Gait Biomechanics

Gait Biomechanics, Spatial and Temporal Characteristics, and the Energy Cost of Walking in Older Adults With Impaired Mobilityfrom Physical Therapy current issue by Wert, D. M., Brach, J., Perera, S., VanSwearingen, J. M.

Background
Abnormalities of gait and changes in posture during walking are more common in older adults than in young adults and may contribute to an increase in the energy expended for walking.

Objective
The objective of this study was to examine the contributions of abnormalities of gait biomechanics (hip extension, trunk flexion, and foot-floor angle at heel-strike) and gait characteristics (step width, stance time, and cadence) to the energy cost of walking in older adults with impaired mobility.

Design
A cross-sectional design was used.

Methods
Gait speed, step width, stance time, and cadence were derived during walking on an instrumented walkway. Trunk flexion, hip extension, and foot-floor angle at heel contact were assessed during overground walking. The energy cost of walking was determined from oxygen consumption data collected during treadmill walking. All measurements were collected at the participants' usual, self-selected walking speed.

Results
Fifty community-dwelling older adults with slow and variable gait participated. Hip extension, trunk flexion, and step width were factors related to the energy cost of walking. Hip extension, step width, and cadence were the only gait measures beyond age and gait speed that provided additional contributions to the variance of the energy cost, with mean R2 changes of .22, .12, and .07, respectively.

Limitations
Other factors not investigated in this study (interactions among variables, psychosocial factors, muscle strength [force-generating capacity], range of motion, body composition, and resting metabolic rate) may further explain the greater energy cost of walking in older adults with slow and variable gait.

Conclusions
Closer inspection of hip extension, step width, and cadence during physical therapy gait assessments may assist physical therapists in recognizing factors that contribute to the greater energy cost of walking in older adults.

Dr. Joshua Brooks,
Chiropractor Fairfax, VA 22031
Chiropractor Alexandria, VA 22304

Relationships Among Balance, Visual Search, and Lacrosse-Shot Accuracy

Relationships Among Balance, Visual Search, and Lacrosse-Shot Accuracy

Marsh, DW, Richard, LA, Verre, AB, and Myers, J. Relationships among balance, visual search, and lacrosse-shot accuracy. J Strength Cond Res 24(6): 1507-1514, 2010-The purpose of this study was to examine variables that may contribute to shot accuracy in women's college lacrosse. A convenience sample of 15 healthy women's National Collegiate Athletic Association Division III College lacrosse players aged 18-23 (mean +/- SD, 20.27 +/- 1.67) participated in the study. Four experimental variables were examined: balance, visual search, hand grip strength, and shoulder joint position sense. Balance was measured by the Biodex Stability System (BSS), and visual search was measured by the Trail-Making Test Part A (TMTA) and Trail-Making Test Part B (TMTB). Hand-grip strength was measured by a standard hand dynamometer, and shoulder joint position sense was measured using a modified inclinometer. All measures were taken in an indoor setting. These experimental variables were then compared with lacrosse-shot error that was measured indoors using a high-speed video camera recorder and a specialized L-shaped apparatus. A Stalker radar gun measured lacrosse-shot velocity. The mean lacrosse-shot error was 15.17 cm with a mean lacrosse-shot velocity of 17.14 m[middle dot]s-1 (38.35 mph). Lower scores on the BSS level 8 eyes open (BSS L8 E/O) test and TMTB were positively related to less lacrosse-shot error (r = 0.760, p = 0.011) and (r = 0.519, p = 0.048), respectively. Relations were not significant between lacrosse-shot error and grip strength (r = 0.191, p = 0.496), lacrosse-shot error and BSS level 8 eyes closed (BSS L8 E/C) (r = 0.501, p = 0.102), lacrosse-shot error and BSS level 4 eyes open (BSS L4 E/O) (r = 0.313, p = 0.378), lacrosse-shot error and BSS level 4 eyes closed (BSS L4 E/C) (r = -0.029, p = 0.936) lacrosse-shot error and shoulder joint position sense (r = -0.509, p = 0.055) and between lacrosse-shot error and TMTA (r = 0.375, p = 0.168). The results reveal that greater levels of shot accuracy may be related to greater levels of visual search and balance ability in women college lacrosse athletes. (C) 2010 National Strength and Conditioning Association