The Effects of Knee Joint Pain and Disorders on Knee Extension Strength and Walking Ability in the Female Elderly

doi:10.4236/ape.2012.24024

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Advances in Physical Education

2012. Vol.2, No.4, 139-143

Published Online November 2012 in SciRes (http://www.SciRP.org/journal/ape) http://dx.doi.org/10.4236/ape.2012.24024

The Effects of Knee Joint Pain and Disorders on Knee Extension

Strength and Walking Ability in the Female Elderly

Hiroki Sugiu ra, Shinichi Dem ura

Graduate School of Natural Science & Technology, Kanazawa Unive rs i ty, Kanazawa, Japan

Email: [email protected], [email protected]

Received August 4th, 2012; revised September 8th, 20 12 ; a cce pte d S ep tember 20th, 2012

This study examines the differences in leg strength and walking ability among groups with different knee

problems. The participants were 328 elderly females (60 - 94 years old; mean age 76.1 years; SD = 6.2)

who were classified into three groups: those without knee pain or a knee disorder, those with knee pain,

and those with a knee disorder. The subjects took knee extension strength and 12 meter maximum effort

walk tests. Knee extension strength was significantly lower in the groups with knee pain and a knee dis-

order than in the group without pain or a knee disorder. Walking speed was significantly slower in the

group with a knee disorder than in the other two groups. In conclusion, the female elderly with knee pain

or a knee disorder are inferior in knee extension strength and walking ability. In addition, the elderly with

a knee disorder are inferior in walking ability to the elderly with knee pain.

Keywords: Knee Joint Pain; Knee Joint Disorder; Knee Extension Strength; Gait; Female Elderly

Introduction

Walking is the most basic movement in daily life (Pratt,

1994). Leg strength, balance and leg joint functions are impor-

tant factors related to walking. These physical functions de-

crease with age, and thus walking ability also decreases with

age. As a result, the frequency of daily life activities is limited

markedly, and there is also a decrease in the ability to perform

activities of daily life (ADL) (Jochanan et al., 2009; Hurley et

al., 1998). In addition, a decrease in walking ability also in-

creases fall occurrences (Mary & Tinetti, 2003), which there-

fore greatly reduces quality of life (Sato et al., 2007; Suzuki et

al., 2002). Hence, it is very important to prevent a decrease in

walking functions in order to maintain independent daily life in

the elderly.

Knee joints have the maximum load capacity of all the leg

joints, and they play a very important role in walking (Kuro-

kawa et al., 2001). Recently, more knee disorders have been

found in the elderly (Peat et al., 2001). Tennant et al. (1995)

reported that 8% of the elderly have them. Leg strength de-

creases with age in the elderly years (Frontera et al., 1991;

Murrary et al., 1985), and the elderly with leg joint disorders

are greatly limited in walking, due to both the knee disorder and

a decrease in leg strength (Zeni & Higginson, 2009; Zoltan et

al., 2006). Hence, the active mass of the elderly with knee dis-

orders decreases markedly, subsequently causing a rapid de-

crease in leg strength (Kirsten, 2009).

Kirsten (2009) reported that subjects with a knee disorder

were inferior in walking speed, stance stability and accelerating

force. Berman et al. (1987) and Andriacchi et al. (1982) re-

ported that the elderly requiring knee arthroplasty are inferior in

walking speed, stance time, step length and cadence, as com-

pared to the general elderly.

On the other hand, there are many older people with subjec-

tive knee pain, even though they do not have a serious knee

disorder (Zoltan et al., 2006; Al-Zaharni & Bakheit, 2002; Peat

et al., 2001). They can be regarded as an auxiliary group to

people with a knee disorder. Alindon et al. (1992) and Urwin et

al. (1998) reported that about 20% of the elderly had knee pain.

Sugiura & Demura (2012) reported that the group with knee

pain was inferior in knee extension strength to the group with-

out knee pain, and the group with pain in both knees was infe-

rior in stride length and step length to the group without knee

pain.

From the above, it is considered that the elderly with a knee

disorder or knee pain are inferior in leg strength and walking

ability to those without a knee disorder or pain. On the other

hand, it is assumed that knee disorder participants with a spe-

cific knee disorder are inferior in leg strength and/or walking

ability to the people with knee pain, who are the reserve group

of subjects with a knee disorder.

The prevalence of knee pain and knee disorders is high in the

female elderly (Oida & Nakamura, 2008; Peat et al., 2001).

This study examines the differences in knee extension strength

and walking ability among female elderly, who are divided into

three groups: those without knee pain or a knee disorder, those

with knee pain, and those with knee disorders.

Methods

Subjects

Subjects consisted of 328 female elderly people (60 - 94

years old; mean age 76.1 years; SD = 6.2), who which classi-

fied into the following three groups: 168 persons without knee

pain or disorder (knee non-pain and disorder group), 116 per-

sons with subjective knee pain (one knee pain group, n = 75;

both knees in pain group, n = 41), and 44 persons with a knee

disorder (one knee disorder group, n = 21; both knees disorder

group, n = 23). Forty persons in the knee pain group and 11

persons in the knee disorder group had right knee pain. The

knee pain and the knee disorder were grouped by Japanese

H. SUGIURA, S. DEMURA

edition knee function scale (Hashimoto et al., 2003) that con-

formed to made WOMAC (Bellamy et al., 1988), and the

cut-off point was set at 210 points (Oida & Nakamura, 2008).

In addition, the elderly with knee disorders were largely divided

into persons who can achieve activities of daily living (ADL)

independently and persons who cannot due to disorders. The

participants regularly visit a hospital for treatment of the knee

disorders, but could perform ADL independently. If the knee

disorder elderly in this study are inferior in walking ability to

the other two groups, it is also assumed that those with a knee

disorder and who cannot perform ADL independently are infe-

rior to them. Table 1 shows the basic statistics of age, height,

and body weight according to each group.

All subjects participated in health classes or social educa-

tional activities hosted by municipal governments, and they

engaged in social activities at least once per week or on alter-

nate weeks. Before the measurements, the purpose and proce-

dure of this study were explained to all of the subjects in de-

tail and informed consent was obtained. The present experi-

mental protocol was approved in advance by the ethics com-

mittee (Kanazawa University Health & Science Ethics commit-

tee).

Leg Strength

To evaluate leg strength, knee extension strength was se-

lected since it is strongly affected by knee pain or disorder (Su-

giura & Demura, 2012; Astephen et al., 2008). During meas-

urement of isometric knee extension strength, the subjects were

seated upright in a rigid chair with the knee flexed at a 90° an-

gle with the lower legs strapped by a pad just above the ankle,

attached by a backward rigid bar to a tension meter attachment

(T.K.K.1269f; Takei Scientific Instruments Co. Ltd., Japan). In

addition, the subjects folded their arms across their chest. A

tester held the pad in place so it would not move, and then

asked the subjects to extend the knee as far as possible and to

maintain it for 3 seconds. Leg strength was measured twice and

the sum of the mean of right and left values was used as a pa-

rameter.

Walking Ability

Gait properties were measured with a gait analysis system

(Walk Way MG-1000, Anima, Japan). The MG-1000 with plate

sensors determines time, dimensions, and the distance of the

foot when the foot touches the sheet surface, and it can measure

grounding/non-grounding on the bearing surface as an on/off

signal. Data were recorded into a personal computer at 100 Hz.

The posture and movement during the measurement were ex-

plained to the subjects before the measurement. The walkway

was 12 meters in length. The subjects walked straight for 12

meters as fast as possible. Data from the middle 5 meter portion,

excluding the first 3 meters and the final 4 meters, were used

for analysis (Figure 1). Walking speed, which is the walking

distance per second, was selected as the indicator of walking

ability.

Statistical Analysis

The intra-class correlation coefficient (ICC) was calculated

to examine the test-retest reliability of knee extension strength.

body weight as a covariate. A Scheffe’s test was used for a

0m 3m7.8m12m

Walkway

4.8m

goalstart 1m

Figure 1.

Setting of WalkWay MG-1000.

Each parameter was examined by ANCOVA with multiple

comparison test if ANCOVA showed a significant difference.

The significance level in this study was set at p < 0.05.

Results

Table 1 shows the basic statistics of age, height and body

weight in the knee non-pain and disorder (G1), one knee pain

(G2), both knees pain (G3), one knee disorder (G4) and both

knees disorder (G5) groups, and the test results among their

means. The result of one-way ANOVA showed a significant

difference only in weight. A linear comparison test of the knee

non-pain and disorder (G1), knee pain (G2 + G3) and disorder

(G4 + G5) groups showed that the knee disorder group is sig-

nificantly heavier than the knee non-pain and disorder group.

Additionally, the body weight between the one knee and the

both knees pain groups, and between the one knee and the both

knees disorder groups showed an insignificant difference.

The ICC of the knee extension strength was very high (right:

0.93; left: 0.92; both: 0.90). Table 2 shows the basic statistics

and test results of knee extension strength in the above five

groups. The result of ANCOVA showed a significant difference.

A linear comparison test showed that the knee pain and knee

disorder groups are significantly inferior in knee extension

strength to the group without knee pain or disorder. Addition-

ally, the knee extension strength between the one knee and the

both knees pain groups, and between the one knee and the both

knees disorder groups showed an insignificant difference.

Table 3 shows basic statistics and test results of walking

speed in the above five groups. The result of ANCOVA showed

a significant difference. A linear comparison test showed that

the knee disorder group is significantly inferior in walking

speed to the knee non-pain and disorder and the knee pain

groups. Additionally, the one knee disorder and the both knees

disorder groups are significantly inferior in walking speed to

the knee non-pain and disorder group, but a significant differ-

ence was not found between the one knee and both knees pain

groups and between the one knee and both knees disorder

groups.

Table 4 shows basic statistics and test results from means of

the above 5 groups for gait parameters. The result of ANCOVA

showed a significant difference in stance time, stride length,

step length, step width, swing speed and cadence. In a linear

comparison test, significant differences were found in the

stance time, step width, swing speed and cadence between the

knee disorder group and both the knee non-pain and disorder

and the knee pain groups. Stride length and step length are sig-

nificantly shorter in the groups with knee pain and disorder

than in the group without knee pain or disorder. Overall, gait

parameters showed significant differences between the one knee

disorder and the both knees disorder group, as well as the

140

H. SUGIURA, S. DEMURA

Table 1.

The mean difference am ong groups for age, height and body weight.

Knee non-pain

and disorder

(G1: n = 168)

One knee pain

(G2: n = 75) Both knees pain

(G3: n = 41) One knee disorder

(G4: n = 21) Both knees disorder

(G5: n = 23) ANOVA Scheff’s post-hoc

M SD max min M SD max min M SD max min MSD max min MSD max min F p G1, (G2 + G3),

(G4 + G5)

Age

(yr) 74.3 6.8 87 62 76.9 5.9 94 66 76.5 4.7866876.85.2876976.95.685 65 2.25 0.07 -

Height

(cm) 148.1 6.1 164.5 131.6 147.3 6.0 161.4 132.5 147.6 5.6158.8138.4148.85.0156.0138.0146.94.1157.6 142.0 0.37 0.83 -

Weight

(kg) 48.27 7.25 68.7 34.2 49.22 8.41 70.9 32.5 52.41 5.3365.443.554.807.2871.039.052.516.7068.8 43.0 4.11 0.00* G1 < (G4 + G5)

Note: *p < 0.05.

Table 2.

Difference in knee extension str ength among groups.

Knee non-pain

and disorder

(G1: n = 168)

One knee pain

(G2: n = 75) Both knees pain

(G3: n = 41) One knee disorder

(G4: n = 21) Both knees disorder

(G5: n = 23) ANCOVA Scheff’s post-hoc

M SD max min M SD max min M SDmax min MSD max minMSD max min F p G1, (G2 + G3),

(G4 + G5)

Knee

extension

strength

(kg)

14.85 3.97 26.90 7.52 12.69 3.78 22.47 4. 06 12. 45 3.5816.935.9111.183.2017.345.8810.344.5118.25 3.34 9.01 0.00* (G2 + G3),

(G4 + G5) < G 1

Note: *p < 0.05.

Table 3.

Difference in walking speed among groups.

Knee non-pain

and disorder

(G1: n = 168)

One knee pain

(G2: n = 75) Both knees pain

(G3: n = 41) One knee disorder

(G4: n = 21) Both knees disorder

(G5: n = 23) ANCOVA Scheff’s

post-hoc

M SD max min MSD max min MSD max min MSD max min MSD max min F p G1,

(G2 + G3),

(G4 + G5)

Walking

speed

(cm/s) 177. 7 28.0 240.5 110.8 162. 224.6 236.1 103.7 164. 528.6221. 0106.4142.331.6207.080.1134.131.4 190.6 69.6 9.35 0.00*(G4 +

G5) < G1,

(G2 + G3)

Note: *p < 0.05.

knee non-pain and disorder group. How- ever, significant dif-

ferences were not found between the one knee and both knees

pain groups, and between the one knee and both knees disorder

groups.

Discussion

The knee disorder group had a higher body weight than the

knee non-pain and disorder group. Yoshimura et al. (2004) and

Oliveria et al. (1999) reported that a knee disorder contributes

to a burden increase to knee joints due to a weight increase. In

older age, because leg strength decreases markedly with age

(Frontera et al., 1991; Murrary et al., 1985), the durability of

knee joints is considered to also decrease with age. Sugiura &

Demura (2012) reported that being overweight can contribute to

knee pain in old age. It is believed that active mass decreases

due to knee pain, thus increasing body weight, and because of

the extra burden on knee joints, knee pain may worsen into a

disorder. From the present results, it is concluded that the

heavier body weight of the knee disorder people may be largely

attributed to a limited active mass due to the disorder.

The knee pain and knee disorder groups were inferior in knee

extension strength to the group without knee pain or a disorder,

but an insignificant difference was found between the knee pain

and knee disorder groups. In short, although it was hypothe-

sized that the knee disorder group is inferior in knee extension

strength to the knee pain group, this hypothesis was rejected. It

now thought that the knee disorder subjects in this study could

walk independently (see Subjects in Method); therefore, they

could exert leg strength by enduring pain. The elderly who

cannot walk independently could find it difficult to exert leg

strength maximally, and their leg strength may be inferior to

that of the knee pain people. In any case, it was found that the

participants with knee pain and disorders are inferior in knee

extension strength. On the other hand, the knee extension

strength showed an insignifican difference between the one t

H. SUGIURA, S. DEMURA

Table 4.

Difference in gait parameters among groups.

Knee non-pain

and disorder

(G1: n = 168)

One knee pain

(G2: n = 75) Both knees pain

(G3: n = 41) O ne knee disorde r

(G4: n = 21) Both knees disorder

(G5: n = 23) ANCOVA Scheff’s

post-hoc

M SD max min M SD max min MSDmax min MSD max min MSD max min F p G1,

(G2 + G3),

(G4 + G5)

Stance

time (s) 0.43 0.06 0.58 0.30 0.450.06 0.63 0.35 0.430.060.580.320.510.090.720.360.510.060.65 0.42 7.34 0.00* G1, (G2 +

G3) <

(G4 + G5)

Swing

time (s) 0.34 0.03 0.43 0.23 0.340.03 0.42 0.27 0.320.030.380.260.350.030.410.280.350.030.41 0.29 2.35 0.07 -

Stride

length

(cm) 133.3 16.3 172.5 86.5 125.514.9 156.8 86.8 120.817.1153.383.7118.815.5146.176.4113. 220.7151.1 58.4 6.39 0.00* (G2 + G3),

(G4 + G5) <

Step

length

(cm) 66.32 8.06 85.67 42.70 62.347.45 78.42 43.00 60.228.6076.1741.5258.877.4672.6338.8056.3010.3675.29 29.32 6.44 0.00* (G2 + G3),

(G4 + G5) <

Step

width (cm) 7.16 2.42 13.13 1. 00 7.022.02 11.64 3.50 7.762.3212.844.759.153.5815. 503.388.872.6813.75 2.84 3.55 0.01* G1, (G2 +

G3) <

(G4 + G5)

Swing

speed

(cm/s) 399.5 48.8 508.3 254.7 376. 849.2 522.5 256.8 377.655.4478.9265.7343.560.5475.1221.7325.664. 6439. 1 202.5 7.48 0.00* (G4 + G5) <

G1, (G2 + G3)

Cadence

(steps/min) 161.1 18.3 218.2 123.9 156. 316.8 191.5 114.4 162.518.5210.0125.4144.220.8185.6110.1142.913. 6172. 8 115.4 5.09 0.00* (G4 + G 5) <

G1, (G2 + G3)

Note: Stance time is the duration that th e body is supported b y one foot, that is, the phase in which one foot contacts the flo or. Swing time is the duration th at one foot

swings, that is , whi le one foot is rai sed off the floor. St rid e length is th e length of t wo cons ecut iv e steps . St ep l ength is the distance between anterior-posterior patterns (one

step length ). St ep widt h is the dist ance between bot h feet . Swing speed is the speed when subjects extend a leg forward in the stride length. Cadence is the number of steps

per minute . *p < 0.05.

knee and the both knees pain groups, and between the one knee

and the both knees disorder groups. Since they can walk inde-

pendently, it is inferred that they can also exert leg strength

while enduring pain.

Walking speed is generally used as an index of the walking

ability (Astephen et al., 2008; Nakazawa, 2010). Suzuki (2009)

reported that 31.1% of the elderly with walking speeds less than

120 cm/s have geriatric syndrome (falls, urinary incontinence,

malnutrition, depression). Thus, it is important to prevent a

decrease in walking speed to continue living independently

(Nakazawa, 2010). The present results show that walking speed

of the knee disorder group is slower than that of the other two

groups. Astephen et al. (2008) reported a similar result. It is

inferred that the knee disorder people are inferior in walking

ability. As stated before, a difference in the knee extension

strength between the knee pain group and the knee disorder

group was not found in this study. Since knee extension

strength was measured in a seated position, body weight did not

burden the knee joint. In contrast, during walking, the full

weight is a burden on the knee joints. Other physical fitness

factors (e.g., balance ability) also affect walking. Therefore,

although there was no significant difference in knee extension

strength between both groups, the knee disorder group is con-

cluded to have been slower than the knee pain group in walking

speed, due to the larger body weight burden on the knee.

Sugiura & Demura (2012) reported that there was no signifi-

cant difference in gait between the one knee pain people and

the both knees pain people. In addition to the above, it was also

confirmed in this study that there is no significant difference in

the gait of the one knee disorder people and both knees disorder

people. The knee disorder people in this study do not have pa-

ralysis and/or rheumatism in the lower limbs (Nakazawa, 2010;

Maruyama, 2003), which make stable gait difficult, and they

could walk independently (see Subjects in Method). The elderly

who can walk independently can exert leg strength to some

extent, regardless of whether one or both knees have pain or a

disorder. Hence, their gait showed little difference.

If walking speed is inferior, the gait is also assumed to be

different. The results presented here suggest that stance time,

step width, swing speed and cadence of knee disorder people

are different from the knee pain people and people without knee

pain or a disorder. In addition, the stride and step length of the

knee pain and disorder people were shorter. Kirsten (2009)

reported that because elderly with knee disorders bend their

knee joints during the swing phase, their step length is shorter

than that of the elderly without knee pain or disorder. Morrison

(1970) reported that during the in stance phase of a maximum

velocity walk, a load equaling quadruple the body weight im-

poses on the knee joint. Hence, it is concluded that a large load

burdens the knee joints during the in stance phase for individu-

als with knee pain or disorders. On the other hand, Demura et al.

(2011) and Patla (1997) reported that the gait change of the

elderly is a kind of strategy to maintain stability during walking.

In short, a decrease in stride and step length may be a walk

strategy to reduce the burden on the knee joints for elderly with

knee pain and disorders. As already stated, more gait parame-

142

H. SUGIURA, S. DEMURA

ters (stance time, step width, swing speed and cadence) showed

significant differences between the knee disorder group and the

knee pain group. It is inferred that the knee disorder individuals

establish a strategy to maintain walking stability, rather than

trying to walk quickly.

It is necessary to further examine ability to achieve activities

of daily living other than walking in the female elderly with

knee pain and disorder.

Conclusion

In conclusion, the female elderly with knee pain and/or dis-

orders are inferior in knee extension strength and walk ability to

the elderly without knee pain or disorder. In addition, the fe-

male elderly with knee disorders are inferior in walking ability

to the elderly with knee pain.

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