis provides a detailed description of the design and methodology of the Potsdam Gait Study (POGS); a randomized controlled trial that examines the effects of 10 weeks of lower extremity power training on a series of biomechanical and neuromuscular outcome measures during level walking in old adults (chapter 3).

The second half of this thesis presents and discusses the results of POGS (chapters 4-6). Specifically, power training improved lower extremity muscle power and strength, on average, by 36%. Habitual gait velocity was unchanged after the intervention, but fast gait velocity improved by 6%. Stride and kinematic analyses revealed that higher cadence and reduced plantarflexor velocity during push-off underlie the training-induced improvements in fast gait velocity (chapter 4). Kinetic adaptations associated with changes in fast gait velocity included increased mechanical output around the hip joint and reduced mechanical output around the ankle joint (chapter 5). Power training-induced improvements in plantarflexor activation during push-off were associated with

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Appendix D

improvements in fast gait velocity (chapter 6).

Chapter 7 discusses the most important findings reported in this thesis. The large improvements in physical abilities (i.e., improved ankle muscle power) only limited transferred into gait. One explanation for the lack of incorporation of newly acquired muscle power into gait is perhaps the absence of an enabling mechanisms that allows the use of training-induced improvements in muscle power.

Overall, lower extremity power training is an effective method to improve lower extremity muscle strength and power, and to a lesser extent, gait velocity in healthy old adults. This thesis comprehensively studied power training-induced adaptations in gait biomechanics that potentially underlie increases in old adults’ gait velocity and revealed an important role for the hip muscles. In addition, improvements in plantarflexor activation during gait were associated with changes in fast gait velocity. Interventions that aim to improve gait velocity in healthy old adults should include exercises designed to improve hip and ankle muscle function, and to a lesser extend knee muscle function. Perhaps one way to increase the use of newly acquired physical abilities during gait it is to supplement the power training with functional training.

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Appendix E

APPENDIX E

Samenvatting (NL)

Veroudering beïnvloedt het lopen: stappen worden kleiner, cadans neemt toe, en loopsnelheid neemt af. Daarnaast beïnvloedt veroudering ook de manier van het lopen. Verouderingsgerelateerde mechanische plasticiteit van het lopen wordt gekenmerkt door een herverdeling van het vermogen rond de gewrichten van de onderste extremiteit. Er bestaat een distaal naar proximale verschuiving van spierfunctie wat resulteert in een verminderde output rond de enkel en een verhoogde output rond de heup bij ouderen in vergelijking met jongeren die op dezelfde snelheid lopen.

Het behoud van een adequate loopsnelheid en het uitstellen van mobiliteitsproblemen bij ouderen hebben prioriteit binnen de gezondheidszorg. Het is aangetoond dat verschillende soorten trainingsinterventies zowel de fysieke capaciteit (b.v., spierkracht en spierpower), als de loopsnelheid bij ouderen kunnen verbeteren. Echter, het onderliggende biomechanische mechanisme van of, en hoe, verbeterde fysieke capaciteit na een training wordt gebruikt tijdens lopen, wat uiteindelijk leidt tot een verbetering van de loopsnelheid bij ouderen, is onbekend. Om de doeltreffendheid van interventies die gericht zijn op het verbeteren van de loopsnelheid te vergroten, en daarbij de mobiliteit van ouderen te verhogen, is het nodig om naast loopsnelheid ook te kijken naar meer geavanceerde biomechanische uitkomstmaten tijdens het lopen, zoals gewrichtskinematica en -kinetica, en spieractivatie patronen.

Dit proefschrift richt zich op het achterhalen van de biomechanische mechanismen die ten grondslag liggen aan het verbeteren van de loopsnelheid bij ouderen na trainingsinterventies, in het bijzonder na een power-training interventie. Power training is een vorm van krachttraining waarbij gebruik wordt gemaakt van middelzware gewichten en hoge bewegingssnelheden. Power training bij ouderen verbetert de spierkracht, spierpower, evenals de loopsnelheid. Dit proefschrift bespreekt potentiele mechanismen van hoe kracht- of powertraining het gangbeeld en de loopsnelheid bij ouderen veranderen op basis van een literatuurstudie (hoofdstuk 2). Vervolgens geeft dit proefschrift een uitgebreide beschrijving van het ontwerp en de methodologie van de Potsdam Gait Study (POGS); een gerandomiseerd onderzoek met een controlegroep waarbij gekeken wordt naar de effecten van een 10-weekse power-training interventie op een reeks biomechanische en neuromusculaire uitkomstmaten tijdens lopen bij ouderen (hoofdstuk 3).

Het tweede deel van dit proefschrift presenteert en bespreekt de resultaten van POGS (hoofdstukken 4-6). De power training verbeterde de spierkracht van de onderste extremiteit met gemiddeld 36%. Voorkeursloopsnelheid was onveranderd na de training, maar de snelle loopsnelheid verbeterde met 6%. De analyses op schrede karakteristieken en gewrichtskinematica lieten zien dat hogere cadans en verminderde plantarflexor-snelheid tijdens de afzet waren gerelateerd aan de verbetering in snelle

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Appendix E

loopsnelheid (hoofdstuk 4). Kinetische aanpassingen die samenhangen met de verbeterde snelle loopsnelheid omvatten een verhoogde mechanische output rond het heupgewricht en een verminderde mechanische output rond het enkelgewricht (hoofdstuk 5). De door power training verbeterde spieractivatie van de plantarflexoren tijdens de afzet was geassocieerd met de verbetering van de snelle loopsnelheid.

Hoofdstuk 7 bediscussieert de belangrijkste bevindingen van dit proefschrift. Ondanks de grote toenamen in spierkracht en power na het volgen van de training gebruikten de ouderen hier weinig van tijdens het lopen. Een verklaring voor het gebrek van het opnemen van de door training verkregen extra spierpower tijdens het lopen is het ontbreken van een mechanisme dat de ouderen in staat stelt om de nieuwe spierpower te gebruiken tijdens het lopen.

Dit proefschrift laat zien dat power training een effectieve manier is om spierkracht en power, en in mindere mate loopsnelheid, te verbeteren bij gezonde ouderen. Dit proefschrift bestudeerde uitgebreid de effecten van power training op verschillende biomechanische aspecten van het looppatroon bij ouderen en laat zien dat de heup en kuitspieren een belangrijke rol spelen bij het sneller gaan lopen na de training. Trainingsinterventies die gericht zijn op het verbeteren van de loopschelheid bij ouderen moeten bestaan uit oefeningen die zijn ontworpen voor het verbeteren van de spierfunctie rond de heup- en enkel, en in mindere mate rond de knie. Om het gebruik van de door training opgebouwde spierkracht tijdens het lopen te bevorderen is het aan te raden om de powertraining aan te vullen met enkele functionele oefeningen.

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Appendix F

APPENDIX F

Curriculum Vitae

EDUCATION

Ph.D. Biomechanics and Aging, University of Groningen, 2017 MSc. Human Movement Sciences, University of Groningen, 2013 BSc. Human Movement Sciences, University of Groningen, 2011

PUBLICATIONS

Beijersbergen CM, Granacher U, Gäbler M, DeVita P, Hortobágyi T; Power

training-induced increases in muscle activation during gait in old adults, Med Sci Sports Exerc, under revision May 2017

Beijersbergen CM, Granacher U, Gäbler M, DeVita P, Hortobágyi T; Kinematic

mechanisms of how power training improves healthy old adults’ gait velocity, Med Sci Sports Exerc,2017; 52:338-344

Beijersbergen CM, Granacher U, Gäbler M, DeVita P, Hortobágyi T; Hip mechanics

underlie lower extremity power training-induced increase in old adults' fast gait velocity: The Potsdam Gait Study (POGS). Gait & Postures, 2017; 49(1):150-157

Waanders J, Beijersbergen CM, Murgia A, Hortobágyi T; Functional Relevance of Relative Maintenance of Maximal Eccentric Quadriceps Torque in Healthy Old Adults, Gerontology, 2016;62(6):588-596

Beijersbergen CM, Hortobágyi T, Beurskens, Lenzen-Großimlinhaus R, Gäbler M,

Granacher U; Design and protocol for a randomized controlled trial on the effects of power training on mobility and gait biomechanics in old adults with moderate mobility disability: the Potsdam Gait Study (POGS), Gerontology, 2016; 62(6):597-603

Beijersbergen CM, Granacher U, Vandervoort AA, DeVita P, Hortobágyi T; The

biomechanical mechanism of how strength and power training improves walking speed in old adults remains unknown. Aging Research Reviews, 2013; 12(2):618-27

INVITED TALKS

Beijersbergen CM, Hortobágyi T; Improved gait speed after exercise in old adults;

how does it work? 1st Network Meeting, University of Potsdam, Potdam, Germany, October 9 – 11, 2013

Hortobágyi T, Beijersbergen CM; Biomechanical mechanism of how interventions improve gait speed in aging. “Active Health: Movement is Health”, Humboldt University, Berlin, March 26-28 2015

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Appendix F

CONFERENCE PRESENTATIONS

Beijersbergen CM, Granacher U, Gäbler M, DeVita P, Hortobágyi T;Power training

increased neuromuscular activation of the extensor muscles during gait in old adults, American Society of Biomechanics, Boulder, August 8-11 2017

Tatarski RL, Brady R, Beijersbergen CM, Rider P, DeVita P, Hortobágyi T; Using a Force Platform and Inverse Dynamics to Identify Torque-Velocity and Power-Velocity Relationships in Healthy Old Adults. American Society of Biomechanics, Bostom, July 6-11 2014.

Beijersbergen CM, Tatarski RL, Rider P, Hortobágyi T, DeVita P; Strength training

failed to improve gait biomechanics in healthy old adults. 16th annual congress of the European College of Sport Science, Amsterdam, NL, July 2-5 2014

Beijersbergen CM; Tatarski RL, Domire ZJ, Rider P, Hortobágyi T, DeVita P; Changes

in Torque-Velocity relationship of the human plantarflexors in response to resistance training in old age. Human Movement Science Symposium, University of North Carolina, Chapel Hill, NC, March 1, 2013.

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Appendix g

APPENDIX G

Research Institute SHARE

This thesis is published within the Research Institute SHARE (Science in Healthy Ageing and healthcaRE) of the University Medical Center Groningen / University of Groningen. Further information regarding the institute and its research can be obtained from our internetsite: http://www.share.umcg.nl/. Most recent theses can be found in the list below. ((co-) supervisors are between brackets)

2017

Daud NAA

Paving ways for personalizing drug therapy during pregnancy; a focus on the risk of drug teratogenicity

(prof B Wilffert, dr JEH Bergman)

Spoorenberg SLW

Embracing the perspectives of older adults in organising and evaluating person-centred and integrated care

(prof SA Reijneveld, prof HPH Kremer, dr K Wynia)

Uittenbroek RJ

Impact of person-centered and integrated care for community-living older adults on quality of care and service use and costs

(prof SA Reijneveld, prof HPH Kremer, dr K Wynia)

Folbert E

Geriatric traumatology; the effectiveness of integrated orthogeriartric treatment on 1-year outcome in frail elderly with hip fracture

(prof JPJ Slaets, prof HJ ten Duis, dr JH Hegeman)

Panman CMCR & Wiegersma M

Pelvic organ prolapse; conservative treatments in primary care (prof MY Berger, dr JH Dekker)

Postema SG

Upper limb absence; effects on body functions and structures, musculoskeletal complaints and functional capacity

(prof CK van der Sluis, prof MF Reneman, dr RM Bongers)

Adrichem EJ van

Physical activity in recipients of solid organ transplantation (prof CP van der Schans, prof PU Dijkstra, dr R Dekker)

Luten KA

Development and evaluation of a community-based approach to promote healh-related behavior among older adults in a socioeconomically disadvantaged community

(prof A Dijkstra, prof SA Reijneveld, dr AF de Winter)

Setiawan D

HPV vaccination in Indonesia; a health-economic & comparative perspective (prof MJ Postma, prof B Wilffert, dr JA Thobari)

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Appendix G

Sluis A van der

Risk factors for injury in talented soccer and tennis players; a maturation-driven approach (prof C Visscher, dr MT Elferink-Gemser, dr MS Brink)

Bouwmans MEJ

A sad day’s night; the dynamic role of sleep in the context of major depression. (prof P de Jonge, prof AJ Oldehinkel)

Bakker M

Challenges in prenatal screening and diagnosis in the Netherlands (prof CM Bilardo, dr E Birnie)

Annema-de Jong JH

What’s on your mind? Emotions and perceptions of liver transplant candidates and recipients

(prof AV Ranchor, prof PF Roodbol, prof RJ Porte)

2016

Does HTJ van der

Enhancing performance & preventing injuries in team sport players (prof KAPM Lemmink, prof C Visscher, dr MS Brink)

Veldman K

Mental health from a life course perspective; the transition from school to work (prof U Bültmann, prof SA Reijneveld)

Mafirakureva N

Health economics of blood transfusion in Zimbabwe (prof MJ Postma, dr M van Hulst, dr S Khoza)

Mapako T

Risk modelling of transfusion transmissible infections (prof MJ Postma, dr M van Hulst)

Heuvel M van den

Developmental and behavioral problems in pediatric care; early identification (prof SA Reijneveld, dr DEMC Jansen, dr BCT Flapper)

Bonvanie IJ

Functional somatic symptoms in adolescence and young adults; personal vulnerabilities and external stressors

(prof JGM Rosmalen, prof AJ Oldehinkel, dr KAM Janssens)

Greeff JW de

Physically active academic lessons: effects on physical fitness and executive functions in primary school children