Semi-Recumbent Vibration Therapy in Older Adults

The primary aim of this pilot is to examine the effect of vibration therapy on muscle function. Weight corrected jump power will be the main outcome variable. Countermovement jumps are performed on a Leonardo force plate (Novotec Medical, Pforzheim, Germany) following standard procedures. Jumping mechanography uses maximal countermovement jumps to quantitatively measure muscle strength in the legs. Participants will be asked to perform three countermovement jumps. Participants are asked to try to jump as high as possible using both legs. Three jumps are performed; the jump with the highest jump height is used for analysis.

Grip Strengthwas acquired using a JAMAR hand dynamometer in the routine clinical manner. Measurements were recorded using participants' non-dominant hand and repeated 3 times to determine maximum grip strength.

Gait speed will be measured by instructing participants to walk four meters at their normal pace; they are timed with a stopwatch. This test will be repeated twice. The walk performed in the least time will be utilized for scoring purposes.

Sway is assessed by having the participants stand with feet being placed side by side for ten seconds. Participants will be wearing MobilityLabTM (APDM, Portland, OR) sensors on their chest, lower back, wrists and feet during these tests to collect computerized sway data.

The short physical performance battery (SPPB) consists of gait speed as determined by a four-meter walk, timed repeated chair rise and standing balance. Gait speed will be measured by instructing participants to walk four meters at their normal pace; timed with a stopwatch and is repeated twice. The walk performed in the least time will be utilized for SPPB scoring purposes. The timed repeated chair rise has participants stand up from a chair five times without the use of their arms, if possible. Time to complete five stands is measured. Standing balance is assessed by having the participants stand in three positions of increasing difficulty for 10 seconds each. Standardized instructions will be given to all participants and the test performed twice. The SPPB will be conducted and scored in standard manner, score 0-12, with lower scores indicating mobility limitations. Participants will be wearing MobilityLabTM sensors to collect computerized data for these tests.

The Timed-Up-and-Go (TUG) test will be performed twice; participants will be seated in an armless chair, upon instruction, they will be asked to stand, which starts the timing, they will walk 3 meters past a mark on the floor at their normal pace, turn around and return to a full seated position, at which time the test will end.

An ImpediMed SFB7 device (Eight Mile Plains, Queensland, Australia) will be used to obtain these measurements. Participants will be positioned supine for a minimum of 10 minutes prior to acquisition; adequate separation of their legs will be obtained to allow for accurate BIS measurement. Measurements will be obtained by placing four EKG-like electrodes on the skin of the participant's hand, feet and knee. Wires will be attached from the BIS device to these skin electrodes. Painless electric waves will be sent through the tissues as noted above. Each measurement lasts only a few seconds. This method will generate measurements of lean mass.

Exercise enjoyment for each intervention was assessed using the validated questionnaire, "5-point Likert scale." Response options include "strongly agree", "agree", "neutral", "disagree", "strongly agree".

Self-reported pre- and post-training pain during the vibration intervention and control sessions were calculated as the mean for each participant using a validated questionnaire, "Comprehensive Pain Assessment Form" with scale from 0-10, 0 being no pain and 10 being severe pain.