Force and Accuracy Throws by Older Adults: II

Journal of Aging and Physical Activity, 1993

Older adults threw tennis balls for force and accuracy to examine their adaptability to different task demands. Twenty-one (13 women, 8 men) participants were videotaped as they performed five force and five accuracy throws. The developmental level of each throw was determined; resultant ball velocities also were examined. Roberton's (1977, 1978) movement components were used in the former analysis. The typical pattern of gender differences occurred for both movement component and velocity measures. Men performed at higher levels than women. Only minor force versus accuracy differences were found in the movement patterns used by either men or women; none of these differences were significant. Clear task differences occurred for ball velocities. Men's forceful throws were faster than those for accuracy; women's throws did not differ for the two tasks. The generally lower developmental level of women's throws accounted for gender differences in velocity. Insufficient task differences may explain the lack of clear contrast in movement patterns.

The International Journal of Aging and Human Development, 1991

Previous investigations of the movement patterns of older adults have focused on functional movements. Performance declines have been reported with increasing age. Many investigations, however, do not require older adults to perform maximal, force producing actions. Smaller declines might be observed if older adults made a maximal effort. This investigation examined changes in a maximal skill—the overarm throw for force. Active, older adults were videotaped as they threw tennis balls. Thirteen people were filmed for two consecutive years. Gender and age differences were examined for movement patterns, ball velocity, and selected kinematic measures. Participants threw using patterns and velocities generally observed in children in middle elementary-school years. This result suggested there was a decline in this force production skill. Some older adults regressed in the movement patterns they used over the two years of testing. Older males threw faster, using more advanced movement pa...

Age and Ageing, 2006

Objective: to examine the plasticity of motor performance in old age. Older adults were instructed and trained in a juggling task and their performances were compared, first, within the group of older adults and, second, with the performances of children, youths and younger adults. Subjects: older adults, children, youths and younger adults (n = 1,206, range 6-89 years). Methods: participants were asked to learn a juggling task. Performance was tested before semantic instruction (pre-test 1), after semantic instruction (pre-test 2) and after 6 days of juggling practice (post-test). None of the participants had prior experiences in juggling. Results were analysed using repeated measure analysis of variance (ANOVA). Results: older adults showed a clear improvement in juggling performance after instruction and after six training sessions. On average, they reached performances comparable with those of children aged between 10 and 14 years, and with those of younger adults aged between 30 and 59 years. Only youths and younger adults aged between 15 and 29 years showed significantly higher performances at baseline, after instruction and after training. Conclusions: older adults exhibit high reserve capacity, that is, a potential for learning 'new' motor skills.

Gait & Posture, 2011

Functional dependence and falls are among the most serious and common problems encountered by older adults. Twenty percent of community-dwelling older adults in the U.S. reported having difficulty performing activities of daily living and the rate of problems increases with advancing age [1]. Approximately 30% older adults report having fallen one or more times each year [2], and 10-15% among them suffered from serious injuries [3]. Both problems described above are associated with further deterioration of functional capacity, falling, premature institutionalization, reduced quality of life, and heightened mortality [4,5]. One of the known contributing factors to functional decline and increased risk of falling in old age is balance impairment. It has been revealed that self-report of imbalance [6], poorer clinical balance performance [7], and changes in biomechanical measures reflecting postural stability [8] or postural responses to external perturbations [9] are associated with aging. Therefore, a better understanding in balance control in old age may help to reduce functional decline and risk of falling. Forward reach is a frequently performed activity of daily living. The task requires moving the body's center of mass toward the front edge of the base of support in a well controlled manner, and thus is often regarded as an indicator of boundary of stability [10]. Reach distance, the distance between the resting and farthest hand positions, is used widely in clinics and research to reflect balance ability and found to be related to frailty [11], risk of falling [12,13], and the ability to perform functional tasks in older adults [11]. When reaching forward, older adults have been shown to have shorter absolute reach distance than young adults [10,14-16]. Although this coincides with the general belief that older adults are limited in their balance capacity, the findings are not conclusive. Several studies have reported a positive correlation between reach distance and body height [10,16-18]. It is thus probable that the observed age-related reduction in reach distance in the above studies could partly be attributed to a tendency of shorter stature in the older adults [10,14-16]. Furthermore, older adults tend to adopt a more forward inclined posture during quiet standing [19]. Adopting such an initial posture during forward reach can put the hand in a more anterior position, such that a shorter reach distance would be calculated even when the farthest hand position is the same. The influence of initial posture on task performance can be indirectly supported by the findings that ''old'' older adults (over 80 years old) did not differ from their younger counterparts (65-79

Journal of Strength and Conditioning Research, 2011

Practitioners training the older adult may benefit from a low-cost, easy-to-administer field test of upper body power. This study evaluated validity and reliability of the seated medicine ball throw (SMBT) in older adults. Subjects (n = 33; age 72.4 6 5.2 years) completed 6 trials of an SMBT in each of 2 testing days and 2 ball masses (1.5 and 3.0 kg). Subjects also completed 6 trials of an explosive push-up (EPU) on a force plate over 2 testing days. Validity was assessed via a Pearson Product-Moment correlation (PPM) between SMBT and EPU maximal vertical force. Reliability of the SMBT was determined using PPMs (r), Intraclass correlation (ICC, R) and Bland-Altman plots (BAPs). For validity, the association between the SMBT and the EPU revealed a PPM of r = 0.641 and r = 0.614 for the 1.5-and 3.0-kg medicine balls, respectively. Test-retest reliability of the 1.5-and 3.0-kg SMBT was r = 0.967 and r = 0.958, respectively. The ICC values of the 1.5-and 3.0-kg SMBT were R = 0.994 and 0.989, respectively. The BAPs revealed 94% of the differences between day 1 and 2 scores were within the 95% confidence interval of the mean difference. Test-retest reliability for the EPU was r = 0.944, R = 0.969. The BAPs showed 94% of the differences between day 1 and 2 scores were within the 95% confidence interval of the mean difference, for both medicine ball throws. In conclusion, for the older adult, the SMBT appears to be highly reliable test of upper body power. Its validity relative to the maximal force exerted during the EPU is modest. The SMBT is an inexpensive, safe, and repeatable measure of upper body power for the older adult.

Human Movement Science, 2012

In team-handball, skilled athletes are able to adapt to different game situations that may lead to differences in movement variability. Whether movement variability affects the performance of a team-handball throw and is affected by different skill levels or throwing techniques has not yet been demonstrated. Consequently, the aims of the study were to determine differences in performance and movement variability for several throwing techniques in different phases of the throwing movement, and of different skill levels. Twenty-four team-handball players of different skill levels (n = 8) performed 30 throws using various throwing techniques. Upper body kinematics was measured via an 8 camera Vicon motion capture system and movement variability was calculated. Results indicated an increase in movement variability in the distal joint movements during the acceleration phase. In addition, there was a decrease in movement variability in highly skilled and skilled players in the standing throw with run-up, which indicated an increase in the ball release speed, which was highest when using this throwing technique. We assert that team-handball players had the ability to compensate an increase in movement variability in the acceleration phase to throw accurately, and skilled players were able to control the movement, although movement variability decreased in the standing throw with run-up.

The Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 2002

Fifteen older adults ( M ϭ 68 years old) and 15 young adults ( M ϭ 23 years old) participated in a speed-accuracy task in which aiming movements were performed on a digitizing tablet to assess movement slowing and variability in older adults. Target-size and movement amplitude influences were analyzed separately to determine if they affected the performance of the young and older adults differently. When target size was increased, older adults did not increase the relative distance traveled in the primary submovement. When movement amplitude was increased, older adults did not scale movement velocities to the same magnitude as young adults did. Both the inability to scale velocity and the inability to increase the relative distance traveled in the primary submovement contribute to slower, more variable movements observed in older adults depending on task parameters. Thus, these data reveal that manipulation of target size and movement amplitude yield two distinct factors that contribute to slowness of movement in older adults.

2006

Background: In the past, several research groups have shown that when a velocity dependent force field is applied during upper limb movements subjects are able to deal with this external perturbation after some training. This adaptation is achieved by creating a new internal model which is included in the normal unperturbed motor commands to achieve good performance. The efficiency of this motor control mechanism can be compromised by pathological disorders or by muscular-skeletal modifications such as the ones due to the natural aging process. In this respect, the present study aimed at identifying the age-related modifications of upper limb motor control strategies during adaptation and de-adaptation processes in velocity dependent force fields. Methods: Eight young and eight elderly healthy subjects were included in the experiment. Subjects were instructed to perform pointing movements in the horizontal plane both in a null field and in a velocity dependent force field. The evolution of smoothness and hand path were used to characterize the performance of the subjects. Furthermore, the ability of modulating the interactive torque has been used as a paradigm to explain the observed discoordinated patterns during the adaptation process. Results: The evolution of the kinematics during the experiments highlights important behavioural differences between the two groups during the adaptation and de-adaptation processes. In young subjects the improvement of movement smoothness was in accordance with the expected learning trend related to the consolidation of the internal model. On the contrary, elders did not show a coherent learning process. The kinetic analysis pointed out the presence of different strategies for the compensation of the external perturbation: older people required an increased involvement of the shoulder with a different modulation of joint torque components during the evolution of the experiments. Conclusion: The results obtained with the present study seem to confirm the presence of different adaptation mechanisms in young and senior subjects. The strategy adopted by young subjects was to first minimize hand path errors with a secondary process that is consistent with the optimization of the effort. Elderly subjects instead, seemed to shift the importance of the two processes involved in the control loop slowing the mechanism optimizing kinematic performance and enabling more the dynamic adaptation mechanism.

Japanese Psychological Research, 2000

The purpose of this investigation was to analyze the differences in general and specific throwing capacity of handball players as a function of the age category. Differences between throwing velocity to goal without and with opposition have also been addressed. Ninety four handball senior and U-18 players were assessed in four different situations of throwing: 1) heavy medicine ball throw, 2) light medicine ball throw, 3) throwing velocity without opposition and 4) throwing velocity with opposition. Senior players were found to perform far better than the U-18 players in all four throwing situations (p<0.001; t1=6.958; t2=8.244; t3=8.059; t4=5.399; df=92).Throwing velocity was higher without than with opposition for both groups; the throwing velocity of the senior group was 7.79% lower (p<0.01; t=8.317; df=47) when there was opposition, whereas U-18 players' velocity lowered by 6.03% (p<0.01; t=4.469; df=45). The results suggest that age can be a determining factor in h...